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Søgeord (malaria) valgt.
77 emner vises.
Malaria Journal, 16.05.2024
Tilføjet 16.05.2024
Abstract Background Vector control using insecticides is a key prevention strategy against malaria. Unfortunately, insecticide resistance in mosquitoes threatens all progress in malaria control. In the perspective of managing this resistance, new insecticide formulations are being tested to improve the effectiveness of vector control tools. Methods The efficacy and residual activity of Pirikool® 300 CS was evaluated in comparison with Actellic® 300 CS in experimental huts at the Tiassalé experimental station on three substrates including cement, wood and mud. The mortality, blood-feeding inhibition, exiting behaviour and deterrency of free-flying wild mosquitoes was evaluated. Cone bioassay tests with susceptible and resistant mosquito strains were conducted in the huts to determine residual efficacy. Results A total of 20,505 mosquitoes of which 10,979 (53%) wild female Anopheles gambiae were collected for 112 nights. Residual efficacy obtained from monthly cone bioassay was higher than 80% with the susceptible, laboratory-maintained An. gambiae Kisumu strain, from the first to the tenth study period on all three types of treated substrate for both Actellic® 300CS and Pirikool® 300CS. This residual efficacy on the wild Tiassalé strain was over 80% until the 4th month of study on Pirikool® 300CS S treated substrates. Overall 24-h mortalities of wild free-flying An. gambiae sensu lato which entered in the experimental huts over the 8-months trial on Pirikool® 300CS treatment was 50.5%, 75.9% and 52.7%, respectively, on cement wall, wood wall and mud wall. The positive reference product Actellic® 300CS treatment induced mortalities of 42.0%, 51.8% and 41.8% on cement wall, wood wall and mud wall. Conclusion Pirikool® 300CS has performed really well against resistant strains of An. gambiae using indoor residual spraying method in experimental huts. It could be an alternative product for indoor residual spraying in response to the vectors\' resistance to insecticides.
Læs mere Tjek på PubMedMalaria Journal, 16.05.2024
Tilføjet 16.05.2024
Abstract Background In Uganda, village health workers (VHWs) manage childhood illness under the integrated community case management (iCCM) strategy. Care is provided for malaria, pneumonia, and diarrhoea in a community setting. Currently, there is limited evidence on the cost-effectiveness of iCCM in comparison to health facility-based management for childhood illnesses. This study examined the cost-effectiveness of the management of childhood illness using the VHW-led iCCM against health facility-based services in rural south-western Uganda. Methods Data on the costs and effectiveness of VHW-led iCCM versus health facility-based services for the management of childhood illness was collected in one sub-county in rural southwestern Uganda. Costing was performed using the ingredients approach. Effectiveness was measured as the number of under-five children appropriately treated. The Incremental Cost-Effectiveness Ratio (ICER) was calculated from the provider perspective. Results Based on the decision model for this study, the cost for 100 children treated was US$628.27 under the VHW led iCCM and US$87.19 for the health facility based services, while the effectiveness was 77 and 71 children treated for VHW led iCCM and health facility-based services, respectively. An ICER of US$6.67 per under five-year child treated appropriately for malaria, pneumonia and diarrhoea was derived for the provider perspective. Conclusion The health facility based services are less costly when compared to the VHW led iCCM per child treated appropriately. The VHW led iCCM was however more effective with regard to the number of children treated appropriately for malaria, pneumonia and diarrhoea. Considering the public health expenditure per capita for Uganda as the willingness to pay threshold, VHW led iCCM is a cost-effective strategy. VHW led iCCM should, therefore, be enhanced and sustained as an option to complement the health facility-based services for treatment of childhood illness in rural contexts.
Læs mere Tjek på PubMedMalaria Journal, 16.05.2024
Tilføjet 16.05.2024
Abstract Background In 2020, during the COVID-19 pandemic, Médecins Sans Frontières (MSF) initiated three cycles of dihydroartemisin-piperaquine (DHA-PQ) mass drug administration (MDA) for children aged three months to 15 years within Bossangoa sub-prefecture, Central African Republic. Coverage, clinical impact, and community members perspectives were evaluated to inform the use of MDAs in humanitarian emergencies. Methods A household survey was undertaken after the MDA focusing on participation, recent illness among eligible children, and household satisfaction. Using routine surveillance data, the reduction during the MDA period compared to the same period of preceding two years in consultations, malaria diagnoses, malaria rapid diagnostic test (RDT) positivity in three MSF community healthcare facilities (HFs), and the reduction in severe malaria admissions at the regional hospital were estimated. Twenty-seven focus groups discussions (FGDs) with community members were conducted. Results Overall coverage based on the MDA card or verbal report was 94.3% (95% confidence interval (CI): 86.3–97.8%). Among participants of the household survey, 2.6% (95% CI 1.6–40.3%) of round 3 MDA participants experienced illness in the preceding four weeks compared to 30.6% (95% CI 22.1–40.8%) of MDA non-participants. One community HF experienced a 54.5% (95% CI 50.8–57.9) reduction in consultations, a 73.7% (95% CI 70.5–76.5) reduction in malaria diagnoses, and 42.9% (95% CI 36.0–49.0) reduction in the proportion of positive RDTs among children under five. A second community HF experienced an increase in consultations (+ 15.1% (− 23.3 to 7.5)) and stable malaria diagnoses (4.2% (3.9–11.6)). A third community HF experienced an increase in consultations (+ 41.1% (95% CI 51.2–31.8) and malaria diagnoses (+ 37.3% (95% CI 47.4–27.9)). There were a 25.2% (95% CI 2.0–42.8) reduction in hospital admissions with severe malaria among children under five from the MDA area. FGDs revealed community members perceived less illness among children because of the MDA, as well as fewer hospitalizations. Other indirect benefits such as reduced household expenditure on healthcare were also described. Conclusion The MDA achieved high coverage and community acceptance. While some positive health impact was observed, it was resource intensive, particularly in this rural context. The priority for malaria control in humanitarian contexts should remain diagnosis and treatment. MDA may be additional tool where the context supports its implementation.
Læs mere Tjek på PubMedElizabeth Waymire, Jeanne N. Samake, Isuru Gunarathna, Tamar E. Carter
Trends in Parasitology, 16.05.2024
Tilføjet 16.05.2024
Anopheles stephensi is an invasive malaria vector in Africa that has been implicated in malaria outbreaks in the Horn of Africa. In 10 years, it has been detected as far east as Djibouti and as far west as Ghana. Early detections were mostly incidental, but now active surveillance in Africa has been updated to include An. stephensi. Morphological identification of An. stephensi from native vectors can be challenging, thus, sequence-based assays have been used to confirm identification during initial detections. Methods of sequence-based identification of An. stephensi have varied across initial detections to date. Here, we summarize initial detections, make suggestions that could provide a standardized approach, and discuss how sequences can inform additional genomic studies beyond species identification.
Læs mere Tjek på PubMedRahmat Dapari, Muhamad Zazali Fikri Mohd Yusop, Dharsshini Chinnasamy, Nurul Izati Zakaria, Siti Munisah Mohd Shoaib, Mohd Erfan Edros
PLoS One Infectious Diseases, 16.05.2024
Tilføjet 16.05.2024
by Rahmat Dapari, Muhamad Zazali Fikri Mohd Yusop, Dharsshini Chinnasamy, Nurul Izati Zakaria, Siti Munisah Mohd Shoaib, Mohd Erfan Edros Introduction Malaria is a vector-borne disease that initially manifests as fever, headache, and chills. The illness could progress to more severe conditions, including lethargy, impaired consciousness, convulsions, shortness of breath, blood in urine, jaundice, and haemorrhage if left untreated. The risk of contracting malaria is considerably heightened in specific occupational settings, particularly among forest rangers, following frequent exposure to natural habitats. Consequently, advancing the understanding of malaria and emphasising how specific occupational environments (including those of forest rangers) contribute to disease risk and management is imperative. Objective The present study aims to determine the factors associated with malaria infection among forest rangers by systematically reviewing electronic articles from three databases (EBSCOhost, ScienceDirect, and ResearchGate). Methods The current review was prepared based on the updated preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. First, three independent reviewers screened the titles and abstracts of the data collected. The information was then stored in Endnote20 based on the inclusion and exclusion criteria. The articles were critically appraised with the mixed methods appraisal tool (MMAT) to assess their quality. Result A total of 103, 31, and 51 articles from EBSCOhost, ScienceDirect, and ResearchGate, respectively, were selected, resulting in 185 unique hits. Nevertheless, only 63 full-text publications were assessed following a rigorous selection screening, from which only five were included in the final review. The studies revealed that several factors contribute to malaria infection among forest rangers. The parameters were classified into sociodemographic, individual, and living condition-related. Conclusion A better understanding of malaria progresses and identifying its potential risk factors is essential to impact worker well-being. The findings might be utilised to improve malaria infection prevention programme implementations, hence maximising their success. Pre-employment and regular health screenings could also aid in evaluating and identifying potential risks for malaria infection among forest rangers.
Læs mere Tjek på PubMedBMC Infectious Diseases, 15.05.2024
Tilføjet 15.05.2024
Abstract Background Malaria in pregnancy remains a major public health problem in the globe, especially in sub-Saharan Africa. In malaria endemic areas, most pregnant women remain asymptomatic, but malaria could still cause complications on the mother and her offspring; as well as serve as reservoirs to transmit infection. Despite these effects, no attention is given to the diagnosis of asymptomatic Plasmodium infections (APIs) using highly sensitive and specific laboratory diagnostic tools in Ethiopia. Therefore, the goal of this study was to compare the performance of Rapid Diagnostic Test (RDT), microscopy and real-time polymerase chain reaction (RT-PCR) to detect APIs among pregnant women. Methods A health facility based cross -sectional study was conducted among pregnant women attending antenatal care at Fendeka town health facilities Jawi district, northwest Ethiopia from February to March, 2019. A total of 166 participants were enrolled by using convenient sampling technique. Socio-demographic features were collected using a semi structured questionnaire. Dried blood spot (DBS) samples were collected for molecular analysis. Asymptomatic Plasmodium infection on pregnant women was diagnosed using RDT, microscopy and RT-PCR. Descriptive statistics were used to determine the prevalence of APIs. Method comparison was performed, and Cohen’s kappa coefficient (k) was used to determine the degree of agreement among the diagnostic methods. Parasite densities were also calculated. Results The prevalence of API was 9.6%, 11.4% and 18.7% using RDT, microscopy and RT-PCR, respectively. The overall proportion of API was 19.3%. Sensitivity of the RDT was 83.3% as compared with microscopy. Rapid Diagnostic Test and microscopy also showed sensitivity of 50% and 60%, respectively, as compared with RT-PCR. The mean parasite density was 3213 parasites/µl for P falciparum and 1140 parasites/µl of blood for P. vivax. Conclusion Prevalence of API in the study area was high. Both RDT and microscopy had lower sensitivity when compared with RT-PCR. Therefore, routine laboratory diagnosis of API among pregnant women should be given attention and done with better sensitive and specific laboratory diagnostic tools.
