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Malaria Journal, 17.10.2024
Tilføjet 17.10.2024
Abstract Background Malaria in pregnancy (MiP) is a public health concern especially for pregnant women living in slums. The World Health Organization recommends at least three doses of Sulfadoxine-Pyrimethamine (SP) to prevent MiP. In Ghana, it is recommended that pregnant women receive a minimum of five doses of the medication. This study sought to determine the level of adherence to IPT5 policy and factors associated with adherence among pregnant women in a slum community in Ghana. Methods This was a cross-sectional study involving 232 nursing mothers and four healthcare workers at the St. Martin’s Memorial Hospital, Sukura, Ghana. Sociodemographic characteristics of nursing mothers were obtained using an interview-administered questionnaire. Data on the number of SP doses and other obstetrics characteristics were collected by reviewing the antenatal record books. To obtain information about healthcare and health system factors associated with adherence to the five-dose policy, four healthcare providers were interviewed. A data extraction form was used to obtain information about the availability of SP at the facility. Results The level of adherence to IPT5 was 8.6% (20/232) (95% CI 5.0–12.3) among the participants. Only 8.4% of the participants received their first dose at 16 weeks. Respondents who began ANC in the second trimester were 81% less likely to adhere to IPT5 than those who began in the first trimester (aOR = 0.19, 95% CI 90.01–0.65, p
Læs mere Tjek på PubMedBMC Infectious Diseases, 17.10.2024
Tilføjet 17.10.2024
Abstract Background Malaria remains a significant public health concern, especially for the deadliest parasite, Plasmodium falciparum. During acute malaria, various cytokines, including osteopontin (OPN), regulate the immune response. OPN has been shown to be protective against malaria in mice. Nonetheless, its precise function and potential ability to control parasites during acute malaria in humans remain poorly understood. Results Blood samples were collected from Swedish adults with imported malaria, Ugandan children and adults with symptomatic malaria (including follow-up after 42 days), Ugandans with non-malarial fever and healthy individuals from both Uganda and Sweden. Parasitemia was determined by microscopy. Malaria-negative samples were verified by LAMP. OPN and interferon-γ (IFN- γ) levels were measured using ELISA. In children, OPN levels were significantly higher during acute infection compared to levels after 42 days, whereas Ugandan adults showed no difference. Swedish adults with imported malaria had elevated OPN levels compared to both Swedish controls and Ugandan adults with malaria. Parasitemia was significantly correlated with both OPN and IFN-γ levels across the entire cohort. While a significant correlation between OPN and IFN-γ was evident overall, it remained statistically significant only in Ugandan adults when analyzed by subgroups. This suggests that OPN is not just a general marker of inflammation but may be regulated differently during the development of malaria immunity. Conclusions In acute malaria, elevated OPN levels showed a stronger correlation with lack of immunity than age. These findings underscore the potential importance of OPN in malaria, particularly in non-immune individuals.
Læs mere Tjek på PubMedJulia Zerebinski, David F. Plaza
Trends in Parasitology, 17.10.2024
Tilføjet 17.10.2024
Recent studies by Girgis et al. and de Cesare et al. promise to advance malaria genomic surveillance using inexpensive and portable long-read amplicon-sequencing technologies. These technologies allow rapid characterization of drug-resistance markers, antigenic diversity, and diagnostic target loci from dried blood spots, providing new tools for surveillance in endemic regions and informing interventions to combat malaria more effectively.
Læs mere Tjek på PubMedRitwik Singhal, Isadora O. Prata, Victoria A. Bonnell, Manuel Llinás
Trends in Parasitology, 17.10.2024
Tilføjet 17.10.2024
The regulation of gene expression in Plasmodium spp., the causative agents of malaria, relies on precise transcriptional control. Malaria parasites encode a limited repertoire of sequence-specific transcriptional regulators dominated by the apicomplexan APETALA 2 (ApiAP2) protein family. ApiAP2 DNA-binding proteins play critical roles at all stages of the parasite life cycle. Recent studies have provided mechanistic insight into the functional roles of many ApiAP2 proteins. Two major areas that have advanced significantly are the identification of ApiAP2-containing protein complexes and the role of ApiAP2 proteins in malaria parasite sexual development. In this review, we present recent advances on the functional biology of ApiAP2 proteins and their role in regulating gene expression across the blood stages of the parasite life cycle.
Læs mere Tjek på PubMedMalaria Journal, 16.10.2024
Tilføjet 16.10.2024
Abstract Background Non-inferiority trials are recommended by the World Health Organization (WHO) to demonstrate that health products show comparable efficacy to that of existing standard of care. As part of the WHO Global Malaria Programme (GMP) process of assessment of malaria vector control products, a second-in-class insecticide-treated net (ITN) must be shown to be non-inferior to a first-in-class product based on mosquito mortality. The public health impact of the first-in-class pyrethroid-piperonyl butoxide (PBO) ITN, Olyset® Plus, has been demonstrated in epidemiological trials in areas with insecticide-resistant mosquitoes, but there is a need to determine the efficacy of other pyrethroid-PBO nets to ensure timely market availability of nets in order to increase access to ITNs. The non-inferiority of a deltamethrin-PBO ITN Yorkool® G3 was evaluated entomologically against Olyset® Plus in experimental huts in Tanzania, following WHO guidelines for non-inferiority trials. Methods The trial of the two pyrethroid-PBO ITNs was conducted in experimental huts in Lupiro, Tanzania, using a randomized 7 × 7 Latin square block design. The study ran for 49 nights in 14 huts assessing the mosquito mortality and blood-feeding of wild, free-flying, pyrethroid-resistant Anopheles arabiensis. Using the non-inferiority approach, the comparative efficacy (primary endpoint was mosquito mortality at 24 h and secondary endpoint was blood-feeding) of unwashed and 20 times field-washed pyrethroid-PBO Yorkool® G3 ITNs, were compared with the first-in-class product Olyset® Plus and against a pyrethroid-only ITN, PermaNet® 2.0 ITNs, as a standard comparator. Results The experimental hut trial demonstrated non-inferiority and superiority of Yorkool® G3 to Olyset® Plus based on mosquito mortality [51% vs. 39%, OR 1.68 (95% CI 1.50–1.88)], given that lower 95% CI exceeded 0.74 (delta of 39%) and the margin of no difference (1). Blood-feeding inhibition was high for all treated ITNs (> 90%) and Yorkool® G3 was non-inferior to Olyset® Plus [4% vs. 2%, OR 1.81 (95% CI 1.46–2.39)], given that upper 95% CI was less than 4.85 (delta of 4%). The pyrethroid-PBO ITNs were superior to the pyrethroid-only net, PermaNet® 2.0, as determined by both the proportion of mortality and blood-feeding of mosquitoes (p-value
Læs mere Tjek på PubMedBMC Infectious Diseases, 16.10.2024
Tilføjet 16.10.2024
Abstract Background Malaria remains a significant public health concern, especially for the deadliest parasite, Plasmodium falciparum. During acute malaria, various cytokines, including osteopontin (OPN), regulate the immune response. OPN has been shown to be protective against malaria in mice. Nonetheless, its precise function and potential ability to control parasites during acute malaria in humans remain poorly understood. Results Blood samples were collected from Swedish adults with imported malaria, Ugandan children and adults with symptomatic malaria (including follow-up after 42 days), Ugandans with non-malarial fever and healthy individuals from both Uganda and Sweden. Parasitemia was determined by microscopy. Malaria-negative samples were verified by LAMP. OPN and interferon-γ (IFN- γ) levels were measured using ELISA. In children, OPN levels were significantly higher during acute infection compared to levels after 42 days, whereas Ugandan adults showed no difference. Swedish adults with imported malaria had elevated OPN levels compared to both Swedish controls and Ugandan adults with malaria. Parasitemia was significantly correlated with both OPN and IFN-γ levels across the entire cohort. While a significant correlation between OPN and IFN-γ was evident overall, it remained statistically significant only in Ugandan adults when analyzed by subgroups. This suggests that OPN is not just a general marker of inflammation but may be regulated differently during the development of malaria immunity. Conclusions In acute malaria, elevated OPN levels showed a stronger correlation with lack of immunity than age. These findings underscore the potential importance of OPN in malaria, particularly in non-immune individuals.
