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47 ud af 47 tidsskrifter valgt, søgeord (malaria) valgt, emner højest 180 dage gamle, sorteret efter nyeste først.
353 emner vises.
Adetunji, A., Adediran, M., Etim, E.-O. E., Bazzano, A. N.
BMJ Open, 9.12.2023
Tilføjet 9.12.2023
ObjectiveThis paper examines the acceptance of the Advocacy Core Group (ACG) programme, a social and behaviour change intervention addressing maternal, newborn, child health and nutrition (MNCH+N) in Bauchi and Sokoto states, with an additional focus on the perceived endorsement of health behaviours by social networks as a potential factor influencing acceptance. DesignThis study used the qualitative social network analysis approach and used in-depth interviews to collect data from 36 participants across Bauchi and Sokoto states. SettingThis study was conducted in selected communities across Bauchi and Sokoto states. ParticipantsA purposive sample of 36 participants comprised of men and women aged 15–49 years who have been exposed to the ACG programme. ResultsProgramme beneficiaries actively engaged in various ACG-related activities, including health messaging delivered through religious houses, social gatherings, home visits, community meetings and the media. As a result, they reported a perceived change in behaviour regarding exclusive breast feeding, antenatal care visits, family planning and malaria prevention. Our findings indicated consistent discussions on health behaviours between programme beneficiaries and their network partners (NPs), with a perceived endorsement of these behaviours by the NPs. However, a potential negative factor emerged, whereby NPs exhibited perceived disapproval of key behaviours, which poses a threat to behaviour adoption and, consequently, the success of the ACG model. ConclusionsWhile findings suggest the successful implementation and acceptance of the model, it is important to address possible barriers and to further explore the socially determined acceptance of MNCH+N behaviours by NPs. Interventions such as the ACG model should mobilise the networks of programme participants, particularly those with decision-making power, to improve the uptake of health behaviours.
Læs mere Tjek på PubMedMalaria Journal, 9.12.2023
Tilføjet 9.12.2023
Abstract Background Anopheles stephensi is an emerging exotic invasive urban malaria vector in East Africa. The World Health Organization recently announced an initiative to take concerted actions to limit this vector’s expansion by strengthening surveillance and control in invaded and potentially receptive territories in Africa. This study sought to determine the invasion of An. stephensi in southern Ethiopia. Methods A targeted entomological survey, both larvae and adult, was conducted in Hawassa City, southern Ethiopia between November 2022 and February 2023. Anopheles larvae were reared to adults for species identification. CDC light traps and BG Pro traps were used indoors and outdoors overnight at selected houses to collect adult mosquitoes in the study area. Prokopack aspirator was employed to sample indoor resting mosquitoes in the morning. Adults of An. stephensi was identified using morphological keys and then confirmed by PCR. Results Larvae of An. stephensi were found in 28 (16.6%) of the 169 potential mosquito breeding sites surveyed. Out of 548 adult female Anopheles mosquitoes reared from larvae, 234 (42.7%) were identified as An. stephensi morphologically. A total of 449 female anophelines were caught, of which 53 (12.0%) were An. stephensi. Other anopheline species collected in the study area included Anopheles gambiae sensu lato (s.l.), Anopheles pharoensis, Anopheles coustani, and Anopheles demeilloni. Conclusion This study confirmed the presence of An. stephensi in southern Ethiopia. The presence of both larval and adult stages of this mosquito attests that this species established sympatric colonization with native vector species such as An. gambiae (s.l.) in southern Ethiopia. The findings warrant further investigation on the ecology, behaviour, population genetics, and role of An. stephensi in malaria transmission in Ethiopia.
Læs mere Tjek på PubMedMalaria Journal, 9.12.2023
Tilføjet 9.12.2023
Abstract Background Anopheles stephensi is an emerging exotic invasive urban malaria vector in East Africa. The World Health Organization recently announced an initiative to take concerted actions to limit this vector’s expansion by strengthening surveillance and control in invaded and potentially receptive territories in Africa. This study sought to determine the invasion of An. stephensi in southern Ethiopia. Methods A targeted entomological survey, both larvae and adult, was conducted in Hawassa City, southern Ethiopia between November 2022 and February 2023. Anopheles larvae were reared to adults for species identification. CDC light traps and BG Pro traps were used indoors and outdoors overnight at selected houses to collect adult mosquitoes in the study area. Prokopack aspirator was employed to sample indoor resting mosquitoes in the morning. Adults of An. stephensi was identified using morphological keys and then confirmed by PCR. Results Larvae of An. stephensi were found in 28 (16.6%) of the 169 potential mosquito breeding sites surveyed. Out of 548 adult female Anopheles mosquitoes reared from larvae, 234 (42.7%) were identified as An. stephensi morphologically. A total of 449 female anophelines were caught, of which 53 (12.0%) were An. stephensi. Other anopheline species collected in the study area included Anopheles gambiae sensu lato (s.l.), Anopheles pharoensis, Anopheles coustani, and Anopheles demeilloni. Conclusion This study confirmed the presence of An. stephensi in southern Ethiopia. The presence of both larval and adult stages of this mosquito attests that this species established sympatric colonization with native vector species such as An. gambiae (s.l.) in southern Ethiopia. The findings warrant further investigation on the ecology, behaviour, population genetics, and role of An. stephensi in malaria transmission in Ethiopia.
Læs mere Tjek på PubMedSamuel C. Wassmer, Tania F. de Koning-Ward, Georges E.R. Grau, Saparna Pai
Trends in Parasitology, 8.12.2023
Tilføjet 8.12.2023
Cerebral malaria (CM) is a severe neurological complication caused by Plasmodium falciparum parasites; it is characterized by the sequestration of infected red blood cells within the cerebral microvasculature. New findings, combined with a better understanding of the central nervous system (CNS) barriers, have provided greater insight into the players and events involved in CM, including site-specific T cell responses in the human brain. Here, we review the updated roles of innate and adaptive immune responses in CM, with a focus on the role of the perivascular macrophage–endothelium unit in antigen presentation, in the vascular and perivascular compartments. We suggest that these events may be pivotal in the development of CM.
Læs mere Tjek på PubMedTobias Kasper, Gavin Yamey, Sinead Dwyer, Kaci Kennedy McDade, Jon Lidén, Cora Lüdemann, Mohamed Mustafa Diab, Osondu Ogbuoji, Prashant Poodla, Christina Schrade, Andrea Thoumi, Armand Zimmerman, Yibeltal Assefa, Luke N Allen, Paulin Basinga, Patricia J Garcia, Debra Jackson, Henry Mwanyika, Rachel Nugent, Anthony Ofosu, Salman Rawaf, K Srinath Reddy, Dykki Settle, Beth Tritter, Christoph Benn
Lancet, 8.12.2023
Tilføjet 8.12.2023
Global campaigns to control HIV, tuberculosis, malaria, and vaccine-preventable illnesses showed that large-scale impact can be achieved by using additional international financing to support selected, evidence-based, high-impact investment areas and to catalyse domestic resource mobilisation. Building on this paradigm, we make the case for targeting additional international funding for selected high-impact investments in primary health care. We have identified and costed a set of concrete, evidence-based investments that donors could support, which would be expected to have major impacts at an affordable cost.