Læs mere Tjek på PubMedNicholas M. Anstey, Wai-Hong Tham, G. Dennis Shanks, Jeanne R. Poespoprodjo, Bruce M. Russell, Steven Kho
Trends in Parasitology, 15.05.2024
Tilføjet 15.05.2024
Plasmodium vivax contributes significantly to global malaria morbidity. Key advances include the discovery of pathways facilitating invasion by P. vivax merozoites of nascent reticulocytes, crucial for vaccine development. Humanized mouse models and hepatocyte culture systems have enhanced understanding of hypnozoite biology. The spleen has emerged as a major reservoir for asexual vivax parasites, replicating in an endosplenic life cycle, and contributing to recurrent and chronic infections, systemic inflammation, and anemia. Splenic accumulation of uninfected red cells is the predominant cause of anemia. Recurring and chronic infections cause progressive anemia, malnutrition, and death in young children in high-transmission regions. Endothelial activation likely contributes to vivax-associated organ dysfunction. The many recent advances in vivax pathobiology should help guide new approaches to prevention and management.
Læs mere Tjek på PubMedFatou Ndiaye, Abdoulaye Diop, Joseph Chabi, Katherine Sturm-Ramirez, Massila Senghor, El Hadji Diouf, Badara Samb, Seynabou Mocote Diedhiou, Omar Thiaw, Sarah Zohdy, Ellen Dotson, Doudou Sene, Mame Birame Diouf, Valerie Koscelnik, Lilia Gerberg, Abdoulaye Bangoura, Tiffany Clark, Ousmane Faye, Ibrahima Dia, Lassana Konate, El Hadji Amadou Niang
PLoS One Infectious Diseases, 15.05.2024
Tilføjet 15.05.2024
by Fatou Ndiaye, Abdoulaye Diop, Joseph Chabi, Katherine Sturm-Ramirez, Massila Senghor, El Hadji Diouf, Badara Samb, Seynabou Mocote Diedhiou, Omar Thiaw, Sarah Zohdy, Ellen Dotson, Doudou Sene, Mame Birame Diouf, Valerie Koscelnik, Lilia Gerberg, Abdoulaye Bangoura, Tiffany Clark, Ousmane Faye, Ibrahima Dia, Lassana Konate, El Hadji Amadou Niang Urban malaria has become a challenge for most African countries due to urbanization, with increasing population sizes, overcrowding, and movement into cities from rural localities. The rapid expansion of cities with inappropriate water drainage systems, abundance of water storage habitats, coupled with recurrent flooding represents a concern for water-associated vector borne diseases, including malaria. This situation could threaten progress made towards malaria elimination in sub-Saharan countries, including Senegal, where urban malaria has presented as a threat to national elimination gains. To assess drivers of urban malaria in Senegal, a 5-month study was carried out from August to December 2019 in three major urban areas and hotspots for malaria incidence (Diourbel, Touba, and Kaolack) including the rainy season (August-October) and partly dry season (November–December). The aim was to characterize malaria vector larval habitats, vector dynamics across both seasons, and to identify the primary eco- environmental entomological factors contributing to observed urban malaria transmission. A total of 145 Anopheles larval habitats were found, mapped, and monitored monthly. This included 32 in Diourbel, 83 in Touba, and 30 in Kaolack. The number of larval habitats fluctuated seasonally, with a decrease during the dry season. In Diourbel, 22 of the 32 monitored larval habitats (68.75%) were dried out by December and considered temporary, while the remaining 10 (31.25%) were classified as permanent. In the city of Touba 28 (33.73%) were temporary habitats, and of those 57%, 71% and 100% dried up respectively by October, November, and December. However, 55 (66.27%) habitats were permanent water storage basins which persisted throughout the study. In Kaolack, 12 (40%) permanent and 18 (60%) temporary Anopheles larval habitats were found and monitored during the study. Three malaria vectors (An. arabiensis, An. pharoensis and An. funestus s.l.) were found across the surveyed larval habitats, and An. arabiensis was found in all three cities and was the only species found in the city of Diourbel, while An. arabiensis, An. pharoensis, and An. funestus s.l. were detected in the cities of Touba and Kaolack. The spatiotemporal observations of immature malaria vectors in Senegal provide evidence of permanent productive malaria vector larval habitats year-round in three major urban centers in Senegal, which may be driving high urban malaria incidence. This study aimed to assess the presence and type of anopheline larvae habitats in urban areas. The preliminary data will better inform subsequent detailed additional studies and seasonally appropriate, cost-effective, and sustainable larval source management (LSM) strategies by the National Malaria Control Programme (NMCP).
Læs mere Tjek på PubMedBMC Infectious Diseases, 14.05.2024
Tilføjet 14.05.2024
Abstract Background Malaria in pregnancy remains a major public health problem in the globe, especially in sub-Saharan Africa. In malaria endemic areas, most pregnant women remain asymptomatic, but malaria could still cause complications on the mother and her offspring; as well as serve as reservoirs to transmit infection. Despite these effects, no attention is given to the diagnosis of asymptomatic Plasmodium infections (APIs) using highly sensitive and specific laboratory diagnostic tools in Ethiopia. Therefore, the goal of this study was to compare the performance of Rapid Diagnostic Test (RDT), microscopy and real-time polymerase chain reaction (RT-PCR) to detect APIs among pregnant women. Methods A health facility based cross -sectional study was conducted among pregnant women attending antenatal care at Fendeka town health facilities Jawi district, northwest Ethiopia from February to March, 2019. A total of 166 participants were enrolled by using convenient sampling technique. Socio-demographic features were collected using a semi structured questionnaire. Dried blood spot (DBS) samples were collected for molecular analysis. Asymptomatic Plasmodium infection on pregnant women was diagnosed using RDT, microscopy and RT-PCR. Descriptive statistics were used to determine the prevalence of APIs. Method comparison was performed, and Cohen’s kappa coefficient (k) was used to determine the degree of agreement among the diagnostic methods. Parasite densities were also calculated. Results The prevalence of API was 9.6%, 11.4% and 18.7% using RDT, microscopy and RT-PCR, respectively. The overall proportion of API was 19.3%. Sensitivity of the RDT was 83.3% as compared with microscopy. Rapid Diagnostic Test and microscopy also showed sensitivity of 50% and 60%, respectively, as compared with RT-PCR. The mean parasite density was 3213 parasites/µl for P falciparum and 1140 parasites/µl of blood for P. vivax. Conclusion Prevalence of API in the study area was high. Both RDT and microscopy had lower sensitivity when compared with RT-PCR. Therefore, routine laboratory diagnosis of API among pregnant women should be given attention and done with better sensitive and specific laboratory diagnostic tools.
Læs mere Tjek på PubMedBMC Infectious Diseases, 14.05.2024
Tilføjet 14.05.2024
Abstract Background Malaria in pregnancy remains a major public health problem in the globe, especially in sub-Saharan Africa. In malaria endemic areas, most pregnant women remain asymptomatic, but malaria could still cause complications on the mother and her offspring; as well as serve as reservoirs to transmit infection. Despite these effects, no attention is given to the diagnosis of asymptomatic Plasmodium infections (APIs) using highly sensitive and specific laboratory diagnostic tools in Ethiopia. Therefore, the goal of this study was to compare the performance of Rapid Diagnostic Test (RDT), microscopy and real-time polymerase chain reaction (RT-PCR) to detect APIs among pregnant women. Methods A health facility based cross -sectional study was conducted among pregnant women attending antenatal care at Fendeka town health facilities Jawi district, northwest Ethiopia from February to March, 2019. A total of 166 participants were enrolled by using convenient sampling technique. Socio-demographic features were collected using a semi structured questionnaire. Dried blood spot (DBS) samples were collected for molecular analysis. Asymptomatic Plasmodium infection on pregnant women was diagnosed using RDT, microscopy and RT-PCR. Descriptive statistics were used to determine the prevalence of APIs. Method comparison was performed, and Cohen’s kappa coefficient (k) was used to determine the degree of agreement among the diagnostic methods. Parasite densities were also calculated. Results The prevalence of API was 9.6%, 11.4% and 18.7% using RDT, microscopy and RT-PCR, respectively. The overall proportion of API was 19.3%. Sensitivity of the RDT was 83.3% as compared with microscopy. Rapid Diagnostic Test and microscopy also showed sensitivity of 50% and 60%, respectively, as compared with RT-PCR. The mean parasite density was 3213 parasites/µl for P falciparum and 1140 parasites/µl of blood for P. vivax. Conclusion Prevalence of API in the study area was high. Both RDT and microscopy had lower sensitivity when compared with RT-PCR. Therefore, routine laboratory diagnosis of API among pregnant women should be given attention and done with better sensitive and specific laboratory diagnostic tools.
Læs mere Tjek på PubMedMalaria Journal, 14.05.2024
Tilføjet 14.05.2024
Abstract Background Monitoring therapeutic efficacy is important to ensure the efficacy of artemisinin-based combination therapy (ACT) for malaria. The current first-line treatment for uncomplicated malaria recommended by the National Malaria Control Program in Niger is artemether–lumefantrine (AL). In 2020, an in vivo study was carried out to evaluate clinical and parasitological responses to AL as well as the molecular resistance to the drug in three sentinel sites: Agadez, Tessaoua and Gaya, in Niger. Methods A multi-center, single-arm trial was conducted according to the 28-day World Health Organization (WHO) 2009 therapeutic efficacy study protocol. Children between 6 months and 15 years with confirmed uncomplicated Plasmodium falciparum infection and 1000–200,000 asexual parasites/μL of blood were enrolled and followed up for 28 days. Uncorrected and PCR-corrected efficacy results at day 28 were calculated, and molecular correction was performed by genotyping the msp1, msp2, and glurp genes. The pfk13, pfdhfr, pfdhps, pfcrt and pfmdr genes were analyzed by PCR and Sanger sequencing. The Kaplan–Meier curve assessed parasite clearance. Results A total of 255 patients were enrolled in the study. The adequate clinical and parasitological response after PCR correction was 98.9% (95% CI 96.4–101.0%), 92.2% (85.0–98.5%) and 97.1% (93.1–101.0%) in Gaya, Tessaoua and Agadez, respectively. No adverse events were observed. Ten mutations (SNP) were found, including 7 synonyms (K248K, G690G, E691E, E612E, C469C, G496G, P718P) and 3 non-synonyms (N594K, R255K, V714S). Two mutations emerged: N594K and V714S. The R255K mutation detected in Southeast Asia was also detected. The pfdhpsK540E and pfdhfrI164L mutations associated with high levels of resistance are absent. There is a reversal of chloroquine resistance. Conclusion The study findings indicate that AL is effective and well tolerated for the treatment of uncomplicated malaria in three sites in Niger. The emergence of a pfk13 mutation requires additional testing such as the Ring Stage Assay and CRISPR/Cas9 to confirm the role of these emerging mutations. Trial registration NCT05070520, October 7, 2021.