Læs mere Tjek på PubMedN. J. WhiteK. Chotivanich1Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand2Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom3Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, ThailandFerric C. FangSunil Parikh
Clinical Microbiology Reviews, 16.10.2024
Tilføjet 16.10.2024
Malaria Journal, 16.10.2024
Tilføjet 16.10.2024
Abstract Malaria parasites are haploid within humans, but infections often contain genetically distinct groups of clonal parasites. When the per-infection number of genetically distinct clones (i.e., the multiplicity of infection, MOI) exceeds one, and per-infection genetic data are generated in bulk, important information are obfuscated. For example, the MOI, the phases of the haploid genotypes of genetically distinct clones (i.e., how the alleles concatenate into sequences), and their frequencies. This complicates many downstream analyses, including relatedness estimation. MOIs, parasite sequences, their frequencies, and degrees of relatedness are used ubiquitously in malaria studies: for example, to monitor anti-malarial drug resistance and to track changes in transmission. In this article, MrsFreqPhase methods designed to estimate statistically malaria parasite MOI, relatedness, frequency and phase are reviewed. An overview, a historical account of the literature, and a statistical description of contemporary software is provided for each method class. The article ends with a look towards future method development, needed to make best use of new data types generated by cutting-edge malaria studies reliant on MrsFreqPhase methods.
Læs mere Tjek på PubMedMalaria Journal, 16.10.2024
Tilføjet 16.10.2024
Abstract Background Healthcare providers (HCPs) practice and correct management of suspected malaria (CMSM) are central components of malaria elimination and prevention of re-establishment (POR) in countries in the elimination phase. However, knowledge of malaria surveillance systems and HCPs practices often wanes in countries aiming to eliminate malaria due to the low numbers of cases. The study aimed to implement a valid Simulated Malaria Online Tool (SMOT) for assessment HCP performance in CMSM and POR in a malaria-free area. Methods HCPs were evaluated using SMOT tool based on four criteria including presenting a suspected malaria case for detection of HCPs’ failures in recognition (a), diagnosis (b), appropriate treatment (c), and urgent reporting (d); and compared with simulated patients (SP). Multiple logistic regression analysis was carried out to estimate adjusted odds ratios (ORs) for the risk of HCPs failures. Results The overall failure proportion was 237 (83%), and the majority of failures were in recognition (a). There was no significant difference between the SMOT and SP based on all failure criteria (P > 0.05). The private clinic (93%) and the public specialized clinic (70%) had the highest and lowest failure proportions. After passing the recognition stage (a), the overall failure proportions decreased to 47.8% and 25.0% for total HCPs and infectious disease specialists, respectively. In the final analysis, private sector (AOR = 4.36: 1.25–15.2), not-specialist providers (AOR = 2.84: 1.29–6.25) and HCPs with ≥ 5 years’ experience (AOR = 2.03: 1.01–6.25) increased the risk of failure. Conclusion Findings confirmed the implementation of SMOT tool in settings where malaria transmission is low or interrupted. The tool is able to identify sub-groups of providers needing strengthening, and contributes to the prevention of malaria re-establishment.
Læs mere Tjek på PubMedJournal of the American Medical Association, 15.10.2024
Tilføjet 15.10.2024
Journal of the American Medical Association, 15.10.2024
Tilføjet 15.10.2024
This quasi-experimental study evaluates the association between the distribution of rapid diagnostic tests for malaria and the management of febrile illness and mortality among children younger than 5 years of age in sub-Saharan African countries.
Læs mere Tjek på PubMedBMC Infectious Diseases, 12.10.2024
Tilføjet 12.10.2024
Abstract Background Human Immunodeficiency Virus (HIV) and malaria are two major diseases in sub-Saharan Africa. Co-infection can significantly impact the clinical outcomes of both conditions. We assessed the proportion of HIV-infected children at Korle Bu Teaching Hospital (KBTH) and Princess Marie Louise Hospital (PML) with malaria parasites. The association between asymptomatic malaria parasitaemia and virological non-suppression was also determined in these children. Methods This cross-sectional study of 277 asymptomatic malaria in children receiving care at paediatric HIV clinics at KBTH and PML was conducted from September to November 2022. Patients who had been on antiretroviral therapy (ART) for at least six months were eligible to participate. Structured questionnaires were used to collect socio-demographic information, malaria prevention behaviors, and ART-related data using in-person interviews. Microscopy and PCR were used to screen for malaria, and GeneXpert was used to determine viral load. To examine the determinants of malaria PCR positivity and virological non-suppression, chi-square tests and logistic regression were performed. Results The median age of the participants was 9 years (range: 6–12 years). Males comprised 158 (57%) of the study population. We detected 10 (3.6%) and 21 (7.6%) malaria cases by microscopy and PCR, respectively. Virological non-suppression (VL > 1000 copies/ml) was observed in 82 (29.6%) of the 277 participants. Among the suppressed individuals, 62 (22.4%) exhibited low-level viraemia (VL level 40-1000 copies/ml) and 133 (48%) had undetectable viral load levels. No factors were associated with the presence of malaria PCR positivity carriage. Poor adherence to ART was associated with a five-fold increase in the risk of viral load non-suppression (AOR = 4.89 [CI = 2.00-11.98], p = 0.001). Conclusion The proportion of children living with HIV with asymptomatic malaria parasitaemia was low. Approximately one-third of the study population had virological non-suppression. The interaction between malaria parasitemia and viral replication may not be the main cause for virological non-suppression in this low transmission area.
Læs mere Tjek på PubMedPaula Tesine, Sze-Ann Woon, Moses Laman, Gumul Yadi, Phantica Yambo, Bernadine Kasian, Lina Lorry, Leanne J. Robinson, Sam Salman, Kevin T. Batty, William Pomat, Laurens Manning, Wendy A. Davis, Timothy M.E. Davis, Brioni R Moore
International Journal of Infectious Diseases, 12.10.2024
Tilføjet 12.10.2024
A range of management strategies have been developed to counter the adverse maternal and foetal outcomes associated with malaria in pregnancy [1]. These include prompt treatment of symptomatic infections, and intermittent preventive treatment in pregnancy (IPTp) which commonly comprises monthly sulfadoxine-pyrimethamine [2]. Optimal postpartum management is, however, less clear despite epidemiological evidence that women in endemic areas remain vulnerable after delivery. The overall risk of malaria declines during the postpartum period but several studies have shown it does not reach that of non-pregnant women from the same community [3-5], while the incidence of vivax malaria during this period may be higher than that during pregnancy [6].
Læs mere Tjek på PubMedMalaria Journal, 11.10.2024
Tilføjet 11.10.2024
Abstract Climatic conditions are a key determinant of malaria transmission intensity, through their impacts on both the parasite and its mosquito vectors. Mathematical models relating climatic conditions to malaria transmission can be used to develop spatial maps of climatic suitability for malaria. These maps underpin efforts to quantify the distribution and burden of malaria in humans, enabling improved monitoring and control. Previous work has developed mathematical models and global maps for the suitability of temperature for malaria transmission. In this paper, existing temperature-based models are extended to include two other important bioclimatic factors: humidity and rainfall. This model is combined with fine spatial resolution climatic data to produce a more biologically-realistic global map of climatic suitability for Plasmodium falciparum malaria. The climatic suitability index developed corresponds more closely than previous temperature suitability indices with the global distribution of P. falciparum malaria. There is weak agreement between the Malaria Atlas Project estimates of P. falciparum prevalence in Africa and the estimates of suitability solely based on temperature (Spearman Correlation coefficient of (rho = 0.24) ). The addition of humidity and then rainfall improves the comparison ( (rho = 0.62) when humidity added; (rho =0.70) when both humidity and rainfall added). By incorporating the impacts of humidity and rainfall, this model identifies arid regions that are not climatically suitable for transmission of P. falciparum malaria. Incorporation of this improved index of climatic suitability into geospatial models can improve global estimates of malaria prevalence and transmission intensity.
Læs mere Tjek på PubMedMalaria Journal, 11.10.2024
Tilføjet 11.10.2024
Abstract Climatic conditions are a key determinant of malaria transmission intensity, through their impacts on both the parasite and its mosquito vectors. Mathematical models relating climatic conditions to malaria transmission can be used to develop spatial maps of climatic suitability for malaria. These maps underpin efforts to quantify the distribution and burden of malaria in humans, enabling improved monitoring and control. Previous work has developed mathematical models and global maps for the suitability of temperature for malaria transmission. In this paper, existing temperature-based models are extended to include two other important bioclimatic factors: humidity and rainfall. This model is combined with fine spatial resolution climatic data to produce a more biologically-realistic global map of climatic suitability for Plasmodium falciparum malaria. The climatic suitability index developed corresponds more closely than previous temperature suitability indices with the global distribution of P. falciparum malaria. There is weak agreement between the Malaria Atlas Project estimates of P. falciparum prevalence in Africa and the estimates of suitability solely based on temperature (Spearman Correlation coefficient of (rho = 0.24) ). The addition of humidity and then rainfall improves the comparison ( (rho = 0.62) when humidity added; (rho =0.70) when both humidity and rainfall added). By incorporating the impacts of humidity and rainfall, this model identifies arid regions that are not climatically suitable for transmission of P. falciparum malaria. Incorporation of this improved index of climatic suitability into geospatial models can improve global estimates of malaria prevalence and transmission intensity.