Læs mere Tjek på PubMedMalaria Journal, 8.12.2023
Tilføjet 8.12.2023
Abstract Background The use of primaquine for mass drug administration (MDA) is being considered as a key strategy for malaria elimination. In addition to being the only drug active against the dormant and relapsing forms of Plasmodium vivax, primaquine is the sole potent drug against mature/infectious Plasmodium falciparum gametocytes. It may prevent onward transmission and help contain the spread of artemisinin resistance. However, higher dose of primaquine is associated with the risk of acute haemolytic anaemia in individuals with a deficiency in glucose-6-phosphate dehydrogenase. In many P. falciparum endemic areas there is paucity of information about the distribution of individuals at risk of primaquine-induced haemolysis at higher dose 45 mg of primaquine. Methods A retrospective cross-sectional study was carried out using archived samples to establish the prevalence of G6PD deficiency in a malaria hotspot area in Misungwi district, located in Mwanza region, Tanzania. Blood samples collected from individuals recruited between August and November 2010 were genotyped for G6PD deficiency and submicroscopic parasites carriage using polymerase chain reaction. Results A total of 263 individuals aged between 0 and 87 were recruited. The overall prevalence of the X-linked G6PD A− mutation was 83.7% (220/263) wild type, 8% (21/263) heterozygous and 8.4% (22/263) homozygous or hemizygous. Although, assessment of the enzymatic activity to assign the phenotypes according to severity and clinical manifestation as per WHO was not carried out, the overall genotype and allele frequency for the G6PD deficiency was 16.4% and 13. 2%, respectively. There was no statistically significant difference in among the different G6PD genotypes (p > 0.05). Out of 248 samples analysed for submicroscopic parasites carriage, 58.1% (144/248) were P. falciparum positive by PCR. G6PD heterozygous deficiency were associated with carriage of submicroscopic P. falciparum (p = 0.029). Conclusions This study showed that 16.4% of the population in this part of North-western Tanzania carry the G6PD A− mutation, within the range of 15–32% seen in other parts of Africa. G6PD gene mutation is widespread and heterogeneous across the study area where primaquine would be valuable for malaria control and elimination. The maps and population estimates presented here reflect potential risk of higher dose of primaquine being associated with the risk of acute haemolytic anaemia (AHA) in individuals with a deficiency in glucose-6-phosphate dehydrogenase and call further research on mapping of G6PD deficiency in Tanzania. Therefore, screening and education programmes for G6PD deficiency is warranted in a programme of malaria elimination using a higher primaquine dose.
Læs mere Tjek på PubMedAmerican Journal of Tropical Medicine and Hygiene, 7.12.2023
Tilføjet 7.12.2023
Journal Name: The American Journal of Tropical Medicine and Hygiene Volume: 109 Issue: 6 Pages: 1356-1362
Læs mere Tjek på PubMedAmerican Journal of Tropical Medicine and Hygiene, 7.12.2023
Tilføjet 7.12.2023
Journal Name: The American Journal of Tropical Medicine and Hygiene Volume: 109 Issue: 6 Pages: 1363-1367
Læs mere Tjek på PubMedMalaria Journal, 5.12.2023
Tilføjet 5.12.2023
Abstract Background Malaria is one of the most prominent illnesses affecting children, ranking as one of the key development concerns for many low- and middle-income countries (LMICs). There is not much information available on the use of anti-malarial drugs in LMICs in children under five. The study aimed to investigate disparities in anti-malarial drug consumption for malaria among children under the age of five in LMICs. Methods This study used recent available cross-sectional data from the Malaria Indicator Survey (MIS) datasets across five LMICs (Guinea, Kenya, Mali, Nigeria, and Sierra Leone), which covered a portion of sub-Saharan Africa. The study was carried out between January 2, 2023, and April 15, 2023, and included children under the age of five who had taken an anti-malarial drug for malaria 2 weeks before the survey date. The outcome variable was anti-malarial drug consumption, which was classified into two groups: those who had taken anti-malarial drugs and those who had not. Results In the study of LMICs, 32,397 children under five were observed, and among them, 44.1% had received anti-malarial drugs. Of the five LMICs, Kenya had the lowest (9.2%) and Mali had the highest (70.5%) percentages of anti-malarial drug consumption. Children under five with malaria are more likely to receive anti-malarial drugs if they are over 1 year old, live in rural areas, have mothers with higher education levels, and come from wealthier families. Conclusion The study emphasizes the importance of developing universal coverage strategies for anti-malarial drug consumption at both the national and local levels. The study also recommends that improving availability and access to anti-malarial drugs may be necessary, as the consumption of these drugs for treating malaria in children under the age of five is shockingly low in some LMICs.
Læs mere Tjek på PubMedMalaria Journal, 5.12.2023
Tilføjet 5.12.2023
Abstract Background Children in sub-Saharan Africa (SSA) remain the most vulnerable to malaria and malaria mortality. This study estimated the disease burden and distribution of Plasmodium falciparum malaria among children with age categories (0 to
Læs mere Tjek på PubMedMalaria Journal, 5.12.2023
Tilføjet 5.12.2023
Abstract Background Plasmodium vivax has been more resistant to various control measures than Plasmodium falciparum malaria because of its greater transmissibility and ability to produce latent parasite forms. Therefore, developing P. vivax vaccines and therapeutic monoclonal antibodies (humAbs) remains a high priority. The Duffy antigen receptor for chemokines (DARC) expressed on erythrocytes is central to P. vivax invasion of reticulocytes. P. vivax expresses a Duffy binding protein (PvDBP) on merozoites, a DARC ligand, and the DARC: PvDBP interaction is critical for P. vivax blood stage malaria. Therefore, PvDBP is a leading vaccine candidate for P. vivax and a target for therapeutic human monoclonal antibodies (humAbs). Methods Here, the functional activity of humAbs derived from naturally exposed and vaccinated individuals are compared for the first time using easily cultured Plasmodium knowlesi (P. knowlesi) that had been genetically modified to replace its endogenous PkDBP orthologue with PvDBP to create a transgenic parasite, PkPvDBPOR. This transgenic parasite requires DARC to invade human erythrocytes but is not reticulocyte restricted. This model was used to evaluate the invasion inhibition potential of 12 humAbs (9 naturally acquired; 3 vaccine-induced) targeting PvDBP individually and in combinations using growth inhibition assays (GIAs). Results The PvDBP-specific humAbs demonstrated 70–100% inhibition of PkPvDBPOR invasion with the IC50 values ranging from 51 to 338 µg/mL for the 9 naturally acquired (NA) humAbs and 33 to 99 µg/ml for the 3 vaccine-induced (VI) humAbs. To evaluate antagonistic, additive, or synergistic effects, six pairwise combinations were performed using select humAbs. Of these combinations tested, one NA/NA (099100/094083) combination demonstrated relatively strong additive inhibition between 10 and 100 µg/mL; all combinations of NA and VI humAbs showed additive inhibition at concentrations below 25 µg/mL and antagonism at higher concentrations. None of the humAb combinations showed synergy. Invasion inhibition efficacy by some mAbs shown with PkPvDBPOR was closely replicated using P. vivax clinical isolates. Conclusion The PkPvDBPOR transgenic model is a robust surrogate of P. vivax to assess invasion and growth inhibition of human monoclonal Abs recognizing PvDBP individually and in combination. There was no synergistic interaction for growth inhibition with the humAbs tested here that target different epitopes or subdomains of PvDBP, suggesting little benefit in clinical trials using combinations of these humAbs.
Læs mere Tjek på PubMedJournal of Infectious Diseases, 4.12.2023
Tilføjet 4.12.2023
AbstractBackgroundAntimalarial drug resistance surveillance and containment are crucial for countries aiming to eliminate malaria. Monitoring resistance evolution through studies before and after treatment policy changes is crucial.MethodA total of 939 P. falciparum-positive blood samples were collected between 2014 and 2015 across ten sites in India, categorized into four geographic clusters. PCR-amplified products were sequenced to identify point mutations at drug-resistance-conferring genes (Pfdhfr, Pfdhps, Pfmdr1, Pfk13).ResultTriple Pfdhfr mutants were found only in northeast India bordering Myanmar, while the wildtype was dominant in central India. Pfdhps wildtypes were prevalent in all areas, and no double mutants were found. Except in Northwest India, Pfmdr1 wildtype was dominant in all clusters. Nonsynonymous double mutations were only found in northwest India. Only synonymous mutations occurred in Pfk13. These were found in Central India at low frequency. The pattern of linkage disequilibrium and principal component analysis reflects low pressure for drug resistance and heterogeneity between the geographic clusters.ConclusionResistance levels were highest in Northeast India, close to the Myanmar border, where resistance is common. Primaquine has been widely used as a gametocidal and schizonticidal drug, has likely contributed to maintaining low drug resistance levels and preventing strong selection for resistance.