Læs mere Tjek på PubMedMalaria Journal, 14.05.2024
Tilføjet 14.05.2024
Abstract A single 300 mg dose of tafenoquine (an 8-aminoquinoline), in combination with a standard 3-day course of chloroquine, is approved in several countries for the radical cure (prevention of relapse) of Plasmodium vivax malaria in patients aged ≥ 16 years. Despite this, questions have arisen on the optimal dose of tafenoquine. Before the availability of tafenoquine, a 3-day course of chloroquine in combination with the 8-aminoquinoline primaquine was the only effective radical cure for vivax malaria. The World Health Organization (WHO)-recommended standard regimen is 14 days of primaquine 0.25 mg/kg/day or 7 days of primaquine 0.5 mg/kg/day in most regions, or 14 days of primaquine 0.5 mg/kg/day in East Asia and Oceania, however the long treatment courses of 7 or 14 days may result in poor adherence and, therefore, low treatment efficacy. A single dose of tafenoquine 300 mg in combination with a 3-day course of chloroquine is an important advancement for the radical cure of vivax malaria in patients without glucose-6-phosphate dehydrogenase (G6PD) deficiency, as the use of a single-dose treatment will improve adherence. Selection of a single 300 mg dose of tafenoquine for the radical cure of P. vivax malaria was based on collective efficacy and safety data from 33 studies involving more than 4000 trial participants who received tafenoquine, including over 800 subjects who received the 300 mg single dose. The safety profile of single-dose tafenoquine 300 mg is similar to that of standard-dosage primaquine 0.25 mg/kg/day for 14 days. Both primaquine and tafenoquine can cause acute haemolytic anaemia in individuals with G6PD deficiency; severe haemolysis can lead to anaemia, kidney damage, and, in some cases, death. Therefore, relapse prevention using an 8-aminoquinoline must be balanced with the need to avoid clinical haemolysis associated with G6PD deficiency. To minimize this risk, the WHO recommends G6PD testing for all individuals before the administration of curative doses of 8-aminoquinolines. In this article, the authors review key efficacy and safety data from the pivotal trials of tafenoquine and argue that the currently approved dose represents a favourable benefit–risk profile.
Læs mere Tjek på PubMedMalaria Journal, 13.05.2024
Tilføjet 13.05.2024
Abstract Background The newly developed malaria vaccine called “R21/Matrix-M malaria vaccine” showed a high safety and efficacy level, and Ghana is the first country to approve this new vaccine. The present study aimed to evaluate the rate of vaccine hesitancy (VH) towards the newly developed malaria vaccine among parents who currently have children who are not eligible for the vaccine but may be eligible in the near future. Additionally, the study aimed to identify the factors that could potentially influence VH. Methods A cross-sectional survey using both online-based questionnaires and face-to-face interviews was conducted in Ghana from June to August 2023. The survey specifically targeted parents of ineligible children for vaccination, including those aged less than 5 months or between 3 and 12 years. The Parent Attitudes about Childhood Vaccination (PACV) scale was used to assess parental VH. Results A total of 765 people participated in this study. Their median age was 36.0 years with an interquartile range of 31.0–41.0 years, 67.7% were females, 41.8% completed their tertiary education, 63.3% were married, 81.6% worked in non-healthcare sectors, and 59.7% reported that their monthly income was insufficient. About one-third (34.5%) of the parents were hesitant to give their children the R21/Matrix-M malaria vaccine. The following predictors were associated with VH: working in the healthcare sector (adjusted odds ratio (AOR) = 0.50; 95% confidence interval (CI) 0.30–0.80; p = 0.005), having the other parent working in the healthcare sector (AOR = 0.54; 95% CI 0.30–0.94; p = 0.034), and not taking scheduled routine vaccinations (AOR = 1.90; 95% CI 1.27–2.84; p = 0.002). Conclusions Addressing VH is crucial for optimizing R21/Matrix-M vaccine coverage in Ghana\'s malaria control strategy. By tackling VH issues, Ghana can effectively safeguard children\'s health in malaria-prone areas.
Læs mere Tjek på PubMedMalaria Journal, 13.05.2024
Tilføjet 13.05.2024
Abstract Background Despite continuous prevention and control strategies in place, malaria remains a major public health problem in sub-Saharan Africa including Ethiopia. Moreover, prevalence of malaria differs in different geographical settings and epidemiological data were inadequate to assure disease status in the study area. This study was aimed to determine the prevalence of malaria and associated risk factors in selected rural kebeles in South Ethiopia. Methods A community-based cross-sectional study was conducted between February to June 2019 in eight malaria-endemic kebeles situated in four zones in South Ethiopia. Mult-stage sampling techniques were employed to select the study zones, districts, kebeles and households. Blood sample were collected from 1674 participants in 345 households by finger prick and smears were examined by microscopy. Sociodemographic data as well as risk factors for Plasmodium infection were collected using questionnaires. Bivariate and multivariate logistic regressions were used to analyse the data. Results The overall prevalence of malaria in the study localities was 4.5% (76/1674). The prevalence was varied among the study localities with high prevalence in Bashilo (14.6%; 33/226) followed by Mehal Korga (12.1%; 26/214). Plasmodium falciparum was the dominant parasite accounted for 65.8% (50/76), while Plasmodium vivax accounted 18.4% (14/76). Co-infection of P. falciparum and P. vivax was 15.8% (12/76). Among the three age groups prevalence was 7.8% (27/346) in age less than 5 years and 7.5% (40/531) in 5–14 years. The age groups > 14years were less likely infected with Plasmodium parasite (AOR = 0.14, 95% CI 0.02–0.82) than under five children. Non-febrile individuals 1638 (97.8%) were more likely to had Plasmodium infection (AOR = 28.4, 95% CI 011.4–70.6) than febrile 36 (2.2%). Individuals living proximity to mosquito breeding sites have higher Plasmodium infection (AOR = 6.17, 95% CI 2.66–14.3) than those at distant of breeding sites. Conclusions Malaria remains a public health problem in the study localities. Thus, malaria prevention and control strategies targeting children, non-febrile cases and individuals living proximity to breeding sites are crucial to reduce malaria related morbidity and mortality.
Læs mere Tjek på PubMedInfectious Disease Modelling, 12.05.2024
Tilføjet 12.05.2024
Publication date: Available online 11 May 2024 Source: Infectious Disease Modelling Author(s): Jinliang Wang, Wenjing Wu, Yuming Chen
Læs mere Tjek på PubMedMalaria Journal, 12.05.2024
Tilføjet 12.05.2024
Abstract Background The development of resistance by Plasmodium falciparum is a burdening hazard that continues to undermine the strides made to alleviate malaria. As such, there is an increasing need to find new alternative strategies. This study evaluated and validated 2 medicinal plants used in traditional medicine to treat malaria. Methods Inspired by their ethnobotanical reputation of being effective against malaria, Ziziphus mucronata and Xysmalobium undulutum were collected and sequentially extracted using hexane (HEX), ethyl acetate (ETA), Dichloromethane (DCM) and methanol (MTL). The resulting crude extracts were screened for their anti-malarial and cytotoxic potential using the parasite lactate dehydrogenase (pLDH) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, respectively. This was followed by isolating the active compounds from the DCM extract of Z. mucronata using silica gel chromatography and structural elucidation using spectroscopic techniques (NMR: 1H, 12C, and DEPT). The active compounds were then targeted against P. falciparum heat shock protein 70–1 (PfHsp70-1) using Autodock Vina, followed by in vitro validation assays using ultraviolet–visible (UV–VIS) spectroscopy and the malate dehydrogenase (MDH) chaperone activity assay. Results The extracts except those of methanol displayed anti-malarial potential with varying IC50 values, Z. mucronata HEX (11.69 ± 3.84 µg/mL), ETA (7.25 ± 1.41 µg/mL), DCM (5.49 ± 0.03 µg/mL), and X. undulutum HEX (4.9 ± 0.037 µg/mL), ETA (17.46 ± 0.024 µg/mL) and DCM (19.27 ± 0.492 µg/mL). The extracts exhibited minimal cytotoxicity except for the ETA and DCM of Z. mucronata with CC50 values of 10.96 and 10.01 µg/mL, respectively. Isolation and structural characterization of the active compounds from the DCM extracts revealed that betulinic acid (19.95 ± 1.53 µg/mL) and lupeol (7.56 ± 2.03 µg/mL) were responsible for the anti-malarial activity and had no considerable cytotoxicity (CC50 > µg/mL). Molecular docking suggested strong binding between PfHsp70-1, betulinic acid (− 6.8 kcal/mol), and lupeol (− 6.9 kcal/mol). Meanwhile, the in vitro validation assays revealed the disruption of the protein structural elements and chaperone function. Conclusion This study proves that X undulutum and Z. mucronata have anti-malarial potential and that betulinic acid and lupeol are responsible for the activity seen on Z. mucronata. They also make a case for guided purification of new phytochemicals in the other extracts and support the notion of considering medicinal plants to discover new anti-malarials.
Læs mere Tjek på PubMedJournal of Infectious Diseases, 11.05.2024
Tilføjet 11.05.2024
Abstract Neutrophils possess a diverse repertoire of pathogen clearance mechanisms, one of which is the formation of neutrophil extracellular traps (NETs). NETs are complexes of histone proteins and DNA coated with proteolytic enzymes that are released extracellularly to entrap pathogens and aid in their clearance, in a process known as NETosis. Intravascular NETosis may drive a massive inflammatory response that has been shown to contribute to morbidity and mortality in many infectious diseases, including malaria, dengue fever, influenza, bacterial sepsis, and SARS-CoV-2 infection.In this review we seek to: (1) summarize the current understanding of NETs; (2) discuss infectious diseases in which NET formation contributes to morbidity and mortality; and (3) explore potential adjunctive therapeutics that may be considered for future study in treating severe infections driven by NET pathophysiology. This includes drugs specifically targeting NET inhibition and FDA-approved drugs that may be repurposed as NET inhibitors.