Læs mere Tjek på PubMedMalaria Journal, 11.10.2024
Tilføjet 11.10.2024
Abstract Background The RTS,S malaria vaccine has been prequalified for use in endemic settings prioritizing areas with moderate to high disease transmission. The impact of a vaccine at the population level may differ from observations during clinical trial due to programmatic, and individual-related factors, among others. The objective of this study was to assess the impact of the RTS,S malaria vaccine on uncomplicated malaria among children aged 12–59 months in the Phase IV study districts, Upper East Region, Ghana. Methods A retrospective study was conducted using routine malaria surveillance data for the period 2020–2022. The burden of uncomplicated malaria was compared between the implementing (Kasena Nankana East and West districts) and comparator areas (Builsa North and South districts). The impact of RTS,S malaria vaccine was assessed by estimating the percentage reduction in uncomplicated malaria and incidence averted in the implementing area, accounting for the effect of confounders. Results Over 50,000 episodes of uncomplicated malaria among children aged 12–59 months were included in the study. Uncomplicated malaria was reduced by 33% (95%CI 29–36) over the entire study period, but the malaria incidence averted declined from 324/1,000 (95% CI 298–339; p
Læs mere Tjek på PubMedMalaria Journal, 11.10.2024
Tilføjet 11.10.2024
Abstract Background The RTS,S malaria vaccine has been prequalified for use in endemic settings prioritizing areas with moderate to high disease transmission. The impact of a vaccine at the population level may differ from observations during clinical trial due to programmatic, and individual-related factors, among others. The objective of this study was to assess the impact of the RTS,S malaria vaccine on uncomplicated malaria among children aged 12–59 months in the Phase IV study districts, Upper East Region, Ghana. Methods A retrospective study was conducted using routine malaria surveillance data for the period 2020–2022. The burden of uncomplicated malaria was compared between the implementing (Kasena Nankana East and West districts) and comparator areas (Builsa North and South districts). The impact of RTS,S malaria vaccine was assessed by estimating the percentage reduction in uncomplicated malaria and incidence averted in the implementing area, accounting for the effect of confounders. Results Over 50,000 episodes of uncomplicated malaria among children aged 12–59 months were included in the study. Uncomplicated malaria was reduced by 33% (95%CI 29–36) over the entire study period, but the malaria incidence averted declined from 324/1,000 (95% CI 298–339; p
Læs mere Tjek på PubMedMalaria Journal, 11.10.2024
Tilføjet 11.10.2024
Abstract Background Malaria prevention and control strategies have been hampered by urbanization and the spread of Anopheles stephensi. The spread of this vector into Africa further complicates the already complex malaria situation, that could put about 126 million Africans at risk of infection. Hence, this study aimed to assess the determinants of urban malaria, focusing on the role of urbanization and the distribution of An. stephensi in Eastern Ethiopia. Methods A matched case control study was conducted among febrile urban residents of Dire Dawa (malaria positive as cases and negative as a control). A capillary blood sample was collected for parasite identification using microscopic examination and an interviewer administered questionnaire was used to collect additional data. Centers for Disease Control and Prevention miniature light traps (CDC-LT) and Prokopack aspirator were used to collect adult mosquito vectors from the selected cases and control houses to identify the mosquito vector species. Then, the data were exported to STATA for analysis. Conditional logistic regression was done to identify determinants, and principal component Analysis (PCA) was done for some independent variables. Results This study enrolled 132 cases and 264 controls from urban setting only. Of the 132 cases, 90 cases were positive for Plasmodium falciparum, 34 were positive for Plasmodium vivax and 8 had mixed infections. All cases and controls were similar with regard to their respective age and sex. Travel history (AOR: 13.1, 95% CI 2.8–61.4), presence of eves and holes on walls (AOR: 2.84, 95% CI 1.5–5.5), history of malaria diagnosis (AOR: 2.4, 95% CI 1.1–5.3), owning any livestock (AOR: 7.5, 95% CI 2.4–22.8), presence of stagnant water in the area (AOR: 3.2, 95% CI 1.7–6.1), sleeping under bed net the previous night (AOR: 0.21, 95% CI 0.1–0.6) and knowledge on malaria and its prevention (AOR: 2.2, 95% CI 1.2–4.1) were determinants of urban malaria infection. About 34 adult Anopheles mosquitoes were collected and identified from those selected cases and control houses and 27 of them were identified as An. stephensi. Conclusion Among the cases, the dominant species were P. falciparum. This study identified travel history, house condition, past infection, livestock ownership, stagnant water, bed net use, and malaria knowledge as determinants of infection. This study also found the dominance of the presence of An. stephensi among the collected mosquito vectors. This suggests that the spread of An. stephensi may be impacting malaria infection in the study area. Hence, strengthening urban-targeted malaria interventions should be enhanced to prevent and control further urban malaria infection and spread.
Læs mere Tjek på PubMedMalaria Journal, 11.10.2024
Tilføjet 11.10.2024
Abstract Background Malaria prevention and control strategies have been hampered by urbanization and the spread of Anopheles stephensi. The spread of this vector into Africa further complicates the already complex malaria situation, that could put about 126 million Africans at risk of infection. Hence, this study aimed to assess the determinants of urban malaria, focusing on the role of urbanization and the distribution of An. stephensi in Eastern Ethiopia. Methods A matched case control study was conducted among febrile urban residents of Dire Dawa (malaria positive as cases and negative as a control). A capillary blood sample was collected for parasite identification using microscopic examination and an interviewer administered questionnaire was used to collect additional data. Centers for Disease Control and Prevention miniature light traps (CDC-LT) and Prokopack aspirator were used to collect adult mosquito vectors from the selected cases and control houses to identify the mosquito vector species. Then, the data were exported to STATA for analysis. Conditional logistic regression was done to identify determinants, and principal component Analysis (PCA) was done for some independent variables. Results This study enrolled 132 cases and 264 controls from urban setting only. Of the 132 cases, 90 cases were positive for Plasmodium falciparum, 34 were positive for Plasmodium vivax and 8 had mixed infections. All cases and controls were similar with regard to their respective age and sex. Travel history (AOR: 13.1, 95% CI 2.8–61.4), presence of eves and holes on walls (AOR: 2.84, 95% CI 1.5–5.5), history of malaria diagnosis (AOR: 2.4, 95% CI 1.1–5.3), owning any livestock (AOR: 7.5, 95% CI 2.4–22.8), presence of stagnant water in the area (AOR: 3.2, 95% CI 1.7–6.1), sleeping under bed net the previous night (AOR: 0.21, 95% CI 0.1–0.6) and knowledge on malaria and its prevention (AOR: 2.2, 95% CI 1.2–4.1) were determinants of urban malaria infection. About 34 adult Anopheles mosquitoes were collected and identified from those selected cases and control houses and 27 of them were identified as An. stephensi. Conclusion Among the cases, the dominant species were P. falciparum. This study identified travel history, house condition, past infection, livestock ownership, stagnant water, bed net use, and malaria knowledge as determinants of infection. This study also found the dominance of the presence of An. stephensi among the collected mosquito vectors. This suggests that the spread of An. stephensi may be impacting malaria infection in the study area. Hence, strengthening urban-targeted malaria interventions should be enhanced to prevent and control further urban malaria infection and spread.