Læs mere Tjek på PubMedTadesse Duguma, Dessalew Wudineh, Aberash Assefa, Nebeyi Fisseha, Dassalegn Muleta
PLoS One Infectious Diseases, 2.12.2023
Tilføjet 2.12.2023
by Tadesse Duguma, Dessalew Wudineh, Aberash Assefa, Nebeyi Fisseha, Dassalegn Muleta Background Malaria is a major cause of morbidity and mortality in children under the age of five worldwide. Although various malaria elimination measures have been implemented over the past decades, malaria remains a serious threat to public health, especially in tropical and subtropical areas. Ethiopia has set targets for eliminating malaria by 2030. No research has been conducted in the study area concerning malaria among children, who are the most malaria-prone segment of a community. The purpose of this study was to assess malaria prevalence and the factors associated with it among children under five years of age who attended the Sheko Health Center, Southwest Ethiopia, from June 1 to October 30, 2022. Materials and methods An institutional-based cross-sectional study was employed from June 1 to October 30, 2022, at the Sheko Health Center. Capillary blood samples were collected from 286 randomly selected symptomatic children. Data on socio-demographics and associated factors were collected using a pre-tested structured questionnaire, and data on parents’ and guardians’ knowledge about malaria was recorded on Excel 2016 Spreadsheets after interviewing them, and their responses were presented by a frequency table. Data were entered into Epi Data Manager (v4.0.2.101) and analyzed using the Statistical Package for Social Sciences (SPSS) version 25. Associated factors of malaria were analyzed using bivariate and multivariable logistic regression, and statistical significance was set at P < 0.05. Result Overall, 23.4% (95% CI = 18.6–28.8%) malaria infection was recorded among the children whose blood samples were examined, with Plasmodium falciparum, Plasmodium vivax, and mixed infections (both species) representing 52.2%, 34.3%, and 13.4% of the cases, respectively. The majority of the parents or guardians believed that malaria is transmissible but could be prevented, and 80% of them considered mosquito bites to be the main mode of malaria transmission. Insecticide-treated net (ITN) was mentioned as a malaria prevention strategy by more than half of the respondents, while indoor residual spraying (IRS) was considered only by 19.6%. Based on multivariable logistic regression analysis, a significant association was found in children between the ages of 12 and 36 months (adjusted odds ratio = 5.050; 95% CI: 1.964–12.982), children who lived in rural areas (adjusted odds ratio = 2.901; 95% CI: 1.439–5.845), and children who did not use ITN the past two weeks before sample collection (adjusted odds ratio = 3.341; 95% CI: 1.646–6.781). Conclusion This study revealed a high malaria prevalence among children aged under five years. Attention must be paid to improving the coverage of the ITN and its use in the study area, which could help reduce the risk of mosquito bites. Health education for the guardians of the children could also help to raise awareness about the prevention and control strategies for malaria transmission and further reduce the impact of the disease.
Læs mere Tjek på PubMedMalaria Journal, 2.12.2023
Tilføjet 2.12.2023
Abstract Background Pregnant women have an increased risk of Plasmodium infections and disease. Malaria in pregnancy is a major public health problem in endemic areas. Assessment of the burden and risk factors of malaria in pregnancy across different malaria transmission settings is required to guide control strategies and for malaria elimination. Thus, the current study is generating such evidence from parturient women in northwest Ethiopia. Methods A cross-sectional study was conducted among 526 pregnant women admitted to the delivery rooms of selected health facilities in Jawi district, northwest Ethiopia, between November 2021 and July 2022. Data on the socio-demographic, clinical, obstetric, and malaria prevention practices of pregnant women were collected using interviewer-administered questionnaires and from women’s treatment cards. Malaria was diagnosed by light microscopy, rapid diagnostic test, and multiplex real-time polymerase chain reaction. Risk factors for malaria were evaluated using bivariable and multivariable logistic regression models. A P-value of
Læs mere Tjek på PubMedMalaria Journal, 2.12.2023
Tilføjet 2.12.2023
Abstract Background Anopheles pharoensis has a major role in transmitting several human diseases, especially malaria, in Egypt?. Controlling Anopheles is considered as an effective strategy to eliminate the spread of malaria worldwide. Galaxaura rugosa is a species of red algae found in tropical to subtropical marine environments. The presence of G. rugosa is indicative of the ecosystem\'s overall health. The current work aims to investigate UPLC/ESI/MS profile of G. rugosa methanol and petroleum ether extracts and its activity against An. pharoensis and non-target organisms, Danio rerio and Daphnia magna. Methods Galaxaura rugosa specimens have been identified using DNA barcoding for the COI gene and verified as G. rugosa. The UPLC/ESI/MS profiling of G. rugosa collected from Egypt was described. The larvicidal and repellent activities of G. rugosa methanol and petroleum ether extracts against An. pharoensis were evaluated, as well as the toxicity of tested extracts on non-target organisms, Dan. rerio and Dap. magna. Results The UPLC/ESI/MS analysis of methanol and petroleum ether extracts led to the tentative identification of 57 compounds belonging to different phytochemical classes, including flavonoids, tannins, phenolic acids, phenyl propanoids. Larval mortality was recorded at 93.33% and 90.67% at 80 and 35 ppm of methanol and petroleum ether extracts, respectively, while pupal mortality recorded 44.44 and 22.48% at 35 and 30 ppm, respectively. Larval duration was recorded at 5.31 and 5.64 days by methanol and petroleum ether extracts at 80 and 35 ppm, respectively. A decrease in acetylcholinesterase (AChE) level and a promotion in Glutathione-S-transferase (GST) level of An. pharoensis 3rd instar larvae were recorded by tested extracts. The petroleum ether extract was more effective against An. pharoensis starved females than methanol extract. Also, tested extracts recorded LC50 of 1988.8, 1365.1, and 11.65, 14.36 µg/mL against Dan. rerio, and Dap. magna, respectively. Conclusions Using red algae derivatives in An. pharoensis control could reduce costs and environmental impact and be harmless to humans and other non-target organisms.
Læs mere Tjek på PubMedGeorges Snounou, Paul M. Sharp, Richard Culleton
Trends in Parasitology, 1.12.2023
Tilføjet 1.12.2023
Plasmodium ovale was the last of the exclusively human malaria parasites to be described, in 1922, and has remained the least well studied. Beginning in 1995, two divergent forms of the parasite, later termed ‘classic’ and ‘variant’, were described. By 2010, it was realised that these forms are two closely related, but genetically distinct and non-recombining species; they were given the names Plasmodium ovale curtisi and Plasmodium ovale wallikeri. Since then, substantial additional data have confirmed that the two parasites are indeed separate species, but the trinomial nomenclature has often led to confusion about their status, with many authors describing them as subspecies. We hereby formally name them Plasmodium ovalecurtisi and Plasmodium ovalewallikeri.