Læs mere Tjek på PubMedJournal of Infectious Diseases, 11.05.2024
Tilføjet 11.05.2024
Abstract Maintaining high affinity antibodies after vaccination may be important for long-lasting immunity to malaria, but data on induction and kinetics of affinity is lacking. In a Phase 1 malaria vaccine trial, antibody affinity increased following a second vaccination but declined substantially over 12-months, suggesting poor maintenance of high affinity antibodies.
Læs mere Tjek på PubMedMark W. Smith, Thomas Willis, Elizabeth Mroz, William H. M. James, Megan J. Klaar, Simon N. Gosling, Christopher J. Thomas
Science, 10.05.2024
Tilføjet 10.05.2024
Malaria Journal, 10.05.2024
Tilføjet 10.05.2024
Abstract Background Plasmodium vivax relapses due to dormant liver hypnozoites can be prevented with primaquine. However, the dose must be adjusted in individuals with glucose-6-phosphate-dehydrogenase (G6PD) deficiency. In French Guiana, assessment of G6PD activity is typically delayed until day (D)14 to avoid the risk if misclassification. This study assessed the kinetics of G6PD activity throughout P. vivax infection to inform the timing of treatment. Methods For this retrospective monocentric study, data on G6PD activity between D1 and D28 after treatment initiation with chloroquine or artemisinin-based combination therapy were collected for patients followed at Cayenne Hospital, French Guiana, between January 2018 and December 2020. Patients were divided into three groups based on the number of available G6PD activity assessments: (i) at least two measurements during the P. vivax malaria infection; (ii) two measurements: one during the current infection and one previously; (iii) only one measurement during the malaria infection. Results In total, 210 patients were included (80, 20 and 110 in groups 1, 2 and 3, respectively). Data from group 1 showed that G6PD activity remained stable in each patient over time (D1, D3, D7, D14, D21, D28). None of the patients with normal G6PD activity during the initial phase (D1–D3) of the malaria episode (n = 44) was categorized as G6PD-deficient at D14. Patients with G6PD activity
Læs mere Tjek på PubMedMalaria Journal, 10.05.2024
Tilføjet 10.05.2024
Abstract Background In 2021 and 2023, the World Health Organization approved RTS,S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made of Plasmodium falciparum circumsporozoite protein (PfCSP), but polymorphisms in the gene raise concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed the Pfcsp genetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission intensities in Mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country. Methods The analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of Mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright’s inbreeding coefficient (Fws), Wright’s fixation index (FST), principal component analysis, nucleotide diversity, and Tajima’s D were used to assess within-host parasite diversity, population structure and natural selection. Results Based on Fws (
Læs mere Tjek på PubMedRahmat Dapari, Muhammad Fahmi Mohd Fadzil, Muhammad Yazid Hanzir, Jamal Sham Mohamed Jais, Nur Fatin Safarudin, Adila Albar
PLoS One Infectious Diseases, 9.05.2024
Tilføjet 9.05.2024
by Rahmat Dapari, Muhammad Fahmi Mohd Fadzil, Muhammad Yazid Hanzir, Jamal Sham Mohamed Jais, Nur Fatin Safarudin, Adila Albar Introduction Workers in the construction industry frequently work in construction sites with numerous areas that can potentially accumulate water, such as tanks, wet cement surfaces, or water puddles. These water collection sites become ideal breeding grounds for mosquito infestation, which leads to a higher prevalence of mosquito-borne diseases, especially malaria and dengue among construction workers. Despite that numerous factors have been identified in controlling vector-borne diseases, the specific factors that influence mosquito control at construction sites have yet to be explored. Aims This systematic review aims to determine the factors associated with mosquito control among construction workers. Methods Primarily, articles related to factors associated with mosquito control among construction workers were collected from two different online databases (ScienceDirect and EBSCOhost). Two independent reviewers were assigned to screen the titles and abstracts of the collected data, stored in Microsoft Excel, against the inclusion and exclusion criteria. Afterwards, the quality of the included articles was critically assessed using the Mixed Method Appraisal Tool (MMAT). Of the 171 articles identified, 4 were included in the final review. Results Based on the thorough evaluation, mosquito-related knowledge, practical mosquito prevention measures, and Larval Source Management (LSM) were identified as vital factors associated with mosquito control among construction workers. The significant association between mosquito-related knowledge and control practices indicates higher knowledge linked to effective practices, particularly among female workers and those who were recently infected with malaria. Concurrently, there were notable challenges regarding sustainable preventive measures and larval control methods in construction settings. Conclusion Implementing effective mosquito control, including knowledge and practice on mosquito control together with vector control, is highly required to suppress the expanding mosquito population. It is recommended that employers provide continuous mosquito control education and training to their employees and reward them with incentives, while employees should comply with the guidelines set by their employers to ensure successful mosquito control and reduce the spread of mosquito-borne diseases in the construction industry.
Læs mere Tjek på PubMedGarrett, Nigel; Dintwe, One; Monaco, Cynthia L.; Jones, Megan; Seaton, Kelly E.; Church, E. Chandler; Grunenberg, Nicole; Hutter, Julia; deCamp, Allan; Huang, Yunda; Lu, Huiyin; Mann, Philipp; Robinson, Samuel T.; Heptinstall, Jack; Jensen, Ryan L.; Pantaleo, Giuseppe; Ding, Song; Koutsoukos, Marguerite; Hosseinipour, Mina C.; Van Der Meeren, Olivier; Gilbert, Peter B.; Ferrari, Guido; Andersen-Nissen, Erica; McElrath, M. Juliana; Tomaras, Georgia D.; Gray, Glenda E.; Corey, Lawrence; Kublin, James G.; on behalf of the HVTN 108 and HVTN 111 Study Teams
Journal of Acquired Immune Deficiency Syndromes, 9.05.2024
Tilføjet 9.05.2024
Despite progress in HIV prevention and treatment, an estimated 1.3 million people were newly infected with HIV in 2022,1 highlighting the urgent need for an effective vaccine. To date, the RV144 trial remains the only HIV vaccine trial that has demonstrated partial efficacy against acquisition.2 The Pox-Protein Public-Private Partnership (P5) was established with the aims of improving on RV144 by developing a vaccine capable of protecting against a broader diversity of HIV strains and achieving a better understanding of immune responses associated with preventing HIV infection.3 Vaccine concepts in the P5 program have focused on clade C immunogens, targeting predominant strains of East and Southern Africa, where approximately half of the 39 million people living with HIV reside.1 Despite progress in HIV prevention and treatment, an estimated 1.3 million people were newly infected with HIV in 2022,1 highlighting the urgent need for an effective vaccine. To date, the RV144 trial remains the only HIV vaccine trial that has demonstrated partial efficacy against acquisition.2 The Pox-Protein Public-Private Partnership (P5) was established with the aims of improving on RV144 by developing a vaccine capable of protecting against a broader diversity of HIV strains and achieving a better understanding of immune responses associated with preventing HIV infection.3 Vaccine concepts in the P5 program have focused on clade C immunogens, targeting predominant strains of East and Southern Africa, where approximately half of the 39 million people living with HIV reside.1 The RV144 regimen, originally designed to protect against subtype B/E strains, was adapted to incorporate clade C antigens and adjuvanted with MF59®.4 This regimen demonstrated adequate immunogenicity in the HVTN100 phase 1/2a trial,5 and was further evaluated in the HVTN702 efficacy trial in South Africa, but ultimately discontinued due to non-efficacy.6 In parallel, the P5 designed the correlates program: a series of phase 1/2a trials to evaluate vaccine candidates based on favorable immune profiles of putative correlates of protection. These trials employed novel prime-boost and co-administration regimens, varied protein doses, and used new adjuvants and vaccine delivery systems, with an emphasis on shared immunological endpoints to allow for cross-study comparisons. Preclinical studies have shown promising immune responses using DNA/protein combination vaccines.7,8 A comparison of responses between HVTN100 (ALVAC) and HVTN111 (DNA) trials indicated that DNA priming with a protein boost led to increased antibody and cellular responses compared to priming with the canarypox vector.9 In the HVTN105 trial, both a DNA prime-protein boost and a co-administration regimen induced potent and durable V1/V2 binding antibody responses (a known correlate of lower HIV-1 infection risk in RV144), with co-administration inducing early antibody responses.10 Furthermore, in the HVTN096 trial, including gp120 Env protein at the priming stage, co-administered with either NYVAC or DNA, elicited earlier and even greater antibody responses.11 The adjuvant system 01 (AS01) has been successfully tested in vaccine trials for other infectious diseases including malaria,12 shingles,13,14 and tuberculosis.15 Some HIV vaccine studies have also used AS01 and have shown that it contributes to the induction of robust and persistent cellular and humoral responses.16,17 MF59® has likewise been used in several licensed vaccines and pre-clinical studies,18 inducing strong and durable T-cell memory and humoral responses. MF59® was also used in HVTN studies with ALVAC 5 and was therefore chosen for comparison with AS01B in this trial. Thus, the aim of the HVTN108 trial was to evaluate the safety and immunogenicity of the DNA vaccine with different HIV clade C protein doses, adjuvanted with MF59® or AS01B, and dosed in prime-boost or co-administration regimens. Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.