Læs mere Tjek på PubMedMalaria Journal, 11.10.2024
Tilføjet 11.10.2024
Abstract Background Malaria affects children under the age of five and pregnant women, leading to high morbidity and mortality rates. In sub-Saharan Africa, Patent and Proprietary Medicine Vendors (PPMVs) have been identified as key players in the provision of malaria treatment due to their accessibility and availability in communities, but PPMVs are not usually tested before fever cases are treated as malaria or refer clients. The aim of this study was to explore the factors influencing caregivers’ acceptance of the test, treatment and referral practices for malaria management provided by CPs and PPMVs in Kaduna and Lagos states, Nigeria. Methods A cross-sectional quantitative telephone survey was conducted among 150 caregivers of children under five years old who received malaria services from trained CPs and PPMVs between May and July 2022. Descriptive and bivariate analyses were performed to identify factors significantly associated with the acceptability of malaria management services. All statistically significant factors from the bivariate analysis were explored using logistic regression models, and odds ratios (ORs) with confidence intervals (CIs) were calculated to predict acceptability. The 95% level was used to define statistically significant associations (p ≤ 0.05). Results All caregivers were asked questions that aided in obtaining a diagnosis of malaria. More than two-thirds of the caregivers (68%) reported that the child was tested by a CP/PPMV. Among those treated (148), 89% reported that the child was administered artemisinin combination therapy (ACT) irrespective of whether the child tested positive or negative for malaria. At the bivariate level, acceptability was greater among caregivers of children aged 13 months and older than among caregivers of children aged 0–12 months (93% vs. 76%, p = 0.004). Caregivers of children who prescribed ACT had greater acceptance than did those not prescribing ACT (92% vs. 69%, p = 0.010). Multivariate analysis revealed that these relationships held. Conclusions The adoption of the test, treat, and refer practice as a standard approach by CPs and PPMVs could replace the widespread practice of prescribing medications without conducting tests. This shift has the potential to improve the quality of malaria management services and enhance patient outcomes.
Læs mere Tjek på PubMedMalaria Journal, 11.10.2024
Tilføjet 11.10.2024
Abstract Background Malaria affects children under the age of five and pregnant women, leading to high morbidity and mortality rates. In sub-Saharan Africa, Patent and Proprietary Medicine Vendors (PPMVs) have been identified as key players in the provision of malaria treatment due to their accessibility and availability in communities, but PPMVs are not usually tested before fever cases are treated as malaria or refer clients. The aim of this study was to explore the factors influencing caregivers’ acceptance of the test, treatment and referral practices for malaria management provided by CPs and PPMVs in Kaduna and Lagos states, Nigeria. Methods A cross-sectional quantitative telephone survey was conducted among 150 caregivers of children under five years old who received malaria services from trained CPs and PPMVs between May and July 2022. Descriptive and bivariate analyses were performed to identify factors significantly associated with the acceptability of malaria management services. All statistically significant factors from the bivariate analysis were explored using logistic regression models, and odds ratios (ORs) with confidence intervals (CIs) were calculated to predict acceptability. The 95% level was used to define statistically significant associations (p ≤ 0.05). Results All caregivers were asked questions that aided in obtaining a diagnosis of malaria. More than two-thirds of the caregivers (68%) reported that the child was tested by a CP/PPMV. Among those treated (148), 89% reported that the child was administered artemisinin combination therapy (ACT) irrespective of whether the child tested positive or negative for malaria. At the bivariate level, acceptability was greater among caregivers of children aged 13 months and older than among caregivers of children aged 0–12 months (93% vs. 76%, p = 0.004). Caregivers of children who prescribed ACT had greater acceptance than did those not prescribing ACT (92% vs. 69%, p = 0.010). Multivariate analysis revealed that these relationships held. Conclusions The adoption of the test, treat, and refer practice as a standard approach by CPs and PPMVs could replace the widespread practice of prescribing medications without conducting tests. This shift has the potential to improve the quality of malaria management services and enhance patient outcomes.
Læs mere Tjek på PubMedYukiko Miyazaki, Shinya Miyazaki
Trends in Parasitology, 10.10.2024
Tilføjet 10.10.2024
The human malaria parasite Plasmodium falciparum causes the most severe form of malaria in endemic regions and is transmitted via mosquito bites. To better understand the biology of this deadly pathogen, a variety of P. falciparum reporter lines have been generated using transgenic approaches to express reporter proteins, such as fluorescent proteins and luciferases. This review discusses the advances in recently generated P. falciparum transgenic reporter lines, which will aid in the investigation of parasite physiology and the discovery of novel antimalarial drugs. Future prospects for the generation of new and superior human malaria parasite reporter lines are also discussed, and unresolved questions in malaria biology are highlighted to help boost support for the development and implementation of malaria treatments.
Læs mere Tjek på PubMedArega Tsegaye, Assalif Demissew, Ashenafi Abossie, Hallelujah Getachew, Kassahun Habtamu, Teshome Degefa, Xiaoming Wang, Ming-Chieh Lee, Daibin Zhong, James W. Kazura, Guiyun Yan, Delenasaw Yewhalaw
PLoS One Infectious Diseases, 10.10.2024
Tilføjet 10.10.2024
by Arega Tsegaye, Assalif Demissew, Ashenafi Abossie, Hallelujah Getachew, Kassahun Habtamu, Teshome Degefa, Xiaoming Wang, Ming-Chieh Lee, Daibin Zhong, James W. Kazura, Guiyun Yan, Delenasaw Yewhalaw Background Thioester-containing protein 1 (TEP1) is a crucial component of mosquitoes’ natural resistance to parasites. To effectively combat malaria, there is a need to better understand how TEP1 polymorphism affects phenotypic traits during infections. Therefore, the purpose of this study was to determine the Tep1 genotype frequency in malaria vector populations from south-western Ethiopia and investigate its effect on Plasmodium oocyst development in Anopheles arabiensis populations. Methods Using standard dippers, Anopheles mosquito larvae were collected from aquatic habitats in Asendabo, Arjo Dedessa, and Gambella in 2019 and 2020. Collected larvae were reared to adults and identified morphologically. Female An. gambiae s.l. were allowed to feed on infected blood containing the same number of gametocytes obtained from P. falciparum and P. vivax gametocyte-positive individuals using indirect membrane feeding methods. Polymerase Chain Reaction (PCR) was used to identify An. gambiae s.l. sibling species. Three hundred thirty An. gambiae s.l. were genotyped using Restricted Fragment Length Polymorphism (RFLP) PCR and sub samples were sequenced to validate the TEP1 genotyping. Results Among the 330 samples genotyped, two TEP1 alleles, TEP1*S1 (82% frequency) and TEP1*R1 (18% frequency), were identified. Three equivalent genotypes, TEP1*S1/S1, TEP1*R1/R1, and TEP1*S1/R1, had mean frequencies of 65.15%, 2.12%, and 32.73%, respectively. The nucleotide diversity was ranging from 0.36554 to 0. 46751 while haplotype diversity ranged from 0.48871 to 0.63161, across all loci. All sample sites had positive Tajima’s D and Fu’s Fs values. There was a significant difference in the TEP1 allele frequency and genotype frequency among mosquito populations (p < 0.05), except populations of Anopheles arabiensis from Asendabo and Gambella (p > 0.05). In addition, mosquitoes with the TEP1 *RR genotype were susceptible and produced fewer Plasmodium oocysts than mosquitoes with the TEP1 *SR and TEP1 *SS genotypes. Conclusion The alleles identified in populations of An. arabiensis were TEP1*R1 and TEP1*S1. There was no significant variation in TEP1*R1 allele frequency between the high and low transmission areas. Furthermore, An. arabiensis carrying the TEP1*R1 allele was susceptible to Plasmodium infection. Further studies on vector-parasite interactions, particularly on the TEP1 gene, are required for vector control techniques.
Læs mere Tjek på PubMedMalaria Journal, 10.10.2024
Tilføjet 10.10.2024
Abstract Background Malaria is one of the world’s most lethal vector-borne diseases, causing significant health burdens in endemic countries. Several studies on the prevalence of malaria among pregnant women in Ghana have been conducted in various parts of the country, yielding evidence pointing to intra- and inter-regional variations. The current study assessed the prevalence, risk factors, and sociodemographic predictors of malaria among pregnant women in the Bono East Region of Ghana. Methods This multicentre hospital-based study employed a mixed-method cross-sectional design. A multistage sampling technique was used to select seven health facilities and recruited 1452 pregnant women who attended ANC at seven selected health facilities. Haematological examination, a structured closed-ended questionnaire, in-depth interviews (IDIs), and focus group discussions (FGDs) were used to obtain relevant data. Quantitative data were analysed with STATA 14 (StataCorp, College Station, USA). Likewise, the four-step thematic analysis was used to analyse qualitative data. A significant level was set at (p
Læs mere Tjek på PubMedMalaria Journal, 10.10.2024
Tilføjet 10.10.2024
Abstract Background Vector-borne diseases, such as malaria, pose a significant global threat, and climatological factors greatly influence their intensity. Tropical countries, like India, are particularly vulnerable to such diseases, making accurate estimation of malaria risk crucial. Methods This study utilized the well-known Vector-borne Disease Community Model, VECTRI, developed by the International Centre for Theoretical Physics in Trieste. The model was implemented to estimate malaria’s Entomological Inoculation Rate (EIR). Future climatic prediction datasets, including CMIP 5 and population data sets, were used as inputs for the analysis. Three RCP scenarios are considered (Representative Concentration Pathways are climate change scenarios that project radiative forcing to 2100 due to future greenhouse gas concentrations). The projections covered the period from 1 Jan, 2020, to 31 Dec, 2029. Results The estimated mean EIR for the years 2020–2029 ranged, and a significant decline in malaria risk was observed with all RCP 2.6, 4.5, and 8.5 scenarios. Each year 0.3 to 2.6 [min–max] EIR/person/day decline is observed with a strong decline in man rainfall ranging from 5 to 17 [min–max] mm/year and associated high temperatures ranging from 0.03 to 0.06 [min–max] °C/year. During the post-monsoon period, August to November were identified as highly prone to malaria transmission. Spatial analysis revealed that the east coast of India faced a higher vulnerability to malaria risk, which kept increasing through RCP scenarios. Thus, it is essential to exercise caution, especially in areas with heavy rainfall. Conclusion This research provides valuable insights for policy-makers, highlighting the need to implement future strategies to mitigate malaria risk effectively. By utilizing these findings, appropriate measures can be taken to combat the threat posed by malaria and protect public health.