Læs mere Tjek på PubMedClinical Infectious Diseases, 1.12.2023
Tilføjet 1.12.2023
AbstractBackgroundRecent cases of clinical failure in UK malaria patients treated with artemether-lumefantrine have implications for malaria chemotherapy worldwide.MethodsParasites were isolated from an index case of confirmed Plasmodium falciparum treatment failure after standard treatment, and from comparable travel-acquired UK malaria cases. Drug susceptibility in vitro and genotypes at six resistance-associated loci were determined for all parasite isolates and compared with clinical outcomes for each parasite donor.ResultsA traveller, who returned to the UK from Uganda in 2022 with Plasmodium falciparum malaria, twice failed treatment with full courses of artemether-lumefantrine. Parasites from the patient exhibited significantly reduced susceptibility to artemisinin (ring-stage survival 17.3%; 95% C.I. 13.6 - 21.1 %; P
Læs mere Tjek på PubMedMalaria Journal, 1.12.2023
Tilføjet 1.12.2023
Abstract Background In 2020, the Zambia National Malaria Elimination Centre targeted the distribution of long-lasting insecticidal nets (LLINs) and indoor-residual spraying (IRS) campaigns based on sub-district micro-planning, where specified geographical areas at the health facility catchment level were assigned to receive either LLINs or IRS. Using data from the 2021 Malaria Indicator Survey (MIS), the objectives of this analysis were to (1) assess how well the micro-planning was followed in distributing LLINs and IRS, (2) investigate factors that contributed to whether households received what was planned, and (3) investigate how overall coverage observed in the 2021 MIS compared to the 2018 MIS conducted prior to micro-planning. Methods Households’ receipt of ≥ 1 LLIN, and/or IRS within the past 12 months in the 2021 MIS, was compared against the micro-planning area under which the households fell. GPS points for 3,550 households were overlayed onto digitized micro-planning maps in order to determine what micro-plan the households fell under, and thus whether they received their planned intervention. Mixed-effects regression models were conducted to investigate what factors affected whether these households: (1) received their planned intervention, and (2) received any intervention. Finally, coverage indicators between the 2021 and 2018 MIS were compared. Results Overall, 60.0% (95%CI 55.4, 64.4) of households under a micro-plan received their assigned intervention, with significantly higher coverage of the planned intervention in LLIN-assigned areas (75.7% [95%CI 69.5, 80.9]) compared to IRS-assigned areas (49.4% [95%CI: 44.4, 54.4]). Regression analysis indicated that households falling under the IRS micro-plan had significantly reduced odds of receiving their planned intervention (OR: 0.34 [95%CI 0.24, 0.48]), and significantly reduced odds of receiving any intervention (OR: 0.51 [95%CI 0.37, 0.72] ), compared to households under the LLIN micro-plan. Comparison between the 2021 and 2018 MIS indicated a 27% reduction in LLIN coverage nationally in 2021, while IRS coverage was similar. Additionally, between 2018 and 2021, there was a 13% increase in households that received neither intervention. Conclusions This analysis shows that although the micro-planning strategy adopted in 2020 worked much better for LLIN-assigned areas compared to IRS-assigned areas, there was reduced overall vector control coverage in 2021 compared to 2018 before micro-planning.
Læs mere Tjek på PubMedKamala Thriemer, Tamiru Shibiru Degaga, Michael Christian, Mohammad Shafiul Alam, Megha Rajasekhar, Benedikt Ley, Mohammad Sharif Hossain, Mohammad Golam Kibria, Tedla Teferi Tego, Dagamawie Tadesse Abate, Sophie Weston, Hellen Mnjala, Angela Rumaseb, Ari Winasti Satyagraha, Arkasha Sadhewa, Lydia Vista Panggalo, Lenny L Ekawati, Grant Lee, Rodas Temesgen Anose, Fitsum Getahun Kiros, Julie A Simpson, Amalia Karahalios, Adugna Woyessa, J Kevin Baird, Inge Sutanto, Asrat Hailu, Ric N Price
Lancet, 1.12.2023
Tilføjet 1.12.2023
In patients with a G6PD activity of 70% or greater, high-dose short-course primaquine was safe and relatively well tolerated and reduced the risk of subsequent P vivax parasitaemia within 63 days by five fold. Universal radical cure therefore potentially offers substantial clinical, public health, and operational benefits, but these benefits will vary with endemic setting.
Læs mere Tjek på PubMedMalaria Journal, 30.11.2023
Tilføjet 30.11.2023
Abstract Background Dual hrp2/hrp3 genes deletions in P. falciparum isolates are increasingly reported in malaria-endemic countries and can produce false negative RDT results leading to inadequate case management. Data on the frequency of hrp2/hrp3 deleted parasites are rarely available and it has become necessary to investigate the issue in Burkina Faso. Methods Plasmodium falciparum-positive dried blood spots were collected during a cross-sectional household survey of the malaria asymptomatic children from Orodara, Gaoua, and Banfora. Amplicons from the target regions (exon 2 of hrp2 and hrp3 genes) were generated using multiplexed nested PCR and sequenced according to Illumina’s MiSeq protocol. Results A total of 251 microscopically positive parasite isolates were sequenced to detect hrp2 and hrp3 gene deletions. The proportion of RDTs negative cases among microscopy positive slides was 12.7% (32/251). The highest prevalence of negative RDTs was found in Orodara 14.3% (5/35), followed by Gaoua 13.1%(24/183), and Banfora 9.1% (3/33). The study found that 95.6% of the parasite isolates were wild type hrp2/ hrp3 while 4.4% (11/251) had a single hrp2 deletion. Of the 11 hrp2 deletion samples, 2 samples were RDT negative (mean parasitaemia was 83 parasites/ μL) while 9 samples were RDT positive with a mean parasitaemia of 520 parasites /μL (CI95%: 192–1239). The highest frequency of hrp2 deletion 4/35 (11.4%) was found in Orodara, while it was similar in the other two sites (
Læs mere Tjek på PubMedMalaria Journal, 30.11.2023
Tilføjet 30.11.2023
Abstract Background The Lihir Islands of Papua New Guinea host a mining operation that has resulted in a mine-impacted zone (MIZ) with reduced malaria transmission and a substantial influx of mine employees, informal cross-country traders, returning locals, and visitors. Prevalence of malaria parasites was assessed in travellers arriving on the Lihir Group of Islands to evaluate the risk of parasite importation. Methods In 2018, a cross-sectional study at the airport and main wharf was conducted, targeting asymptomatic travellers who had been away from Lihir for at least 12 days. Microscopy, rapid diagnostic tests (RDTs), and quantitative PCR (qPCR) were used to determine Plasmodium parasite prevalence, employing logistic regression models to identify factors associated with qPCR positivity. Results 398 travellers arriving by plane and 402 arriving by boat were included. Both cohorts were significantly different. Mean age among travellers arriving by plane was 40.1 years (SD ± 10.1), 93% were male and 96% were employed at the mine. In contrast, among travellers arriving by boat, the mean age was 31.7 years (SD ± 14.0), 68% were male and 36% were employed at the mine. The prevalence of malaria infection among travellers arriving by plane was 1% by RDT and microscopy, and increased to 5% by qPCR. In contrast, those arriving by boat showed a prevalence of 8% by RDT and microscopy, and 17% by qPCR. Risk factors for infection were arriving by boat (OR 4.2; 95%CI 2.45,7.21), arriving from nearby provinces with high malaria incidence (OR 5.02; 95%CI 1.80, 14.01), and having been away from Lihir for 91 days or more (OR 4.15; 95%CI 2.58, 6.66). Being mine worker staying at the mine accommodation was related with less infection risk (OR 0.24; 95% CI 0.14, 0.43); while Lihirian residents returning from a trip, VFRs, or people with trading unrelated to mining had higher risks (p = 0.0066). Conclusions Travellers arriving by boat faced increased risk of malaria infection than those arriving by plane. This subpopulation poses an import risk to the MIZ and the rest of Lihir Islands. Screening of high-risk groups at wharfs, and collaboration with nearby Islands, could sustain reduced transmission and facilitate malaria elimination strategies.