Læs mere Tjek på PubMedMalaria Journal, 8.05.2024
Tilføjet 8.05.2024
Abstract Background Artemisinin resistance in Plasmodium falciparum threatens global malaria elimination efforts. To contain and then eliminate artemisinin resistance in Eastern Myanmar a network of community-based malaria posts was instituted and targeted mass drug administration (MDA) with dihydroartemisinin-piperaquine (three rounds at monthly intervals) was conducted. The prevalence of artemisinin resistance during the elimination campaign (2013–2019) was characterized. Methods Throughout the six-year campaign Plasmodium falciparum positive blood samples from symptomatic patients and from cross-sectional surveys were genotyped for mutations in kelch-13—a molecular marker of artemisinin resistance. Result The program resulted in near elimination of falciparum malaria. Of 5162 P. falciparum positive blood samples genotyped, 3281 (63.6%) had K13 mutations. The prevalence of K13 mutations was 73.9% in 2013 and 64.4% in 2019. Overall, there was a small but significant decline in the proportion of K13 mutants (p
Læs mere Tjek på PubMedMalaria Journal, 8.05.2024
Tilføjet 8.05.2024
Abstract Background Universal coverage with insecticide-treated nets (ITNs) is important for malaria control and elimination. The emergence and intensification of insecticide resistance threatens progress made through the deployment of these interventions and has required the development of newer, more expensive ITN types. Understanding malaria prevention behaviour, including barriers and facilitators to net access and use, can support effective decision-making for the promotion and distribution of ITNs. Methods In-depth interviews and focus group discussions were conducted in 3 to 4 villages per district, in 13 districts across Burkina Faso, Mozambique, Nigeria and Rwanda from 2019 to 2022. Interviews were conducted in the local language, translated and transcribed in English, French or Portuguese. Transcripts were coded and analysed using Nvivo and ATLAS.ti. Results ITNs were obtained from mass distribution campaigns, antenatal care and immunization visits, and purchased on the private market in some locations. While there were divergent perspectives in whether the number of distributed nets were adequate, participants consistently expressed concerns of bias, discrimination, and a lack of transparency with the distribution process. ITNs were frequently used alongside other malaria prevention methods. The primary motivation for use was malaria prevention. While some participants reported using nets nightly throughout the year, other participants reported seasonal use, both due to the perceived higher density of mosquitoes and discomfort of sleeping under a net in the increased heat. Other barriers to consistent net use included activities that take place away from the home, sleeping patterns and arrangements, and sensitivity to the insecticides on the nets. Conclusions ITNs remain an important malaria control intervention. To ensure adequate and increased net access, distribution campaigns should consider family structures, available sleeping spaces, and other bed sharing preferences when identifying the number of nets needed for distribution. In addition, campaigns should allow for multiple options for net distribution points and timing to accommodate households remote to health services. Continuous distribution channels and complimentary distribution through the private sector could help fill gaps in coverage. Solutions are needed for outdoor malaria transmission, including alternative designs for ITNs, and improving access to complementary personal protective measures.
Læs mere Tjek på PubMedMalaria Journal, 8.05.2024
Tilføjet 8.05.2024
Abstract Background The direct membrane feeding assay (DMFA), whereby gametocyte-infected blood is collected from human donors and from which mosquitoes feed through a membrane, is proving essential for assessing parameters influencing Plasmodium transmission potential in endemic countries. The success of DMFAs is closely tied to gametocyte density in the blood, with relatively high gametocytaemia ensuring optimal infection levels in mosquitoes. As transmission intensity declines with control efforts, the occurrence of asymptomatic individuals with low gametocyte densities, who can significantly contribute to the infectious reservoir, is increasing. This poses a limitation to studies relying on the experimental infection of large numbers of mosquitoes with natural isolates of Plasmodium. A simple, field-applicable method is presented for improving parasite infectivity by concentrating Plasmodium falciparum gametocytes. Methods Anopheles gambiae received one of the following 5 blood treatments through DMFA: (i) whole blood (WB) samples from naturally-infected donors; (ii) donor blood whose plasma was replaced with the same volume of Plasmodium-naive AB + serum (1:1 control); (iii) plasma replaced with a volume of malaria-naïve AB + serum equivalent to half (1:1/2), or to a quarter (1:1/4), of the initial plasma volume; and (v) donor blood whose plasma was fully removed (RBC). The experiment was repeated 4 times using 4 distinct wild parasite isolates. Seven days post-infection, a total of 1,095 midguts were examined for oocyst presence. Results Substituting plasma with reduced amounts (1:1/2 and 1:1/4) of Plasmodium-naive AB + serum led to a 31% and 17% increase of the mosquito infection rate and to a 85% and 308% increase in infection intensity compared to the 1:1 control, respectively. The full removal of plasma (RBC) reduced the infection rate by 58% and the intensity by 64% compared to the 1:1 control. Reducing serum volumes (1:1/2; 1:1/4 and RBC) had no impact on mosquito feeding rate and survival when compared to the 1:1 control. Conclusions Concentrating gametocytic blood by replacing natural plasma by lower amount of naive serum can enhance the success of mosquito infection. In an area with low gametocyte density, this simple and practical method of parasite concentration can facilitate studies on human-to-mosquito transmission such as the evaluation of transmission-blocking interventions.
Læs mere Tjek på PubMedMalaria Journal, 8.05.2024
Tilføjet 8.05.2024
Abstract Malaria vaccine introduction in endemic countries is a game-changing milestone in the fight against the disease. This article examines the inequity in the global pharmaceutical research, development, manufacturing, and trade landscape. The role of inequity in hindering progress towards malaria elimination is explored. The analysis finds that transformational changes are required to create an equity-enabling environment. Addressing the inequity is critical to maximizing the public health impact of vaccines and attaining sustainability. Avenues to catalyze progress by leveraging malaria vaccines and messenger ribonucleic acid (mRNA) technology are discussed.
Læs mere Tjek på PubMedMalaria Journal, 8.05.2024
Tilføjet 8.05.2024
Abstract Background Studies on haemosporidian diversity, including origin of human malaria parasites, malaria\'s zoonotic dynamic, and regional biodiversity patterns, have used target gene approaches. However, current methods have a trade-off between scalability and data quality. Here, a long-read Next-Generation Sequencing protocol using PacBio HiFi is presented. The data processing is supported by a pipeline that uses machine-learning for analysing the reads. Methods A set of primers was designed to target approximately 6 kb, almost the entire length of the haemosporidian mitochondrial genome. Amplicons from different samples were multiplexed in an SMRTbell® library preparation. A pipeline (HmtG-PacBio Pipeline) to process the reads is also provided; it integrates multiple sequence alignments, a machine-learning algorithm that uses modified variational autoencoders, and a clustering method to identify the mitochondrial haplotypes/species in a sample. Although 192 specimens could be studied simultaneously, a pilot experiment with 15 specimens is presented, including in silico experiments where multiple data combinations were tested. Results The primers amplified various haemosporidian parasite genomes and yielded high-quality mt genome sequences. This new protocol allowed the detection and characterization of mixed infections and co-infections in the samples. The machine-learning approach converged into reproducible haplotypes with a low error rate, averaging 0.2% per read (minimum of 0.03% and maximum of 0.46%). The minimum recommended coverage per haplotype is 30X based on the detected error rates. The pipeline facilitates inspecting the data, including a local blast against a file of provided mitochondrial sequences that the researcher can customize. Conclusions This is not a diagnostic approach but a high-throughput method to study haemosporidian sequence assemblages and perform genotyping by targeting the mitochondrial genome. Accordingly, the methodology allowed for examining specimens with multiple infections and co-infections of different haemosporidian parasites. The pipeline enables data quality assessment and comparison of the haplotypes obtained to those from previous studies. Although a single locus approach, whole mitochondrial data provide high-quality information to characterize species pools of haemosporidian parasites.
Læs mere Tjek på PubMedMalaria Journal, 8.05.2024
Tilføjet 8.05.2024
Abstract Background Malaria is a potentially life-threatening disease caused by Plasmodium protozoa transmitted by infected Anopheles mosquitoes. Controlled human malaria infection (CHMI) trials are used to assess the efficacy of interventions for malaria elimination. The operating characteristics of statistical methods for assessing the ability of interventions to protect individuals from malaria is uncertain in small CHMI studies. This paper presents simulation studies comparing the performance of a variety of statistical methods for assessing efficacy of intervention in CHMI trials. Methods Two types of CHMI designs were investigated: the commonly used single high-dose design (SHD) and the repeated low-dose design (RLD), motivated by simian immunodeficiency virus (SIV) challenge studies. In the context of SHD, the primary efficacy endpoint is typically time to infection. Using a continuous time survival model, five statistical tests for assessing the extent to which an intervention confers partial or full protection under single dose CHMI designs were evaluated. For RLD, the primary efficacy endpoint is typically the binary infection status after a specific number of challenges. A discrete time survival model was used to study the characteristics of RLD versus SHD challenge studies. Results In a SHD study with the continuous time survival model, log-rank test and t-test are the most powerful and provide more interpretable results than Wilcoxon rank-sum tests and Lachenbruch tests, while the likelihood ratio test is uniformly most powerful but requires knowledge of the underlying probability model. In the discrete time survival model setting, SHDs are more powerful for assessing the efficacy of an intervention to prevent infection than RLDs. However, additional information can be inferred from RLD challenge designs, particularly using a likelihood ratio test. Conclusions Different statistical methods can be used to analyze controlled human malaria infection (CHMI) experiments, and the choice of method depends on the specific characteristics of the experiment, such as the sample size allocation between the control and intervention groups, and the nature of the intervention. The simulation results provide guidance for the trade off in statistical power when choosing between different statistical methods and study designs.
Læs mere Tjek på PubMedMalaria Journal, 8.05.2024
Tilføjet 8.05.2024
Abstract Background In Nigeria, seasonal malaria chemoprevention (SMC) is typically administered door-to-door to children under five by community medicine distributors during high transmission seasons. While door-to-door distribution (DDD) is exclusively employed in Nigeria as part of standard operating procedures of SMC programmes, some households access SMC through non-DDD channels, such as fixed-point distributions, health facilities, and private purchase. However, analysis of access to SMC medicines through non-DDD has been limited, with little evidence of its outcomes on adherence to the three-day complete course of SMC medicines and caregiver actions in the event of adverse reactions to SMC medicines. Methods Data were obtained from SMC end-of-round coverage surveys conducted in Nigeria in 2021 and 2022, including 25,278 households for the analysis. The proportion of households accessing SMC medicine through non-DDD and the distribution of various non-DDD sources of SMC medicines were described. Multivariate random-effects logistic regression models were performed to identify predictors of accessing SMC medicines through non-DDD. The associations between non-DDD, and caregiver-reporting of adherence to complete administration of SMC medicines and caregiver actions in the event of adverse reactions to SMC medicines were also assessed. Results Less than 2% (314/24003) of households accessed SMC medicines through non-DDD in the states surveyed. Over 60% of non-DDD access was via health facility personnel and community medicine distributors from different locations. Variables associated with non-DDD access included heads of household being born in the local state (OR = 0.68, 95% CI 0.47 to 0.90), households residing in the study state since the first cycle of the SMC round (OR = 0.39, 95% CI 0.17 to 0.88), households with high wealth index (OR = 1.36, 95% CI 1.01 to 1.82), and caregivers hearing about date of SMC delivery in the previous cycle (OR = 0.18, 95%CI 0.14 to 0.24). Furthermore, non-DDD was associated with reduced SMC adherence and higher caregiver non-reporting of adverse reactions to SMC medicines in children compared with DDD. Conclusion This study provides evidence on the characteristics of households accessing SMC medicines through non-DDD and its potential negative outcomes on adherence to SMC medicine and adverse reaction reporting, underscoring potential implementation issues that may arise if non-DDD delivery models are adopted in SMC, particularly in places where DDD had been firstly used.