Læs mere Tjek på PubMedMalaria Journal, 10.10.2024
Tilføjet 10.10.2024
Abstract Background Plasmodium vivax is the second most common malaria parasite in Ethiopia. It has been treated with chloroquine (CQ) for the past seven decades. However, the emergence of CQ-resistant strains in the nation urged the Federal Ministry of Health of Ethiopia to review its national malaria treatment guideline in 2018. In the revised guideline, the first-line treatment for uncomplicated P. vivax infection is a combination of CQ and primaquine (PQ). Thus, the present study was designed to evaluate the in vivo efficacy of CQ and PQ combination therapy against clinical P. vivax mono-infection in one of the malaria-endemic areas of Ethiopia. Methods An open-label prospective clinical trial was conducted in the Limmu Kossa District, Jimma zone, Southwest Ethiopia, from September 2023 to March 2024. A total of 108 patients were recruited for the study. All participants received treatment with CQ at a dosage of 25 mg/kg over three days, followed by PQ at 0.25 mg/kg for 14 consecutive days. Patients were monitored for 42 days for any signs of treatment failure and malaria clinical symptoms, as per the World Health Organization (WHO) guidelines for anti-malarial drug evaluation. Additionally, haemoglobin (Hb) levels, body temperature, any adverse events, and signs of haemolysis were assessed. Data was analysed using R-software (version 4.0.0) and a significant level was considered at p
Læs mere Tjek på PubMedLiriye Kurtovic, Gaoqian Feng, Alessia Hysa, Ali Haghiri, Katherine O’Flaherty, Bruce D Wines, Rebeca Santano, Laura D’Andrea, Heidi E Drummer, P Mark Hogarth, Jahit Sacarlal, Freya J I Fowkes, Julie A Simpson, Carlota Dobaño, James G Beeson
Lancet Microbe, 10.10.2024
Tilføjet 10.10.2024
We provide evidence that functional antibody responses mediated by IgG and IgA are associated with protection against malaria in young children vaccinated with RTS,S, and suggest potential differences in the correlates of immunity between males and females. These findings reveal new avenues that could be used to achieve malaria vaccines with higher efficacy.
Læs mere Tjek på PubMedJonathan J Juliano, David J Giesbrecht, Alfred Simkin, Abebe A Fola, Beatus M Lyimo, Dativa Pereus, Catherine Bakari, Rashid A Madebe, Misago D Seth, Celine I Mandara, Zachary R Popkin-Hall, Ramadhan Moshi, Ruth B Mbwambo, Karamoko Niaré, Bronwyn MacInnis, Filbert Francis, Daniel Mbwambo, Issa Garimo, Frank Chacky, Sijenunu Aaron, Abdallah Lusasi, Fabrizio Molteni, Ritha J A Njau, Samwel L Nhiga, Ally Mohamed, Jeffrey A Bailey, Deus S Ishengoma
Lancet Microbe, 10.10.2024
Tilføjet 10.10.2024
These findings show that the k13 Arg561His mutation is common in northwest Tanzania and that multiple emergences of ART-R, similar as to what was seen in southeast Asia, have occurred. Mutations associated with high levels of sulfadoxine–pyrimethamine resistance are common. These results raise concerns about the long-term efficacy of artemisinin and chemoprevention antimalarials in the region. Understanding how multiple emergences interact with drivers of regional spread is essential for combating ART-R in Africa.
Læs mere Tjek på PubMedJournal of the American Medical Association, 9.10.2024
Tilføjet 9.10.2024
An experimental malaria vaccine could offer protection during pregnancy for up to 2 years without a booster dose, according to a randomized clinical trial conducted in Mali. The 3-dose vaccine, known as Plasmodium falciparum sporozoite (PfSPZ) vaccine, had previously been tested successfully in adults in other parts of Africa.
Læs mere Tjek på PubMedBMC Infectious Diseases, 9.10.2024
Tilføjet 9.10.2024
Abstract Background Understanding the level of exposure to Lassa virus (LASV) in at-risk communities allows for the administration of effective preventive interventions to mitigate epidemics of Lassa fever. We assessed the seroprevalence of LASV antibodies in rural and semiurban communities of two cosmopolitan cities in Nigeria with poorly understood Lassa epidemiology. Methods A cross-sectional study was conducted in ten communities located in the Abuja Municipal Area Council (AMAC), Abuja, and Ikorodu Local Government Area (LGA), Lagos, from February 2nd to July 5th, 2022. Serum samples collected from participants were analyzed for IgG and IgM antibodies using a ReLASV® Pan-Lassa NP IgG/IgM enzyme-linked immunosorbent assay (ELISA) kit. A questionnaire administered to participants collected self-reported sociodemographic and LASV exposure information. Seroprevalence of LASV IgG/IgM was estimated overall, and by study site. Univariate and multivariate log-binomial models estimated unadjusted and adjusted prevalence ratios (aPRs) and 95% confidence intervals (CI) for site-specific risk factors for LASV seropositivity. Grouped Least Absolute Shrinkage and Selection Operator (LASSO) was used for variable selection for multivariate analysis. Results A total of 628 participants with serum samples were included in the study. Most participants were female (434, 69%), married (459, 73%), and had a median age of 38 years (interquartile range 28–50). The overall seroprevalence was 27% (171/628), with a prevalence of 33% (126/376) in Abuja and 18% (45/252) in Lagos. Based on site-specific grouped LASSO selection, enrollment in the dry season (vs. wet; aPR, 95% CI: 1.73, 1.33–2.24), reported inconsistent washing of fruits and vegetables (aPR, 95% CI: 1.45, 1.10–1.92), and a positive malaria rapid test (aPR, 95% CI: 1.48, 1.09-2.00) were independently associated with LASV seropositivity in Abuja, whereas, only a self-reported history of rhinorrhea (PR, 95% CI: 2.21, 1.31–3.72) was independently associated with Lassa seropositivity in Lagos. Conclusions The LASV seroprevalence was comparable to that in other areas in Nigeria. Our findings corroborate those from other studies on the importance of limiting human exposure to rodents and focusing on behavioral factors such as poor hygiene practices to reduce exposure to LASV.
Læs mere Tjek på PubMedMalaria Journal, 8.10.2024
Tilføjet 8.10.2024
Abstract Background Battling malaria’s morbidity and mortality rates demands innovative methods related to malaria diagnosis. Thick blood smears (TBS) are the gold standard for diagnosing malaria, but their coloration quality is dependent on supplies and adherence to standard protocols. Machine learning has been proposed to automate diagnosis, but the impact of smear coloration on parasite detection has not yet been fully explored. Methods To develop Coloration Analysis in Malaria (CAM), an image database containing 600 images was created. The database was randomly divided into training (70%), validation (15%), and test (15%) sets. Nineteen feature vectors were studied based on variances, correlation coefficients, and histograms (specific variables from histograms, full histograms, and principal components from the histograms). The Machine Learning Matlab Toolbox was used to select the best candidate feature vectors and machine learning classifiers. The candidate classifiers were then tuned for validation and tested to ultimately select the best one. Results This work introduces CAM, a machine learning system designed for automatic TBS image quality analysis. The results demonstrated that the cubic SVM classifier outperformed others in classifying coloration quality in TBS, achieving a true negative rate of 95% and a true positive rate of 97%. Conclusions An image-based approach was developed to automatically evaluate the coloration quality of TBS. This finding highlights the potential of image-based analysis to assess TBS coloration quality. CAM is intended to function as a supportive tool for analyzing the coloration quality of thick blood smears.