Læs mere Tjek på PubMedMunyaradzi Makoni
The Lancet Microbe, 30.11.2023
Tilføjet 30.11.2023
An mRNA vaccine candidate that produces an immune response against malaria parasites in the liver has shown promise in a preclinical study in mice by Mitch Ganley and colleagues.
Læs mere Tjek på PubMedEmilie Guémas, Romain Coppée, Sandie Ménard, Milena du Manoir, Sandrine Nsango, Dieudonné Makaba Mvumbi, Emmanuel Nakoune, Carole Else Eboumbou Moukoko, Marielle Karine Bouyou Akotet, Tatfeng Youtchou Mirabeau, Sylvie Manguin, Doudou Malekita Yobi, Jean Akiana, Lady Charlène Kouna, Denise Patricia Mawili Mboumba, Dominique Fatima Voumbo-Matoumona, Alliance-Laure Otam, Pierre-Alain Rubbo, Jean-Pierre Lombart, Elisabeth Kwanai, Olivia Cohen, Xavier Iriart, Lawrence Ayong, Jean Bernard Lekana-Douki, Frédéric Ariey, Antoine Berry
The Lancet Microbe, 30.11.2023
Tilføjet 30.11.2023
Reduced sulfadoxine–pyrimethamine efficacy due to increased resistance is a worrying situation, especially because the malaria transmission level is high in central Africa. Although the resistance phenotype remains to be confirmed, the emergence and spread of the vagKgs allele in west and central Africa could challenge the use of sulfadoxine–pyrimethamine.
Læs mere Tjek på PubMedMalaria Journal, 28.11.2023
Tilføjet 28.11.2023
Abstract Background The risk of widespread resistance to artemisinin-based combination therapy (ACT) remains high in Uganda following detection of Plasmodium falciparum parasites with delayed artemisinin clearance genotype and phenotype. Establishment of context specific interventions to mitigate emergence and spread of artemisinin resistance is thus key in the fight against malaria in the country. The aim of this study was to explore the experiences of healthcare personnel on malaria diagnosis and self-reported efficacy of ACT in the management of malaria symptomatic patients in hospitals in low and high malaria transmission settings in Uganda. Methods This was a qualitative study in which data was collected from healthcare personnel in hospitals using key informant interviews. The key informant interview guide was developed, pre-tested prior to use and covered the following areas, (i) sociodemographic characteristics, (ii) malaria diagnosis (clinical and parasite based), (iii) quality-assured artemisinin-based combination therapy, (iv) malaria patient follow-up, (v) artemisinin resistance, (vi) anti-malarial self-medication. Data was entered in Atlas.ti ver 9.0 and analysis done following a framework criterion. Results A total of 22 respondents were interviewed of which 16 (72.7%) were clinicians. Majority, 81.8% (18/22) of the respondents were male. The following themes were developed from the analysis, malaria diagnosis (procedures and challenges), use of malaria laboratory test results, malaria treatment in hospitals, use of quality assured ACT (QAACT) in malaria treatment, and efficacy of ACT in malaria treatment. Conclusion Most healthcare personnel-initiated malaria treatment after a positive laboratory test. Cases of malaria patients who report remaining symptomatic after prior use of ACT exist especially in high malaria transmission settings in Uganda. There is need for regular monitoring of artemisinin resistance emergence and spread in the country.
Læs mere Tjek på PubMedMalaria Journal, 28.11.2023
Tilføjet 28.11.2023
Abstract Background Plasmodium vivax is the main species responsible for human malaria in Brazil, and one of its manifestations is splenic malaria, though there are still challenges in its diagnosis. The present study aimed to standardize Plasmodium sp. DNA extraction from histological slices of spleen and diagnosis using real-time qPCR. Methods This study performed a microtomy of a paraffin-embedded spleen as a positive control for P. vivax from a patient who had been previously diagnosed with the parasite. The sample was deparaffinized with xylol and ethanol, then DNA extraction was performed with two commercial kits. qPCR was carried out with the Taqman system for detection of Plasmodium sp. and was made species-specific using PvmtCOX1 gene. From 2015 to 2019, 200 spleen samples were obtained from trauma patients subjected to splenectomy in Manaus, Amazonas. All the samples were tested for cell-free human DNA (cfDNA). Results The deparaffinization and the Plasmodium vivax DNA extraction method was successfully standardized, and the control sample was positive for P. vivax. Of the 200 samples, all qPCRs were negative, but they were positive for human PCR. Conclusion Paraffinization is practical and efficient for the preservation of samples, but the formation of bonds between proteins and DNA makes extraction difficult. Despite this, in this study, it was possible to standardize a method of DNA extraction for detecting P. vivax.
Læs mere Tjek på PubMedMalaria Journal, 28.11.2023
Tilføjet 28.11.2023
Abstract Background Coronavirus disease 2019 (COVID-19) pandemic affected malaria control activities in sub-Saharan Africa (SSA) resulting in 690,000 excess deaths in the year 2021. The authors hypothesized that COVID-19 affected the World Health Organization (WHO) Test, Treat and Track (T3) strategy that has been implemented in Uganda since 2010. In this study, health worker’s adherence to the T3 strategy during COVID-19 pandemic in Eastern Uganda was studied by assessing their knowledge, skills and practices. Methods A cross-sectional study utilizing mixed quantitative and qualitative data collections methods was conducted at Mbale Regional Referral Hospital in Eastern Uganda between November and December in 2020. Data were captured on demographics, knowledge, skills and practices for both health workers (HWs) and patients. Quantitative data were analysed using STATA 15.0 and reported as descriptive statistics, proportions and statistical associations. Moreover, qualitative data were collected via key informant interviews (KII) among purposively sampled study participants and analysed thematically using NVIVO software. Ethical approval was obtained prior to the study. Results A total of 436 study participants, of whom 103/436 (24%) and 333/436 (76%) were HWs and patients, respectively were studied. Among the HWs with mean age of 34 years (SD = 8.8 years), 81/103 (79%) had good practices, most 63/103 (61%) had good knowledge, and only 11/103 (10.7%) had good skills. Specifically, on the cadres, the laboratory personnel 19/103 (18%) had good knowledge 14/19 (74%) OR: 2.0 (95% CI 0.7–6) and were highly skilled OR: 4.6 (95% CI 1.2—18.1; P
Læs mere Tjek på PubMedFrancis N. NkemngoLymen W. RaissaDaniel N. NgueteCyrille NdoJerome Fru-ChoFlobert NjiokouSamuel WanjiCharles S. Wondji1Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon2Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon3Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon4Research Foundation in Tropical Diseases and Environment, Buea, Cameroon5Centre for Infection Biology and Translational Research, Forzi Institute, Buea, Cameroon6Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom, Audrey Odom John
Antimicrobial Agents And Chemotherapy, 27.11.2023
Tilføjet 27.11.2023
Perrine CourletJustin J. WilkinsClaude OeuvrayWei GaoAkash Khandelwal1Merck Institute for Pharmacometrics, Ares Trading S.A., (an affiliate of Merck KGaA, Darmstadt, Germany), Lausanne, Switzerland2Occams Coöperatie UA, Amstelveen, the Netherlands3The Global Health Institute of Merck (an affiliate of Merck KGaA, Darmstadt, Germany), Eysins, Switzerland4EMD Serono Research and Development Institute, Inc., Billerica, Massachusetts, USA5The healthcare business of Merck KGaA, Darmstadt, Germany, Andreas H. Groll
Antimicrobial Agents And Chemotherapy, 27.11.2023
Tilføjet 27.11.2023
Simone DowdNanhua ChenMichelle L. GattonMichael D. EdsteinQin Cheng1Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia2Centre for Immunology and Infection Control, Faculty of Health, Queensland University of Technology, Brisbane, Australia, Audrey Odom John
Antimicrobial Agents And Chemotherapy, 27.11.2023
Tilføjet 27.11.2023
Gauthier Mesia Kahunu, Sarah Wellmann Thomsen, Louise Wellmann Thomsen, Hypolite Muhindo Mavoko, Patrick Mitashi Mulopo, Emma Filtenborg Hocke, Papy Mandoko Nkoli, Vito Baraka, Daniel T.R. Minja, Andria Mousa, Cally Roper, Destin Mbongi Moke, Dieudonné Mumba Ngoyi, Eric Mukomena Sompwe, Jean Jacques Muyembe Tanfum, Helle Hansson, Michael Alifrangis
International Journal of Infectious Diseases, 26.11.2023
Tilføjet 26.11.2023
According to the World Health Organization (WHO), the DRC accounts for 12.3% of global malaria cases and 12.6% of all malaria attributable deaths; in figures this is approximately 30 million cases and almost 80,000 deaths in 2021 [1]. The DRC has implemented a number of control efforts to combat malaria. These include the distribution of insecticide-treated bed nets (ITNs), the use of artemisinin-based combination therapies (ACTs) against uncomplicated malaria (artesunate-amodiaquine [ASAQ] or artemether-lumefantrine [AL]) and intermittent preventive treatment of pregnant women (IPTp) using sulfadoxine-pyrimethamine (SP) [1].