Læs mere Tjek på PubMedMalaria Journal, 8.05.2024
Tilføjet 8.05.2024
Abstract Background Drug repurposing offers a strategic alternative to the development of novel compounds, leveraging the known safety and pharmacokinetic profiles of medications, such as linezolid and levofloxacin for tuberculosis (TB). Anti-malarial drugs, including quinolones and artemisinins, are already applied to other diseases and infections and could be promising for TB treatment. Methods This review included studies on the activity of anti-malarial drugs, specifically quinolones and artemisinins, against Mycobacterium tuberculosis complex (MTC), summarizing results from in vitro, in vivo (animal models) studies, and clinical trials. Studies on drugs not primarily developed for TB (doxycycline, sulfonamides) and any novel developed compounds were excluded. Analysis focused on in vitro activity (minimal inhibitory concentrations), synergistic effects, pre-clinical activity, and clinical trials. Results Nineteen studies, including one ongoing Phase 1 clinical trial, were analysed: primarily investigating quinolones like mefloquine and chloroquine, and, to a lesser extent, artemisinins. In vitro findings revealed high MIC values for anti-malarials versus standard TB drugs, suggesting a limited activity. Synergistic effects with anti-TB drugs were modest, with some synergy observed in combinations with isoniazid or pyrazinamide. In vivo animal studies showed limited activity of anti-malarials against MTC, except for one study of the combination of chloroquine with isoniazid. Conclusions The repurposing of anti-malarials for TB treatment is limited by high MIC values, poor synergy, and minimal in vivo effects. Concerns about potential toxicity at effective dosages and the risk of antimicrobial resistance, especially where TB and malaria overlap, further question their repurposing. These findings suggest that focusing on novel compounds might be both more beneficial and rewarding.
Læs mere Tjek på PubMedEnoch Aninagyei, John Gameli Deku, Keren Trishia Yemofio, Ekua Quainoo, Kofi Adjei Ntiri, Evelyn Yaro, Priscilla Essandoh, Hubert Kwame Agbogli, Richard Harry Asmah
PLoS One Infectious Diseases, 8.05.2024
Tilføjet 8.05.2024
by Enoch Aninagyei, John Gameli Deku, Keren Trishia Yemofio, Ekua Quainoo, Kofi Adjei Ntiri, Evelyn Yaro, Priscilla Essandoh, Hubert Kwame Agbogli, Richard Harry Asmah Malaria rapid diagnostic test (mRDT) kit is one of the techniques for diagnosing malaria. Due to its inherent advantages over the microscopy technique, several brands of the kit have flooded malaria endemic countries, without prior in-country evaluation. Two of such mRDT kits are Oscar (India) and Standard Q (Korea Republic). In this study, the performance of Oscar and Standard Q mRDT kits were compared to First Response (India) and CareStart (USA) mRDTs, which have been evaluated and deployed for use approved by the Ministry of Health (MOH). In this comparative study, whole blood samples were collected from patients suspected of malaria. Plasmodium falciparum was detected in each sample using nested polymerase chain reaction (nPCR), microscopy and the four mRDTs. The sensitivities, specificities, accuracies, positive and negative predictive values and accuracies of the mRDTs were determined using nPCR as a reference technique. Kappa statistic was used to determine the level of agreement among the techniques. Two hundred (200) blood samples were analyzed in this study. The overall detection rates of P. falciparum by microscopy, First Response, CareStart, Oscar-PfHRP2, Standard Q mRDT kits and nPCR were 31.5%, 34.5%, 33.5%, 32%, 31% and 43% (x2 = 6.1, p = 0.046), respectively. The accuracies of CareStart and First Response were comparable (90.5% vs. 89.5%). Further, comparing their sensitivities, Oscar-PfHRP2 was 74.4% (95% confidence interval (CI): 63.9–83.2) while that of Standard Q was 72.1% (95% CI: 61.4–81.2), with comparable accuracies (Oscar-PfHRP2–89% and Standard Q -88%). Apart from First Response that was 98.3% specific, the others were 100% specific. Kappa test revealed perfect diagnostic agreement (κ = 0.90–0.98) among the four mRDTs. That notwithstanding, Oscar-PfHRP2 agreed better with CareStart (κ = 0.94) and First Response (κ = 0.92) compared to the agreement between Standard Q and, CareStart (κ = 0.92) and First Response (κ = 0.90). Taken together, the diagnostic performance of the four mRDT kits were statistically similar. That notwithstanding, new mRDT kits should be evaluated prior to deployment for use.
Læs mere Tjek på PubMedCamila Marques-da-Silva, Clyde Schmidt-Silva, Samarchith P. Kurup
Trends in Parasitology, 7.05.2024
Tilføjet 7.05.2024
The Plasmodium parasites that cause malaria undergo asymptomatic development in the parenchymal cells of the liver, the hepatocytes, prior to infecting erythrocytes and causing clinical disease. Traditionally, hepatocytes have been perceived as passive bystanders that allow hepatotropic pathogens such as Plasmodium to develop relatively unchallenged. However, now there is emerging evidence suggesting that hepatocytes can mount robust cell-autonomous immune responses that target Plasmodium, limiting its progression to the blood and reducing the incidence and severity of clinical malaria. Here we discuss our current understanding of hepatocyte cell-intrinsic immune responses that target Plasmodium and how these pathways impact malaria.
Læs mere Tjek på PubMedMichal Juraska, Angela M Early, Li Li, Stephen F Schaffner, Marc Lievens, Akanksha Khorgade, Brian Simpkins, Nima S Hejazi, David Benkeser, Qi Wang, Laina D Mercer, Samuel Adjei, Tsiri Agbenyega, Scott Anderson, Daniel Ansong, Dennis K Bii, Patrick B Y Buabeng, Sean English, Nicholas Fitzgerald, Jonna Grimsby, Simon K Kariuki, Kephas Otieno, François Roman, Aaron M Samuels, Nelli Westercamp, Christian F Ockenhouse, Opokua Ofori-Anyinam, Cynthia K Lee, Bronwyn L MacInnis, Dyann F Wirth, Peter B Gilbert, Daniel E Neafsey
Lancet Infectious Diseases, 7.05.2024
Tilføjet 7.05.2024
All tested dosing regimens blocked some infections to a similar degree. Improved vaccine efficacy in participants infected during vaccination could suggest new strategies for highly efficacious malaria vaccine development and implementation.
Læs mere Tjek på PubMedReina Engle-Stone, K Ryan Wessells, Marjorie J. Haskell, Sika M. Kumordzie, Charles D. Arnold, Jennie N. Davis, Emily R. Becher, Ahmed D. Fuseini, Kania W. Nyaaba, Xiuping Tan, Katherine P. Adams, Georg Lietz, Stephen A. Vosti, Seth Adu-Afarwuah
PLoS One Infectious Diseases, 6.05.2024
Tilføjet 6.05.2024
by Reina Engle-Stone, K Ryan Wessells, Marjorie J. Haskell, Sika M. Kumordzie, Charles D. Arnold, Jennie N. Davis, Emily R. Becher, Ahmed D. Fuseini, Kania W. Nyaaba, Xiuping Tan, Katherine P. Adams, Georg Lietz, Stephen A. Vosti, Seth Adu-Afarwuah Introduction Micronutrient deficiencies are prevalent in West Africa, particularly among women of reproductive age (WRA) and young children. Bouillon is a promising food fortification vehicle due to its widespread consumption. This study aims to evaluate the impact of multiple micronutrient-fortified bouillon cubes, compared to control bouillon cubes (fortified with iodine only), on micronutrient status and hemoglobin concentrations among lactating and non-lactating WRA and young children in northern Ghana. Methods This randomized, controlled doubly-masked trial will be conducted in the Kumbungu and Tolon districts in the Northern Region of Ghana, where prior data indicate multiple micronutrient deficiencies are common. Participants will be: 1) non-pregnant non-lactating WRA (15–49 y), 2) children 2–5 y, and 3) non-pregnant lactating women 4–18 months postpartum. Eligible participants will be randomly assigned to receive household rations of one of two types of bouillon cubes: 1) a multiple micronutrient-fortified bouillon cube containing vitamin A, folic acid, vitamin B12, iron, zinc, and iodine, or 2) a control cube containing iodine only.Each participant’s household will receive a ration of bouillon cubes every 2 weeks, and households will be advised to prepare meals as usual, using the study-provided cubes. The trial duration will be 9 months for non-pregnant non-lactating WRA and children, and 3 months for lactating women. The primary outcomes will be changes in biomarkers of micronutrient status and hemoglobin among WRA and children and milk micronutrient concentrations among lactating women. Secondary outcomes will include change in prevalence of micronutrient deficiency and anemia; dietary intake of bouillon and micronutrients; inflammation, malaria, and morbidity symptoms; and child growth and development. Discussion Evidence from this study will inform discussions about bouillon fortification in Ghana and West Africa. Trial registration The trial was registered on ClinicalTrials.gov (NCT05178407) and the Pan-African Clinical Trial Registry (PACTR202206868437931). This manuscript reflects protocol version 4 (August 29, 2022).