Læs mere Tjek på PubMedMalaria Journal, 8.10.2024
Tilføjet 8.10.2024
Abstract Background Malaria is a global public health problem that disproportionately affects under-five children in poor resource countries. Nigeria accounted for the highest burden of malaria in Western Africa. Thus, seasonal malaria chemoprevention (SMC) programmes have been recommended and have been implemented across 9 states (Bauchi, Borno, FCT, Kebbi, Kogi, Nasarawa, Plateau, Oyo and Sokoto) in Nigeria. The study aims to measure the adherence to referral protocol and its associated factors among community drug distributors (CDs) and caregivers during SMC implementation in nine states. Methods The data of caregiver-child pairs that were identified with fever during the cycle one SMC implementation was extracted from the End-of-cycle (EoC) surveys carried out following cycles one SMC implementation in the study states. The surveys were completed within two weeks of the completion of SMC cycle one. Mixed-effects multivariable logistic regression models were fitted to explore the factors associated with adherence to referrals among caregivers-child pairs. Results The socio-demographic characteristics of caregiver considered in the model were not found to be significantly associated with children down with fever taking to hospital for treatment, however the caregiver whose child was referred by CDs had significantly higher odds of seeking healthcare compared to those that were not referred (OR: 1.892, 95% CI 1.081–3.310, p = 0.025). There are higher odds of children seeking treatment among those that were referred by CDs. Conclusion The study\'s findings shed light on the adherence to referral advice and the factors influencing caregiver behaviour during SMC implementation. Referral of sick child during SMC campaign appears to ensure health-seeking for malaria case management among caregivers-child peer in target communities.
Læs mere Tjek på PubMedJournal of Infectious Diseases, 8.10.2024
Tilføjet 8.10.2024
Abstract Background In Africa, the first Plasmodium falciparum artemisinin partial resistance mutation, was Kelch13 (K13) 561H - detected and validated at appreciable frequency in Rwanda in 2014. Surveillance to better define the extent of the emergence in Rwanda and neighboring countries is critical.Methods We used novel liquid blood drop preservation combined with pooled sequencing to provide cost-effective rapid assessment of resistance mutation frequencies at multiple collection sites across Rwanda and neighboring regions in Uganda, Tanzania, and the Democratic Republic of the Congo (DRC). Malaria-positive samples (n=5,465) from 39 health facilities collected between May 2022 and March 2023 were sequenced in 199 pools.Results In Rwanda, K13 561H and 675V were detected in 90% and 65% of sites with an average frequency of 19.0% (0-54.5%) and 5.0% (0-35.5%), respectively. In Tanzania, 561H had high frequency in multiple sites. 561H appeared at 1.6% in Uganda. 561H was absent from the DRC, although 675V was seen at low frequency. Concerningly candidate mutations were observed: 441L, 449A, and 469F co-occurred with validated mutations suggesting they are arising under the same pressures. Other markers for decreased susceptibility to artemether-lumefantrine are common: P. falciparum multidrug resistance protein 1 N86 at 98.0% (63.3-100%) and 184F at 47.0% (0-94.3%) and P. falciparum chloroquine resistance transporter 76T at 14.7% (0-58.6%). Additionally, sulfadoxine-pyrimethamine-associated mutations show high frequencies.Conclusion K13 mutations are rapidly expanding in the region further endangering control efforts with the potential of engendering partner drug resistance.
Læs mere Tjek på PubMedMalaria Journal, 6.10.2024
Tilføjet 6.10.2024
Abstract Background Namibia, a low malaria transmission country targeting elimination, has made substantial progress in reducing malaria burden through improved case management, widespread indoor residual spraying and distribution of insecticidal nets. The country\'s diverse landscape includes regions with varying population densities and geographical niches, with the north of the country prone to periodic outbreaks. As Namibia approaches elimination, malaria transmission has clustered into distinct foci, the identification of which is essential for deployment of targeted interventions to attain the southern Africa Elimination Eight Initiative targets by 2030. Geospatial modelling provides an effective mechanism to identify these foci, synthesizing aggregate routinely collected case counts with gridded environmental covariates to downscale case data into high-resolution risk maps. Methods This study introduces innovative infectious disease mapping techniques to generate high-resolution spatio-temporal risk maps for malaria in Namibia. A two-stage approach is employed to create maps using statistical Bayesian modelling to combine environmental covariates, population data, and clinical malaria case counts gathered from the routine surveillance system between 2018 and 2021. Results A fine-scale spatial endemicity surface was produced for annual average incidence, followed by a spatio-temporal modelling of seasonal fluctuations in weekly incidence and aggregated further to district level. A seasonal profile was inferred across most districts of the country, where cases rose from late December/early January to a peak around early April and then declined rapidly to a low level from July to December. There was a high degree of spatial heterogeneity in incidence, with much higher rates observed in the northern part and some local epidemic occurrence in specific districts sporadically. Conclusions While the study acknowledges certain limitations, such as population mobility and incomplete clinical case reporting, it underscores the importance of continuously refining geostatistical techniques to provide timely and accurate support for malaria elimination efforts. The high-resolution spatial risk maps presented in this study have been instrumental in guiding the Namibian Ministry of Health and Social Services in prioritizing and targeting malaria prevention efforts. This two-stage spatio-temporal approach offers a valuable tool for identifying hotspots and monitoring malaria risk patterns, ultimately contributing to the achievement of national and sub-national elimination goals.
Læs mere Tjek på PubMedMalaria Journal, 5.10.2024
Tilføjet 5.10.2024
Abstract Background Parenteral artesunate is the first-line therapy for severe malaria. Artesunate, in its current formulation, must be prepared immediately before administration by first dissolving in sodium bicarbonate solution and then diluting in saline. A novel solvent for rapid and stable single step reconstitution of artesunate was recently developed showing improved solubility and stability. This study aimed to compare the safety and pharmacokinetic properties of the currently available and newly developed parenteral formulation of artesunate in healthy Thai volunteers. Methods This was an open-label, randomized, 4 periods, 4-treatments, 24-sequence, single-dose, cross-over study in 72 male and female healthy Thai volunteers. Frequent pharmacokinetic samples were collected in all volunteers at each dose occasion. Observed concentration–time profiles were analysed with a non-compartmental approach followed by a bioequivalence evaluation. Results Both intramuscular and intravenous administrations of the new parenteral formulation of artesunate were safe and well-tolerated, with no additional safety signals compared to the currently used formulation. The pharmacokinetic properties of artesunate and its active metabolite, dihydroartemisinin, were well-characterized, and showed rapid conversion of artesunate into dihydroartemisinin. Intramuscular administration of the newly formulated artesunate resulted in almost complete bioavailability of dihydroartemisinin. The pharmacokinetic properties were similar between the old and new formulation. Conclusions The new and more easily prepared formulation of artesunate was safe and well-tolerated, with similar pharmacokinetic properties compared to the currently used formulation. Dihydroartemisinin, the active metabolite responsible for the majority of the anti-malarial effect, showed equivalent exposure after both intravenous and intramuscular administration of artesunate, suggesting that both routes of administration should generate comparable therapeutic effects. Trial registration: The study was registered to clinicaltrials.gov (#TCTR20170907002).
Læs mere Tjek på PubMedSoumitra GuinMarhiah C. MontoyaXiaoyu WangRobert ZarnowskiDavid R. AndesMarvin J. MeyersNoelle S. WilliamsDamian J. Krysan1Department of Chemistry, School of Science and Engineering, Saint Louis University, Saint Louis, Missouri, USA2Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA3Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA4Department of Medicine, Section of Infectious Disease, University of Wisconsin, Madison, Wisconsin, USA5Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, USA6Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USAAudrey Odom John
Antimicrobial Agents And Chemotherapy, 5.10.2024
Tilføjet 5.10.2024
Nimita Deora, Abhinav Sinha
Clinical Microbiology and Infection, 5.10.2024
Tilføjet 5.10.2024
In 2022, there were 249 million estimated malaria cases worldwide and WHO African and South-East Asia (SEAR) regions contributed >95% of these cases with India as major contributor from SEAR (1). P. falciparum is the dominant species causing malaria and sulfadoxine-pyrimethamine (SP) is used as a frontline drug for intermittent preventive treatment in pregnancy (standalone) and seasonal malaria chemoprevention in children in Africa and for uncomplicated P. falciparum malaria in India (excepting the north-eastern states) as artemisinin-based combination therapy.