Læs mere Tjek på PubMedMalaria Journal, 26.11.2023
Tilføjet 26.11.2023
Abstract Background Chemoprophylaxis is a prevention method for malaria during travel in malaria-endemic countries. This study aimed to collate and synthesize the evidence of malarial chemoprophylaxis among malaria death cases. Methods Studies documenting malarial chemoprophylaxis related to malaria deaths were searched in PubMed, Scopus, MEDLINE, Embase, and CENTRAL until 3 July 2022. The pooled proportion of malarial chemoprophylaxis among death cases was synthesized using logit transformation and back transformation to a proportion performed using generalized linear mixed models. The pooled log odds ratio (log-OR) with a 95% confidence interval (CI) of malarial chemoprophylaxis in death cases compared to survivors were synthesized. Results Fifty-eight studies were included in the systematic review and the meta-analysis. Of 602 pooled malaria death cases, the number of patients who took chemoprophylaxis was 187 (30%) (95% CI 22–40, P
Læs mere Tjek på PubMedRosauro Varo, Valerie M. Crowley, Humberto Mucasse, Antonio Sitoe, Justina Bramugy, Lena Serghides, Andrea M. Weckman, Clara Erice, Rubao Bila, Pio Vitorino, Campos Mucasse, Marta Valente, Sara Ajanovic, Núria Balanza, Kathleen Zhong, Yiovanna Derpsch, Melissa Gladstone, Alfredo Mayor, Quique Bassat, Kevin C. Kain
International Journal of Infectious Diseases, 26.11.2023
Tilføjet 26.11.2023
In 2021 malaria caused ∼247 million clinical episodes, 2-4 million cases of severe disease and an estimated 619,000 deaths [1]. The highest mortality rates occur in sub-Saharan African children under the age of five.
Læs mere Tjek på PubMedMalaria Journal, 24.11.2023
Tilføjet 24.11.2023
Abstract Background Malaria is transmitted by different Anopheles species. In Brazil, the disease is concentrated in the Amazon region. Rivers play an important role in the life cycle of malaria since the vector reproduces in aquatic environments. The waters of the rivers in the Amazon have distinct chemical characteristics, which affect the colour of the water and therefore, the study analysed whether the colour of the waters of the rivers have an on influence the distribution of malaria. The goal of the study was to correlate the different colourations of the water (black, white and mixed water) and the malaria incidence in 50 municipalities of the Amazonas state, Brazil, and then test hypotheses about the characteristics of the colour of the rivers and disease incidence. Methods This study was conducted for a period of seventeen years (2003–2019) in 50 municipalities in the state of Amazonas, Brazil. A conditionally Gaussian dynamic linear model was developed to analyse the association of malaria incidence and three types of river colour: white, black and mixed. Results The analyses indicate that the distribution of malaria is related to the colouration of the rivers. The results showed that places located near black-water rivers have a higher malaria incidence when compared to places on the banks of white-water rivers. Conclusions Historically, the hydrological regime has played an important role in the dynamics of malaria in the Amazon, but little is known about the relationship between river colours and the incidence of the disease. This research was carried out in a region with hydrographic characteristics that were heterogeneous enough to allow an analysis that contrasted different colours of the rivers and covered almost the whole of the state of Amazonas. The results help to identify the places with the highest risk of malaria transmission and it is believed that they will be able to contribute to more precise planning of actions aimed at controlling the disease in the region.
Læs mere Tjek på PubMedShih-Che Weng, Reem A. Masri, Omar S. Akbari
Trends in Parasitology, 24.11.2023
Tilføjet 24.11.2023
Mosquito-borne illnesses represent a significant global health peril, resulting in approximately one million fatalities annually. West Nile, dengue, Zika, and malaria are continuously expanding their global reach, driven by factors that escalate mosquito populations and pathogen transmission. Innovative control measures are imperative to combat these catastrophic ailments. Conventional approaches, such as eliminating breeding sites and using insecticides, have been helpful, but they face challenges such as insecticide resistance and environmental harm. Given the mounting severity of mosquito-borne diseases, there is promise in exploring innovative approaches using synthetic biology to bolster mosquitoes\' resistance to pathogens, or even eliminate the mosquito vectors, as a means of control. This review outlines current strategies, future goals, and the importance of gene editing for global health defenses against mosquito-borne diseases.
Læs mere Tjek på PubMedRabe, A. P. J., Loke, W. J., Kalyani, R. N., Tummala, R., Stirnadel-Farrant, H. A., Were, J., Winthrop, K. L.
BMJ Open, 22.11.2023
Tilføjet 22.11.2023
ObjectivesDetermine the prevaccination healthcare impact of COVID-19 in patients with systemic lupus erythematosus (SLE) in England. DesignRetrospective cohort study of adult patients with SLE from 1 May to 31 October 2020. SettingClinical Practice Research Datalink (CPRD) Aurum and Hospital Episode Statistics (HES) databases from general practitioners across England combining primary care and other health-related data. ParticipantsOverall, 6145 adults with confirmed SLE diagnosis ≥1 year prior to 1 May 2020 were included. Most patients were women (91.0%), white (67.1%), and diagnosed with SLE at age
Læs mere Tjek på PubMedMalaria Journal, 22.11.2023
Tilføjet 22.11.2023
Abstract Background Malaria remains the leading cause of mortality and morbidity in young children in sub-Saharan Africa. To prevent malaria in children living in moderate-to-high malaria transmission areas, the World Health Organization has recommended perennial malaria chemoprevention (PMC). Prior to piloting PMC implementation in southern Togo, a household survey was conducted to estimate malaria infection prevalence in children under 2 years of age (U2). Methods A cross-sectional community-based household survey was conducted in the Haho district in the Togo Plateaux region. A three-stage random sampling method was used to select study participants aged 10–23 months whose caretakers gave informed consent. The prevalence of Plasmodium infection, defined as a positive rapid diagnostic test (RDT), was estimated with 95% confidence interval (CI). Clinical malaria was defined as having a positive RDT plus fever (≥ 37.5 °C) or history of fever in the last 24 h. Mixed-effects logistic regression models were used to assess the child’s, caretaker’s, and household’s factors associated with malaria infection. Results A total of 685 children were included in the survey conducted January–February in 2022 (dry season). Median age was 17 months (interquartile range: 13–21). About 80% of the children slept under a bed net the night before the interview. Malaria infection prevalence was 32.1% (95% CI 27.7–37.0) with significant area variation (cluster range: 0.0–73.3). Prevalence of clinical malaria was 15.4% (95% CI 12.2–19.2). Children whose caretakers were animist (aOR: 1.71, 95% CI 1.19–2.46) and those living in mother-headed households (aOR: 2.39, 95% CI 1.43–3.99) were more likely to have a positive RDT. Living more than 5 km away from the nearest health facility (aOR: 1.60, 95% CI 1.04–2.44) and presence of two or more under-5-years children in the household (aOR: 1.44, 95% CI 1.01–2.07) were also associated with increased risk of infection. Conclusion One-third of the children U2 who participated in this survey had malaria infection, thus PMC could be a promising strategy to reduce malaria burden in young children in Plateaux region. Reinforcement of outreach services and targeting the poorest households should be prioritized to reduce the inequity in malaria prevention in children exposed to the infection.