Læs mere Tjek på PubMedShirin TaheriMikel Alexander GonzálezMaría José Ruiz-LópezSergio MagallanesSarah Delacour-EstrellaJavier LucientesRubén Bueno-MaríJosué Martínez-de la PuenteDaniel Bravo-BarrigaEva FronteraAlejandro PolinaYasmina Martinez-BarcielaJosé Manuel PereiraJosefina GarridoCarles ArandaAlfonso MarzalIgnacio Ruiz-ArrondoJosé Antonio OteoMartina FerragutiRafael Gutíerrez-LópezRosa EstradaMiguel Ángel MirandaCarlos BarcelóRodrigo MorchónTomas MontalvoLaura GangosoFátima GoiriAna L. García-PérezSantiago RuizBeatriz Fernandez-MartinezDiana Gómez-BarrosoJordi Figuerolaa Departamento de Biología de la Conservación y Cambio Global, Estación Biológica de Doñana (EBD), CSIC, Sevilla, Spainb CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, Spainc The Agrifood Institute of Aragón (IA2), Faculty of Veterinary Medicine, University of Zaragoza, Zaragoza, Spaind Center of Excellence in Vector Control, Rentokil Initial, València, Spaine Grupo de Investigación Parásitos y Salud, Universitat de València, València, Spainf Departamento de Parasitología, Universidad de Granada, Granada, Spaing Departamento de Salud Animal, Grupo de Investigación en Salud Animal y Zoonosis (GISAZ), Facultad de Veterinaria, Universidad de Córdoba, Córdoba, Spainh Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Extremadura (UEx), Cáceres, Spaini Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, Pontevedra, Spainj Departamento de Zooloxía, Xenética e Antropoloxía Física, Universidade de Santiago de Compostela, A Coruña, Spaink Servei de Control de Mosquits del Baix Llobregat, Sant Feliu del Llobregat, Barcelona, Spainl IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus Universitat Autònoma de Barcelona, Bellaterra, Spainm Facultad de Biología, Universidad de Extremadura, Badajoz, Spainn Grupo de Investigaciones en Fauna Silvestre, Universidad Nacional de San Martín, Tarapoto, Perúo Centre of Rickettsiosis and Arthropod-Borne Diseases, Hospital Universitario San Pedro-CIBIR, La Rioja, Logroño, Spainp Centro Nacional de Microbiología (CNM-ISCIII), Madrid, Spainq CIBER de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spainr Universitat de les Illes Balears (UIB), Zoología Aplicada y de la Conservación, Palma, Spains Zoonotic Diseases and One Health Group, Faculty of Pharmacy, Universidad de Salamanca, Salamanca, Spaint Agencia de Salut Publica de Barcelona, Barcelona, Spainu Universidad Complutense de Madrid, Madrid, Spainv NEIKER-Instituto Vasco de Investigación y Desarrollo Agrario, Derio, Spainw Servicio de Control de Mosquitos de la Diputación de Huelva, Huelva, Spainx Centro Nacional de Epidemiologia (CNE-ISCIII), Madrid, Spain
Emerg Microbes Infect, 3.05.2024
Tilføjet 3.05.2024
Jane M. Carlton and Aubrey J. Cunnington
Science, 3.05.2024
Tilføjet 3.05.2024
Harun K. Aremu, Christianah A. Dare, Idris A. Adekale, Bukunmi D. Adetunji, Dickson A. Musa, Luqmon A. Azeez, Olu I. Oyewole
PLoS One Infectious Diseases, 3.05.2024
Tilføjet 3.05.2024
by Harun K. Aremu, Christianah A. Dare, Idris A. Adekale, Bukunmi D. Adetunji, Dickson A. Musa, Luqmon A. Azeez, Olu I. Oyewole The incorporation of phytoactive compounds in the management of malarial vectors holds promise for the development of innovative and efficient alternatives. Nevertheless, the molecular and physiological responses that these bioactive substances induce remain underexplored. This present study investigated the toxicity of different concentrations of aqueous and methanol extracts of Ocimum tenuiflorum against larvae of Anopheles gambiae (sensu stricto) and unraveled the possible underlying molecular pathways responsible for the observed physiological effects. FTIR and GCMS analyses of phytoactive compounds in aqueous and methanol crude extracts of O. tenuiflorum showed the presence of OH stretching vibration, C = C stretching modes of aromatics and methylene rocking vibration; ring deformation mode with high levels of trans-β-ocimene, 3,7-dimethyl-1,3,6-octatriene in aqueous extract and 4-methoxy-benzaldehyde, 1,3,5-trimethyl-cyclohexane and o-cymene in methanol extract. The percentage mortality upon exposure to methanol and aqueous extracts of O. tenuiflorum were 21.1% and 26.1% at 24 h, 27.8% and 36.1% at 48 h and 36.1% and 45% at 72 h respectively. Using reverse transcription quantitative polymerase chain reaction (RT-qPCR), down-regulation of ABC transporter, overexpression of CYP6M2, Hsp70, and α-esterase, coupled with significantly increased levels of SOD, CAT, and GSH, were observed in An. gambiae (s.s.) exposed to aqueous and methanol extracts of O. tenuiflorum as compared to the control. Findings from this study have significant implications for our understanding of how An. gambiae (s.s.) larvae detoxify phytoactive compounds.
Læs mere Tjek på PubMedOmale, U. I., Ogbonnaya, L. U., Iyare, O., Nnachi, O. O.
BMJ Open, 2.05.2024
Tilføjet 2.05.2024
ObjectivesThe burden of malaria has persistently been high in Ebonyi state and Nigeria despite long-standing collaborations with international partners with huge and increased amounts of financial investments. We explored the system-wide governance challenges of the Ebonyi State Malaria Elimination Programme (SMEP) and the factors responsible in order to make recommendations for malaria health system strengthening. DesignWe did a qualitative study informed by the health system governance framework by Mikkelsen-Lopez et al and Savedoff’s concept of governance. Setting and participantsBetween 18 October 2022 and 8 November 2022, 25 semistructured face-to-face in-depth interviews were conducted in English with purposively selected key stakeholders in the Ebonyi SMEP aged 18 years or older with at least 2 years of involvement in the SMEP and who gave consent. AnalysisData were analysed deductively and the analytical strategy was informed by the framework method for the analysis of qualitative data by Gale et al. ResultsMany system-wide governance challenges of the SMEP were identified including the absence of state’s strategic vision and plans for malaria elimination; very weak primary and secondary healthcare systems; inadequate financial allocation and untimely release of budgeted funds by the state government; lack of human resources for health and very poor mosquito net distribution system. Other challenges were inadequate stakeholders’ participation; poor accountability culture; impaired transparency and corruption and impaired ability to address corruption. The fundamental responsible factors were the lack of state government’s concern for people’s welfare and lack of interest and commitment to the malaria elimination effort, chronic non-employment of staff and lack of human resources in the entire health sector including SMEP, and nepotism and godfatherism. ConclusionsThe system-wide governance challenges and the responsible factors call for changing the ‘business as usual’ and refocusing on strengthening malaria health system governance in addressing the persisting malaria health problems in Ebonyi state (and Nigeria).
Læs mere Tjek på PubMedMalaria Journal, 2.05.2024
Tilføjet 2.05.2024
Abstract Background The sequestration of Plasmodium falciparum infected erythrocytes in the placenta, and the resulting inflammatory response affects maternal and child health. Despite existing information, little is known about the direct impact of P. falciparum on the placental barrier formed by trophoblast and villous stroma. This study aimed to assess placental tissue damage caused by P. falciparum in human placental explants (HPEs). Methods HPEs from chorionic villi obtained of human term placentas (n = 9) from normal pregnancies were exposed to P. falciparum-infected erythrocytes (IE) for 24 h. HPEs were embedded in paraffin blocks and used to study tissue damage through histopathological and histochemical analysis and apoptosis using TUNEL staining. Culture supernatants were collected to measure cytokine and angiogenic factors and to determine LDH activity as a marker of cytotoxicity. A subset of archived human term placenta paraffin-embedded blocks from pregnant women with malaria were used to confirm ex vivo findings. Results Plasmodium falciparum-IE significantly damages the trophoblast layer and the villous stroma of the chorionic villi. The increased LDH activity and pathological findings such as syncytial knots, fibrin deposits, infarction, trophoblast detachment, and collagen disorganization supported these findings. The specific damage to the trophoblast and the thickening of the subjacent basal lamina were more pronounced in the ex vivo infection. In contrast, apoptosis was higher in the in vivo infection. This disparity could be attributed to the duration of exposure to the infection, which significantly varied between individuals naturally exposed over time and the 24-h exposure in the ex vivo HPE model. Conclusion Exposure to P. falciparum-IE induces a detachment of the syncytiotrophoblast, disorganization of the stroma villi, and an increase in apoptosis, alterations that may be associated with adverse results such as intrauterine growth restriction and low birth weight.
Læs mere Tjek på PubMedMalaria Journal, 2.05.2024
Tilføjet 2.05.2024
Abstract Background Malaria has remained a persistent global health problem. Despite multiple government and donor initiatives to eradicate malaria and its detrimental effects on Uganda\'s health outcomes, the incidence of malaria is worrying as it appears higher than the average of 219 cases per 1000 for sub-Saharan Africa for the period 2017–2018. This study investigated the effect of public and private healthcare spending on the incidence of malaria in Uganda. Methods Employing time series data spanning over 20 years from the first quarter of 2000 to the last quarter of 2019, the study builds a model based on the Grossman framework for analysing demand for health. The estimation technique used was the ARDL approach that takes into account reverse causality and incidental relationships. Prior to the adoption of the technique, a bounds test was performed to determine whether the variables contained in the model have a long-term relationship. Several diagnostic tests for serial correlation, functional normality, and heteroskedastic specification error were carried out to verify the ARDL model\'s goodness of fit. Additionally, the cumulative sum of recursive (CUSUM) and cumulative sum of squares of recursive residuals (CUSUMSQ) were used to test model stability. Results The results indicate that in the long run, an increase in public spending of one percent significantly reduces malaria incidence by 0.196 at the 10 percent level of significance. On the other hand, there is no significant evidence of private health expenditure\'s effect on malaria incidence. However, in the short run, public spending reduces malaria incidence by a smaller magnitude of 0.158 percent relative to the long-run. Still, private expenditure is found to exhibit no significant effect. Additional findings point to the importance of GDP per capita and urban population growth in reducing malaria incidence, whereas female unemployment, income inequality, as well as female-headed household. In the short run, however, the female-headed households and urban population growth are found to significantly reduce malaria incidence while an improvement in regulatory quality decreases malaria incidence by 0.129 percent. Conclusions There is need for further government interventions to reduce malaria incidence in the country via budget allocation, as well as the strengthening of programmes to raise household income to support private health spending, in addition to the development of strategies to promote well-planned and organized urban centres.