Læs mere Tjek på PubMedJohn Okombo, David A. Fidock
Nat Rev Microbiol, 5.10.2024
Tilføjet 5.10.2024
Malaria Journal, 4.10.2024
Tilføjet 4.10.2024
Abstract Background Despite advances made in curbing the global malaria burden since the 2000s, progress has stalled, in part due to a plateauing of the financing available to implement needed interventions. In 2020, approximately 3.3 billion USD was invested globally for malaria interventions, falling short of the targeted 6.8 billion USD set by the GTS, increasing the financial gap between desirable and actual investment. Models for malaria control optimization are used to disentangle the most efficient interventions or packages of interventions for inherently constrained budgets. This systematic review aimed to identify and characterise models for malaria control optimization for resource allocation in limited resource settings and assess their strengths and limitations. Methods Following the Prospective Register of Systematic Reviews and Preferred reporting Items for Systematic Reviews and Meta-Analysis guidelines, a comprehensive search across PubMed and Embase databases was performed of peer-reviewed literature published from inception until June 2024. The following keywords were used: optimization model; malaria; control interventions; elimination interventions. Editorials, commentaries, opinion papers, conference abstracts, media reports, letters, bulletins, pre-prints, grey literature, non-English language studies, systematic reviews and meta-analyses were excluded from the search. Results The search yielded 2950 records, of which 15 met the inclusion criteria. The studies were carried out mainly in countries in Africa (53.3%), such as Ghana, Nigeria, Tanzania, Uganda, and countries in Asia (26.7%), such as Thailand and Myanmar. The most used interventions for analyses were insecticide-treated bed nets (93.3%), IRS (80.0%), Seasonal Malaria Chemoprevention (33.3%) and Case management (33.3%). The methods used for estimating health benefits were compartmental models (40.0%), individual-based models (40.0%), static models (13.0%) and linear regression model (7%). Data used in the analysis were validated country-specific data (60.0%) or non-country-specific data (40.0%) and were analysed at national only (40.0%), national and subnational levels (46.7%), or subnational only levels (13.3%). Conclusion This review identified available optimization models for malaria resource allocation. The findings highlighted the need for country-specific analysis for malaria control optimization, the use of country-specific epidemiological and cost data in performing modelling analyses, performing cost sensitivity analyses and defining the perspective for the analysis, with an emphasis on subnational tailoring for data collection and analysis for more accurate and good quality results. It is critical that the future modelling efforts account for fairness and target at risk malaria populations that are hard-to-reach to maximize impact. Trial registration: PROSPERO Registration number: CRD42023436966
Læs mere Tjek på PubMedBMC Infectious Diseases, 4.10.2024
Tilføjet 4.10.2024
Abstract Background Malaria disease is one of the most dangerous protozoan parasitic infections with a high mortality rate in developing countries. Malaria is a public health issue, especially in Hormozgan province, and is highly affected by foreign immigrants (Pakistani and Afghani); thus, the present study aimed to evaluate the effect of an intervention based on the health belief model (HBM) on the promotion of malaria prevention behaviors in Afghani immigrants over the age of 18. The participants resided in Persian city in Hormozgan province. Methods The present quasi-experimental study was conducted on 200 Afghans immigrants over 18 years of age who visited four comprehensive health service centers in Parsian city, south of Iran in June until December 2023. Sampling was by cluster method. In this way, the health centers were considered as clusters, and then 4 centers were randomly selected from among them (two centers of the control group and two centers of the intervention group) and participants were selected by a systematic random method by list of records in the National Integrated Health Record System (called SIB) (100participants control group, 100 participants intervention group). The data were collected using a researcher-made questionnaire based on the HBM before and after the educational intervention An educational program was designed and implemented to promote preventive behaviors against malaria in five sessions using different strategies and based on the HBM for the intervention group. The data were analyzed using independent-samples T-test, paired-samples T-test, Pearson’s correlation coefficient, analysis of covariance and linear regression. All statistical analyses and hypothesis testing were done in IBM SPSS version 25, at a significance level of 0.05. Results In the intervention group, there was a significant difference in the mean scores of knowledge (6.48, 95% CI: 5.9,7.05), perceived susceptibility (10.57, 95% CI: 10.03, 11.1), perceived severity (16.61, 95% CI: 15.83, 16.83), perceived self-efficacy (18.26, 95% CI: 17.55, 18.96), perceived benefits (15.43, 95% CI: 14.68, 16.17), perceived barriers (-22.49, 95% CI: -23.63, -21.30), cues to action (15.06, 95% CI: 14.36, 15.75), and preventive behaviors (20.05, 95% CI: 19.44, 20.65), before and after the educational intervention. P-value
Læs mere Tjek på PubMedMalaria Journal, 3.10.2024
Tilføjet 3.10.2024
Abstract Background Avian malaria is caused by diverse parasite species of the genus Plasmodium, and it affects various bird species. The occurrence of this disease in some wild bird species is sparsely documented due to the scarce availability of samples. Hence the pathogenicity in some hosts is not completely known. In addition, feral birds may act as reservoirs bridging the transmission cycle from wild migratory birds to domestic and zoo-kept bird species. Case presentation An owner of pigeons adopted a feral pigeon (Columba livia forma domestica) and housed it together with his other pet-pigeons. The bird died unexpectedly a few weeks after a surgical procedure and necropsy revealed a severely anaemic carcass, with pale organs and hydropericardium. Histopathologic analysis revealed inflammatory infiltrates in the lung and liver, and monocytes and Kupffer cells contained haemozoin pigment indicative of phagocytosis of Plasmodium-infected erythrocytes. A high erythrocytic infection rate of 18% was evident in tissues and blood vessels in various organs. Furthermore, the thyroid had masses classified as thyroid carcinomas. Immunohistochemistry with anti- Plasmodium falciparum HSP70 antibody revealed positive signals in erythrocytes and intravascular leucocytes. Further microscopy analysis using a Hemacolor-stained impression smear revealed a high parasitaemia with an asynchronous infection showing all erythrocytic stages. Molecular diagnosis by PCR identified Plasmodium relictum, lineage GRW11 as the aetiological agent. The bird presented died most likely due to an acute infection as evidenced by the high blood parasitaemia, leading to major erythrocyte destruction. Further analyses of feral pigeons (n = 22) did not reveal any additional cases of Plasmodium infections. Conclusion This study reports the first mortality associated with P. relictum lineage GRW11. The study supports previous studies, suggesting that Plasmodium infections are not frequent in pigeons. Host conditions like immunosuppression due to the tumour may have influenced the infection outcome in this fatal case. Use of anti-P. falciparum HSP70 antibody for detection of P. relictum antigens for immune assays in blood and tissue samples will be a useful tool for future studies.
Læs mere Tjek på PubMedAmerican Journal of Tropical Medicine and Hygiene, 3.10.2024
Tilføjet 3.10.2024
Journal Name: The American Journal of Tropical Medicine and Hygiene Volume: 111 Issue: 4 Pages: 765-769
Læs mere Tjek på PubMedAmerican Journal of Tropical Medicine and Hygiene, 3.10.2024
Tilføjet 3.10.2024
Journal Name: The American Journal of Tropical Medicine and Hygiene Volume: 111 Issue: 4 Pages: 770-779
Læs mere Tjek på PubMedAmerican Journal of Tropical Medicine and Hygiene, 3.10.2024
Tilføjet 3.10.2024
Journal Name: The American Journal of Tropical Medicine and Hygiene Volume: 111 Issue: 4 Pages: 780-784
Læs mere Tjek på PubMedMalaria Journal, 2.10.2024
Tilføjet 2.10.2024
Abstract Background Dissemination and outcome reporting biases are a significant problem in clinical research, with far-reaching implications for both scientific understanding and clinical decision-making. This study investigates the prevalence of dissemination- and outcome reporting biases in registered interventional malaria research. Methods All malaria interventional trials registered on ClinicalTrials.gov from 2010 to 2020 were identified. Subsequently, publications that matched the registration were searched. The primary outcome measures were the percentage of registered studies that resulted in subsequent publication of study results, the concordance between registered outcomes, and reported outcomes. Secondary outcomes were compliance with WHO standards for timely publication (issued in 2017) of summary study results in the respective trial registry (within 12 months of study completion) or peer-reviewed publication (within 24 months of study completion) was evaluated. Results A total of 579 trials were identified on ClinicalTrials.gov, of which 544 met the inclusion criteria. Notably, almost 36.6% of these trials (199/544) were registered retrospectively, with 129 (23.7%) registered after the first patient enrolment and 70 (12.9%) following study completion. Publications were identified for 351 out of 544 registered trials (64.5%), involving 1,526,081 study participants. Conversely, publications were not found for 193 of the 544 registrations (35.5%), which aimed to enrol 417,922 study participants. Among these 544 registrations, 444 (81.6%) did not meet the WHO standard to post summary results within 12 months of primary study completion (the last visit of the last subject for collection of data on the primary outcome), while 386 out of 544 registrations (71.0%) failed to publish their results in a peer-reviewed journal within 24 months of primary study completion. Discrepancies were noted in the reported primary outcomes compared to the registered primary outcomes in 47.6% (222/466) of the published trials, and an even higher discordance rate of 73.2% (341/466 publications) for secondary outcomes. Conclusions Non-dissemination remains a significant issue in interventional malaria research, with most trials failing to meet WHO standards for timely dissemination of summary results and peer-reviewed journal publications. Additionally, outcome reporting bias is highly prevalent across malaria publications. To address these challenges, it is crucial to implement strategies that enhance the timely reporting of research findings and reduce both non-dissemination and outcome reporting bias.