Læs mere Tjek på PubMedMalaria Journal, 22.11.2023
Tilføjet 22.11.2023
Abstract Background Geostatistical analysis of health data is increasingly used to model spatial variation in malaria prevalence, burden, and other metrics. Traditional inference methods for geostatistical modelling are notoriously computationally intensive, motivating the development of newer, approximate methods for geostatistical analysis or, more broadly, computational modelling of spatial processes. The appeal of faster methods is particularly great as the size of the region and number of spatial locations being modelled increases. Methods This work presents an applied comparison of four proposed ‘fast’ computational methods for spatial modelling and the software provided to implement them—Integrated Nested Laplace Approximation (INLA), tree boosting with Gaussian processes and mixed effect models (GPBoost), Fixed Rank Kriging (FRK) and Spatial Random Forests (SpRF). The four methods are illustrated by estimating malaria prevalence on two different spatial scales—country and continent. The performance of the four methods is compared on these data in terms of accuracy, computation time, and ease of implementation. Results Two of these methods—SpRF and GPBoost—do not scale well as the data size increases, and so are likely to be infeasible for larger-scale analysis problems. The two remaining methods—INLA and FRK—do scale well computationally, however the resulting model fits are very sensitive to the user’s modelling assumptions and parameter choices. The binomial observation distribution commonly used for disease prevalence mapping with INLA fails to account for small-scale overdispersion present in the malaria prevalence data, which can lead to poor predictions. Selection of an appropriate alternative such as the Beta-binomial distribution is required to produce a reliable model fit. The small-scale random effect term in FRK overcomes this pitfall, but FRK model estimates are very reliant on providing a sufficient number and appropriate configuration of basis functions. Unfortunately the computation time for FRK increases rapidly with increasing basis resolution. Conclusions INLA and FRK both enable scalable geostatistical modelling of malaria prevalence data. However care must be taken when using both methods to assess the fit of the model to data and plausibility of predictions, in order to select appropriate model assumptions and parameters.
Læs mere Tjek på PubMedMalaria Journal, 21.11.2023
Tilføjet 21.11.2023
Abstract Background Malaria is a leading cause of death and reduced life span in Guinea and Sierra Leone, where plans for rolling out the malaria vaccine for children are being made. There is little evidence about caregiver acceptance rates to guide roll-out policies. To inform future vaccine implementation planning, this analysis aimed to assess potential malaria vaccine acceptance by caregivers and identify factors associated with acceptance in Guinea and Sierra Leone. Methods A cross-sectional household survey using lot quality assurance sampling was conducted in three regions per country between May 2022 and August 2022. The first survey respondent in each household provided sociodemographic information. A household member responsible for childcare shared their likelihood of accepting a malaria vaccine for their children under 5 years and details about children’s health. The prevalence of caregiver vaccine acceptance was calculated and associated factors were explored using multivariable logistic regression modelling calculating adjusted odds ratios (aOR) with 95% confidence intervals (CI). Results Caregivers in 76% of 702 sampled households in Guinea and 81% of 575 households in Sierra Leone were accepting of a potential vaccine for their children. In both countries, acceptance was lower in remote areas than in urban areas (Guinea: aOR 0.22 [95%CI 0.09–0.50], Sierra Leone: 0.17 [0.06–0.47]). In Guinea, acceptance was lower among caregivers living in the richest households compared to the poorest households (0.10 [0.04–0.24]), among those whose children were tested for malaria when febrile (0.54 [0.34–0.85]) and in households adopting more preventative measures against malaria (0.39 [0.25–0.62]). Better knowledge of the cause of malaria infection was associated with increased acceptance (3.46 [1.01–11.87]). In Sierra Leone, vaccine acceptance was higher among caregivers living in households where the first respondent had higher levels of education as compared to lower levels (2.32 [1.05–5.11]). Conclusion In both countries, malaria vaccine acceptance seems promising for future vaccine roll-out programmes. Policy makers might consider regional differences, sociodemographic factors, and levels of knowledge about malaria for optimization of implementation strategies. Raising awareness about the benefits of comprehensive malaria control efforts, including vaccination and other preventive measures, requires attention in upcoming campaigns.
Læs mere Tjek på PubMedMalaria Journal, 20.11.2023
Tilføjet 20.11.2023
Abstract Background Ultrasensitive rapid diagnostic test (usRDT) was recently developed to improve the detection of low-density Plasmodium falciparum infections. However, its diagnostic performance has not been evaluated in the Democratic Republic of Congo (DRC). This study aims to determine the performance of the usRDT in malaria diagnosis in asymptomatic individuals under field condition in Kisangani, Northeast of DRC. Methods A community-based cross-sectional study was carried out from June to August 2022 on 312 asymptomatic individuals residing in the city of Kisangani. Capillary blood samples were collected by finger prick for microscopic examination of thick and thin blood film, RDTs, and nested polymerase chain reaction (PCR). Alere™ Malaria Ag P.f usRDT and conventional RDT (cRDT/SD Bioline Malaria Ag P.f) kits were used for the detection of Plasmodium histidine rich protein 2 (HRP2) antigen as a proxy for the presence of P. falciparum. The diagnostic performance of the usRDT was compared with cRDT, microscopy and PCR. Results The prevalence of asymptomatic P. falciparum malaria was 40.4%, 42.0%, 47.1% and 54.2% by cRDT, microscopy, usRDT and PCR, respectively. By using PCR as a reference, usRDT had sensitivity and specificity of 87.0% (95% CI 81.4–91.7) and 100.0% (95% CI 97.5–100.0), respectively, whereas the cRDT had sensitivity and specificity of 74.6% (95% CI 67.3–80.9) and 100% (95% CI 97.1–100.0), respectively. By using microscopy as a reference, usRDT had sensitivity and specificity of 96.9% (95% CI 92.4–99.2) and 89.0% (95% CI 83.5–93.1), respectively, while the cRDT had sensitivity and specificity of 96.2% (95% CI 92.3–98.7) and 100% (95% CI 97.9–100.0), respectively. Conclusion The usRDT showed better diagnostic performance with higher sensitivity than the cRDT which is currently in use as point-of-care test. Further research is necessary to assess the access and cost-effectiveness of the usRDTs to use for malaria surveillance.