Læs mere Tjek på PubMedAmerican Journal of Tropical Medicine and Hygiene, 2.05.2024
Tilføjet 2.05.2024
Journal Name: The American Journal of Tropical Medicine and Hygiene Volume: 110 Issue: 5 Pages: 887-891
Læs mere Tjek på PubMedAmerican Journal of Tropical Medicine and Hygiene, 2.05.2024
Tilføjet 2.05.2024
Journal Name: The American Journal of Tropical Medicine and Hygiene Volume: 110 Issue: 5 Pages: 892-901
Læs mere Tjek på PubMedAmerican Journal of Tropical Medicine and Hygiene, 2.05.2024
Tilføjet 2.05.2024
Journal Name: The American Journal of Tropical Medicine and Hygiene Volume: 110 Issue: 5 Pages: 902-909
Læs mere Tjek på PubMedAmerican Journal of Tropical Medicine and Hygiene, 2.05.2024
Tilføjet 2.05.2024
Journal Name: The American Journal of Tropical Medicine and Hygiene Volume: 110 Issue: 5 Pages: 921-924
Læs mere Tjek på PubMedMalaria Journal, 30.04.2024
Tilføjet 30.04.2024
Abstract Background Malaria treatment in sub-Saharan Africa is faced with challenges including unreliable supply of efficacious agents, substandard medicines coupled with high price of artemisinin-based combinations. This affects access to effective treatment increasing risk of malaria parasite resistance development and adverse drug events. This study investigated access to quality-assured artemisinin-based combination therapy (QAACT) medicines among clients of selected private drug-outlets in Uganda. Methods This was a cross sectional study where exit interviews were conducted among clients of private drug outlets in low and high malaria transmission settings in Uganda. This study adapted the World Health Organization/Health Action International (WHO/HAI) standardized criteria. Data was collected using a validated questionnaire. Data entry screen with checks was created in Epi-data ver 4.2 software and data entered in duplicate. Data was transferred to STATA ver 14.0 and cleaned prior to analysis. The analysis was done at 95% level of significance. Results A total of 1114 exit interviews were conducted among systematically sampled drug outlet clients. Over half, 54.9% (611/1114) of the participants were males. Majority, 97.2% (1083/1114) purchased an artemisinin-based combination anti-malarial. Most, 55.5% (618/1114) of the participants had a laboratory diagnosis of malaria. Majority, 77.9% (868/1114) of the participants obtained anti-malarial agents without a prescription. Less than a third, 27.7% (309/1114) of the participants obtained a QAACT. Of the participants who obtained QAACT, more than half 56.9% (173/309) reported finding the medicine expensive. The predictors of accessing a QAACT anti-malarial among drug outlet clients include type of drug outlet visited (aPR = 0.74; 95%CI 0.6, 0.91), not obtaining full dose (3-day treatment) of ACT (aPR = 0.49; 95%CI 0.33, 0.73), not finding the ACT expensive (aPR = 1.24; 95%CI 1.03, 1.49), post-primary education (aPR = 1.29; 95%CI 1.07,1.56), business occupation (aPR = 1.24; 95%CI 1.02,1.50) and not having a prescription (aPR = 0.76; 95%CI 0.63, 0.92). Conclusion Less than a third of the private drug outlet clients obtained a QAACT for management of malaria symptoms. Individuals who did not find artemisinin-based combinations to be expensive were more likely to obtain a QAACT anti-malarial. The Ministry of Health needs to conduct regular surveillance to monitor accessibility of QAACT anti-malarial agents under the current private sector copayment mechanism.
Læs mere Tjek på PubMedMalaria Journal, 30.04.2024
Tilføjet 30.04.2024
Abstract Background The decreasing residual efficacy of insecticides is an important factor when making decisions on insecticide choice for national malaria control programmes. The major challenge to using chemicals for vector control is the selection for the development of insecticide resistance. Since insecticide resistance has been recorded for most of the existing insecticides used for indoor residual spraying, namely, DDT, pyrethroids, organophosphates and carbamates, and new chemicals are necessary for the continued success of indoor residual spraying. The aim of this study was to assess the residual efficacy of Actellic 300CS, SumiShield™ 50WG and Fludora®Fusion by spraying on different wall surfaces. Methods One hundred and sixty-eight houses with different wall surface types (mud, cement, painted cement, and tin) which represented the rural house wall surface types in KwaZulu-Natal, South Africa were used to evaluate the residual efficacy of Actellic 300CS, SumiShield 50WG and Fludora®Fusion with DDT as the positive control. All houses were sprayed by experienced spray operators from the Malaria Control Programme. Efficacy of these insecticides were evaluated by contact bioassays against Anopheles arabiensis, a vector species. The residual efficacy of the insecticide formulations was evaluated against a susceptible insectary-reared population of An. arabiensis using WHO cone bioassays. Results Effectiveness of the three insecticides was observed up to 12 months post-spray. When assessing the achievement of 100% mortality over time, SumiShield performed significantly better than DDT on mud (OR 2.28, 95% CI 1.72–3.04) and painted cement wall types (OR 3.52, 95% CI 2.36–5.26). On cement wall types, Actellic was found to be less effective than DDT (OR 0.55, 95% CI 0.37–0.82) while Fludora®Fusion was less effective on tin wall types (OR 0.67, 95% CI 0.47–0.95). When compared to the combined efficacy of DDT on mud surfaces, SumiShield applied to each of the mud, cement and painted cement wall types and DDT applied to the cement wall types was found to be significantly more effective. These insecticides usually resulted in 100% mortality for up to 12 months with a delayed mortality period of 96–144 h, depending on the insecticide evaluated and the surface type sprayed. Conclusion Field evaluation of these insecticides have shown that Actellic, SumiShield and Fludora®Fusion are suitable replacements for DDT. Each of these insecticides can be used for malaria vector control, requiring just one spray round. These insecticides can be used in rotation or as mosaic spraying.
Læs mere Tjek på PubMedMalaria Journal, 30.04.2024
Tilføjet 30.04.2024
Abstract Introduction Introduction: Malaria continues to be the leading cause of hospitalization and death in Angola, a country in sub- Saharan Africa. In 2023, in the first quarter, 2,744,682 cases were registered, and of these 2,673 patients died due to malaria disease. Previous studies have shown that the ABO blood group can affect the progression of malaria to severe conditions after P. falciparum infection, while the sickle cell gene offers relative protection. Objective We investigated changes in the blood count according to blood groups (ABO/Rh) and sickle cell trait in patients with malaria in Luanda, capital of Angola. Methodology This was a longitudinal, prospective and observational study with 198 patients hospitalized for malaria. Results Of the 198 patients studied, 13(6.6%) were ABRh(+), 4(2.0%) were ARh(-), 49(24.7%) were ARh(+), 42(21, 2%) were BRh (+), 5(2.5%) were ORh(-) and 85(42.9%) were ORh(+). For sickle cell trait, 145(73.2%) were AA, 37(18.7%) were AS and 16(8.1%) were SS. No statistical relationship was observed between age group, sex, parasitemia, clinical picture, hematocrit, MCV, HCM, MCHC, leukocytes, NEUT, LINF and PTL values with blood groups (p0.05). There was no relationship between age, parasitemia, clinical condition, MCV, HCM and MCHC values, leukocytes, NEUT and LINF with sickle cell trait (p0.05). Conclusion It is imperative to differentiate patients with malaria based on blood groups and sickle cell trait, taking into account mainly the blood count parameters that demonstrate that there are patients who, depending on blood group or sickle cell trait, may react weakly to malaria infection regardless of the degree of parasitemia and medical prognosis.
Læs mere Tjek på PubMedMalaria Journal, 29.04.2024
Tilføjet 29.04.2024
Abstract Background Despite efforts made to reduce morbidity and mortality associated with malaria, especially in sub-Saharan Africa, malaria continues to be a public health concern that requires innovative efforts to reach the WHO-set zero malaria agenda. Among the innovations is the use of artemisinin-based combination therapy (ACT) that is effective against Plasmodium falciparum. Generic artemether–lumefantrine (AL) is used to treat uncomplicated malaria after appropriate diagnosis. AL is metabolized by the cytochrome P450 family of enzymes, such as CYP2B6, CYP3A4 and CYP3A5, which can be under pharmacogenetic influence. Pharmacogenetics affecting AL metabolism, significantly influence the overall anti-malarial activity leading to variable therapeutic efficacy. This study focused on generic AL drugs used in malarial treatment as prescribed at health facilities and evaluated pharmacogenomic influences on their efficacy. Methods Patients who have been diagnosed with malaria and confirmed through RDT and microscopy were recruited in this study. Blood samples were taken on days 1, 2, 3 and 7 for parasite count and blood levels of lumefantrine, artemisinin, desbutyl-lumefantrine (DBL), and dihydroartemisinin (DHA), the active metabolites of lumefantrine and artemether, respectively, were analysed using established methods. Pharmacogene variation analysis was undertaken using iPLEX microarray and PCR–RFLP. Results A total of 52 patients completed the study. Median parasite density from day 1 to 7 ranged from 0–2666/μL of blood, with days 3 and 7 recording 0 parasite density. Highest median plasma concentration for lumefantrine and desbutyl lumefantrine, which are the long-acting components of artemisinin-based combinations, was 4123.75 ng/mL and 35.87 ng/mL, respectively. Day 7 plasma lumefantrine concentration across all generic ACT brands was ≥ 200 ng/mL which potentially accounted for the parasitaemia profile observed. Monomorphism was observed for CYP3A4 variants, while there were observed variations in CYP2B6 and CYP3A5 alleles. Among the CYP3A5 genotypes, significant differences in genotypes and plasma concentration for DBL were seen on day 3 between 1/*1 versus *1/*6 (p = 0.002), *1/*3 versus *1/*6 (p = 0.006) and *1/*7 versus *1/*6 (p = 0.008). Day 7 plasma DBL concentrations showed a significant difference between *1/*6 and *1/*3 (p = 0.026) expressors. Conclusions The study findings show that CYP2B6 and CYP3A5 pharmacogenetic variations may lead to higher plasma exposure of AL metabolites.
Læs mere Tjek på PubMedMalaria Journal, 28.04.2024
Tilføjet 28.04.2024
Abstract Background Malaria is still a disease of global public health importance and children under-five years of age are the most vulnerable to the disease. Nigeria adopted the “test and treat” strategy in the national malaria guidelines as one of the ways to control malaria transmission. The level of adherence to the guidelines is an important indicator for the success or failure of the country’s roadmap to malaria elimination by 2030. This study aimed to assess the fidelity of implementation of the national guidelines on malaria diagnosis for children under-five years and examine its associated moderating factors in health care facilities in Rivers State, Nigeria. Methods This was a descriptive, cross-sectional study conducted in Port Harcourt metropolis. Data were collected from 147 public, formal private and informal private health care facilities. The study used a questionnaire developed based on Carroll’s Conceptual Framework for Implementation Fidelity. Frequency, mean and median scores for implementation fidelity and its associated factors were calculated. Associations between fidelity and the measured predictors were examined using Mann Whitney U test, Kruskal Wallis test, and multiple linear regression modelling using robust estimation of errors. Regression results are presented in adjusted coefficient (β) and 95% confidence intervals. Results The median (IQR) score fidelity score for all participants was 65% (43.3, 85). Informal private facilities (proprietary patent medicine vendors) had the lowest fidelity scores (47%) compared to formal private (69%) and public health facilities (79%). Intervention complexity had a statistically significant inverse relationship to implementation fidelity (β = − 1.89 [− 3.42, − 0.34]). Increase in participant responsiveness (β = 8.57 [4.83, 12.32]) and the type of malaria test offered at the facility (e.g., RDT vs. no test, β = 16.90 [6.78, 27.03]; microscopy vs. no test, β = 21.88 [13.60, 30.16]) were positively associated with fidelity score. Conclusions This study showed that core elements of the “test and treat” strategy, such as testing all suspected cases with approved diagnostic methods before treatment, are still not fully implemented by health facilities. There is a need for strategies to increase fidelity, especially in the informal private health sector, for malaria elimination programme outcomes to be achieved.
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