Læs mere Tjek på PubMedMalaria Journal, 2.10.2024
Tilføjet 2.10.2024
Abstract Background Malaria is a major disease burden in Ethiopia. Migration can influence malaria transmission dynamics, with individuals relocating from malaria-free highland regions to malarious lowlands potentially facing elevated risks of contracting malaria. Migrants may find it difficult to protect themselves against malaria and have limited access to diagnosis or treatment. Settlers in gold mining sites are one type of migrant and are often neglected in malaria research yet may have particularly high malaria risk. This study was a malaria prevalence survey among settlers in a new gold mining settlement in the highly malarious Gambella Region, Ethiopia. Methods n = 590 people were surveyed for demographic information and their knowledge and practices of malaria. Participants were tested for malaria using rapid diagnostic tests and microscopy. Using logistic regressions, the influence of demographic characteristics on malaria infections and bed net access were analysed. A sub-sample of participants was interviewed to comprehend settlement living conditions and healthcare accessibility. Results The overall prevalence of Plasmodium falciparum was 37.5% (CI 32.4–42.3%). Young children were most likely to have malaria, with individuals aged 15–24 having 67% lower odds (aOR: 0.33; CI 0.13–0.86) of infection compared to those aged 1–4 years old. Meanwhile, those age 25-plus had 75% decreased odds of malaria infection (aOR 0.25; CI 0.10–0.65). Individuals with bed nets had ~ 50% decreased odds of testing positive for falciparum malaria than those reporting having no bed net (aOR: 0.47; CI 0.22–0.97). Individuals who relocated from low elevation with high malaria test positivity rate areas were more prone to testing positive for malaria, as were those residing in densely populated households with multiple malaria cases. Conversely, individuals from higher elevations with low malaria test positivity rates, and those living in households with 5–10 occupants and
Læs mere Tjek på PubMedMichal Kucharski, Sourav Nayak, Mathieu Gendrot, Arjen M. Dondorp, Zbynek Bozdech
Trends in Parasitology, 2.10.2024
Tilføjet 2.10.2024
The genetics of Plasmodium as an intracellular, mostly haploid, sexually reproducing, eukaryotic organism with a complex life cycle, presents unprecedented challenges in studying drug resistance. This article summarizes current knowledge on the genetic basis of artemisinin resistance (AR) – a main component of current drug therapies for falciparum malaria. Although centered on nonsynonymous single-nucleotide polymorphisms (nsSNPs), we describe multifaceted resistance mechanisms as part of a complex, cumulative genetic trait that involves regulation of expression by a wide array of polymorphisms in noncoding regions. These genetic variations alter transcriptome profiles linked to Plasmodium\'s development and population dynamics, ultimately influencing the emergence and spread of the resistance.
Læs mere Tjek på PubMedBMC Infectious Diseases, 1.10.2024
Tilføjet 1.10.2024
Abstract Background False negative rapid diagnostic tests (RDTs) accruing to the non-detection of Plasmodium falciparum histidine-rich protein 2/3 (Pfhrp2/3) is threatening the diagnosis and management of malaria. Although regular monitoring is necessary to gauge the level of efficacy of the tool, studies in Cameroon remain limited. This study assessed Plasmodium spp. prevalence and Pfhrp2/3 gene deletions across ecological and transmission zones in Cameroon. Methods This is a cross-sectional, multi-site, community- and hospital- based study, in 21 health facilities and 14 communities covering all five ecological settings in low seasonal (LS) and intense perennial (IPT) malaria transmission zones between 2019 and 2021. Participants were screened for malaria parasite using Pfhrp2 RDT and light microscopic examination of thick peripheral blood smears. DNA was extracted from dried blood spot using chelex®-100 and P. falciparum confirmed using varATS real-time quantitative Polymerase Chain Reaction (qPCR), P. malariae and P. ovale by real-time qPCR of Plasmepsin gene, and P. vivax using a commercial kit. Isolates with amplified Pfcsp and Pfama-1 genes were assayed for Pfhrp 2/3 gene deletions by conventional PCR. Results A total of 3,373 participants enrolled, 1,786 Plasmodium spp. infected, with 77.4% P. falciparum. Discordant RDT and qPCR results (False negatives) were reported in 191 (15.7%) P. falciparum mono-infected samples from LS (29%, 42) and IPT (13.9%, 149). The Pfhrp2+/Pfhrp3 + genotype was most frequent, similar between LS (5.5%, 8/145) and IPT (6.0%, 65/1,076). Single Pfhrp2 and Pfhrp3 gene deletions occurred in LS (0.7%, 1/145 each) and IPT (3.6%, 39/1,076 vs. 2.9%, 31/1,076), respectively. Whilst a single sample harboured Pfhrp2-/Pfhrp3- genotype in LS, 2.4% (26/1,076) were double deleted at IPT. Pfhrp2+/Pfhrp3- (0.3%, 3/1,076) and Pfhrp2-/Pfhrp3+ (1.2%, 13/1,076) genotypes were only observed in IPT. Pfhrp2, Pfhrp3 deletions and Pfhrp2-/Pfhrp3- genotype accounted for 78.8% (26), 69.7% (23) and 63.6% (21) RDT false negatives, respectively. Conclusion Plasmodium falciparum remains the most dominant and widely distributed Plasmodium species across transmission and ecological zones in Cameroon. Although the low prevalence of Pfhrp2/3 gene deletions supports the continued use of HRP2-based RDTs for routine malaria diagnosis, the high proportion of false-negatives due to gene deleted parasites necessitates continued surveillance to inform control and elimination efforts.
Læs mere Tjek på PubMedMalaria Journal, 29.09.2024
Tilføjet 29.09.2024
Abstract Background Malaria continues to cause unacceptably high levels of disease and death despite increased global efforts and is still significant public health problem. African countries are disproportionately affected by malaria. The objective of this study was to describe a rare case of haemorrhagic stroke as a possible complication of malaria in a 26-year-old male patient. Case presentation A 26-year-old male from southwest Ethiopia presented with complaint of loss of consciousness (LOC) of 12 h duration. He had fever, headache, vomiting, chills, rigors and shivering three days prior to the loss of consciousness. On physical examination, pulse rate 116 beats/min, blood pressure of 120/90 mmHg, respiratory rate was 24 breaths/min, a temperature of 38.9◦C and oxygen saturation of 94%. Nervous system examination; stuporous with Glasgow Coma Scale (GCS) 10/15(M5, E3, V2). Blood film and RDT confirmed a Plasmodium falciparum infection and a non-contrast CT scan found a right cerebral parenchymal haemorrhage. Discussion and conclusion The presented case described a very rare case of a 26-year-old male patient who was diagnosed with left side hemiparesis secondary to a haemorrhagic stroke, associated with P. falciparum malaria. This report highlights the fact that malaria with stroke should be considered a differential diagnosis in a patient presenting with body weakness in a malaria endemic area and in individuals who had travel history to malaria endemic areas.
Læs mere Tjek på PubMedBMC Infectious Diseases, 29.09.2024
Tilføjet 29.09.2024
Abstract Background Malaria is an intravascular parasitic-related blood disease that causes bleeding, coagulopathy, and thrombocytopenia. However, limited data shows the effect of Plasmodium species infection on basic coagulation parameters and platelet count. Thus, this study aimed to assess basic coagulation parameters and platelet count among malaria patients. Method A cross-sectional study was conducted among 240 study participants (120 cases and 120 controls) from June 1, 2021, to February 30, 2022. A convenient sampling technique was employed to select study participants. The blood sample was collected by a trained laboratory technologist for platelet counts, prothrombin time (PT), partial thromboplastin time (PTT), international normalization ratio (INR), blood film, and serological testing. The collected data were analyzed in SPSS version 23. Data were analyzed by the Mann-Whitney U test, Kruskal Wallis H, and Spearman’s rank-order correlation tests. Descriptive findings were presented through median, tables, and chart. In all cases, a P-value
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