Læs mere Tjek på PubMedBMC Infectious Diseases, 18.11.2023
Tilføjet 18.11.2023
Abstract Malaria has not yet been eradicated in Iran, and Plasmodium vivax (P. vivax) is the main cause of malaria in the country. This study aimed to investigate and analyze the amount of genetic diversity of Plasmodium vivax merozoite surface protein-5 (PvMSP-5) exon 1 gene in the southeast of Iran. Thirty-five patients with clinical symptoms of P. vivax malaria participated. The exon 1 of PvMSP-5 was amplified by PCR, and the PCR product of all isolates was sequenced, and genetic polymorphisms were determined using various genetic software. The analysis showed that studied isolates are different from one another in the DnaSP software version. Out of the 612 sites, 477 were monomorphic and 135 were segregated. The total number of mutations was 143. The singleton variable and the parsimony informative sites were 23 and 112, respectively. There were 17 specific haplotypes with haplotype diversity equal to 0.943. Nucleotide diversity was equal to 0.06766 in the isolates. The ratio of nonsynonymous (0.06446) to synonymous (0.07909) mutations was 0.815020. Tajima’s D, which expressed coding, and non-coding regions, was 0.72403, which was not deemed significant (P > 0.10). The analysis of intrapopulation diversity revealed nucleotide and haplotype diversity in the msp-5 gene of Iranian P. vivax isolates. In addition to balancing or purifying selection, intragenic recombination also contributed to the variation observed in exon 1 of PvMSP-5, according to the findings.
Læs mere Tjek på PubMedMalaria Journal, 17.11.2023
Tilføjet 17.11.2023
Abstract Background Karnataka is one of the largest states in India and has a wide range of geographical terrains, ecotypes, and prevalence of malaria. It experiences a voluminous influx and efflux of people across the state that affects the spread of malaria. The state deployed focused intervention measures keeping the national objective of malaria elimination as the foremost priority. This brought down malaria cases below a thousand by the year 2021. Furthermore, the state is motivated toward malaria elimination by 2025. This study analyzes the trends in malaria indices over the past three decades in the state and highlights the key intervention measures that impacted the reduction in the malaria burden. Methods Data from 1991 to 2021 at the district level was collected from the archives of Regional Office for Health & Family Welfare (ROH&FW), Bangalore. Time-tend analysis on this data was conducted after categorization into three decades. Sequence plots were then plotted on the moving average of Annual Parasite Index for all those three decades. Generalized estimating equation model with Poisson distribution were used to evaluate difference in these indicators with pre and post interventions like LLIN, RDT with ACT and Guppy and Gambusia fishes. Results Malaria burden across the state has consistently declined over the last three decades with few years of exception. This has coincided with the mortality also steadily declining from 2006 and culminating in zero malaria deaths reported from 2011 to 2019. Morbidity had drastically reduced from the hundred-thousand (1993–2003) to ten thousand (2004–2016) thousands (2017–2020) of cases in this period and less than thousand cases were reported by 2021. Generalized estimating equation (GEE) model revealed significant difference of incidence risk ratio of malaria incidence and deaths, post introduction of interventions like LLIN, RDT with ACT and Guppy and Gambusia fishes, indicating these three as important interventions for reducing the malaria burden. Time trend analysis revealed a linear decreasing trend in malaria cases during 2011–2021 decade. Conclusions A linear decreasing trend in malaria cases was observed during 2011–2021 decade. LLIN, RDT with ACT and Guppy and Gambusia fish’s interventions significantly helped in reducing the state malaria burden.
Læs mere Tjek på PubMedBMC Infectious Diseases, 17.11.2023
Tilføjet 17.11.2023
Abstract Malaria is a significant global health concern, with a majority of cases in Sub-Saharan African nations. Numerous antimalarial drugs have been developed to counter the rampant prevalence of Plasmodium falciparum malaria. Artemisinin-based Combination Therapy (ACT) has served as the primary treatment of uncomplicated malaria in Ghana since 2005. However, a growing concern has emerged due to the escalating reports of ACT resistance, particularly in Southeast Asia, and its encroachment into Africa. Specifically, mutations in the Kelch propeller domain on chromosome 13 (Pfk13) have been linked to ACT resistance. Yet, our understanding of mutation prevalence in Africa remains largely uncharted. In this study, we compared Pfk13 sequences obtained from 172 P. falciparum samples across three ecological and transmission zones in Ghana. We identified 27 non-synonymous mutations among these sequences, of which two of the mutations, C580Y (found in two samples from the central region) and Y493H (found in one sample from the north), had previously been validated for their association with artemisinin resistance, a phenomenon widespread in Southeast Asia. The Pfk13 gene diversity was most pronounced in the northern savannah than the central forest and south coastal regions, where transmission rates are lower. The observed mutations were not significantly associated with geographical regions, suggesting a frequent spread of mutations across the country. The ongoing global surveillance of artemisinin resistance remains pivotal, and our findings provides insights into the potential spread of resistant parasites in West Africa. Furthermore, the identification of novel codon mutations in this study raises their potential association to ACT resistance, warranting further investigation through in vitro assays to ascertain their functional significance.
Læs mere Tjek på PubMedMalaria Journal, 16.11.2023
Tilføjet 16.11.2023
Abstract Background Irrigated rice cultivation in sub-Saharan Africa not only brings more malaria vectors to nearby communities, but also greater malaria risk. To aid the implementation of mosquito control in rice-growing communities, it is necessary to understand how farmers understand, view and manage their responsibility in mosquito generation and whether they are interested in coordinating to minimize it. Methods Qualitative methods (observation grids, semi-structured in-depth interviews and focus group discussions) were used to reveal the perceptions of mosquitoes and their control in two irrigated rice farming communities in central Côte d’Ivoire near the M’bé and Lokapli irrigation schemes. Results All rice farmers viewed mosquitoes as severe nuisances, and most acknowledged that they caused djèkouadjo (malaria) and were less numerous during harmattan (dry season). Many study participants believed that mosquitoes originated from grasses and stagnant water around villages. Only those living closer in proximity (~ 1 km) to the paddies believed that mosquitoes came from the bas-fonds (irrigated lowlands). However, they did not associate mosquito production with rice cultivation. Some farmers believed that there were more mosquitoes in recent years than historically because of the dam construction, but remarked on the importance of the dam (and bas-fonds) for their livelihood. Many farmers were not convinced that mosquito control could occur at farm-level. Conclusions To enhance accountability amongst rice farmers, there is a need for greater awareness on the rice-mosquito link, and emphasis that the link does not imply a trade-off between food production and health. Training should not only be directed towards farming communities, but also agricultural and health extension workers. Future riceland mosquito control methods must focus on improving crop productivity and address collective action problems that may occur.
Læs mere Tjek på PubMedMalaria Journal, 16.11.2023
Tilføjet 16.11.2023
Abstract Background Microscopy continues to be the mainstay for the evaluation of parasitaemia in malaria but requires laboratory support and microbiological experience. Other fast and simple methods are necessary. Methods A retrospective observational study of imported malaria treated from July-2007 to December-2020 was carried out to evaluate the association between the degree of parasitaemia and both rapid diagnostic tests (RDT) reactivity patterns and haematological parameters. Plasmodium falciparum monoinfections diagnosed by peripheral blood smear and/or polymerase chain reaction (PCR),which also had a positive RDT result in the same blood sample, were included in the study. Results A total of 273 patients were included. Most of them were male (n = 256; 93.8%) and visiting friends and relatives (VFR) travellers (n = 252; 92.3%). Patients with plasmodial lactate dehydrogenase (pLDH) or aldolase and histidine-rich protein 2 (HRP-2) co-reactivity (Pan/Pf pattern) had a parasitaemia range between 0 and 37% while those with just HRP-2 reactivity (P. falciparum pattern) had ranges between 0 and 1%. Not a single case of P. falciparum pattern was found for parasitaemia ranges greater than 1%, showing a negative predictive value of 100% for high parasitaemia. All the correlations between haematological parameters and parasitaemia resulted to be weak, with a maximum rho coefficient of -0.35 for lymphocytes and platelets, and of 0.40 for neutrophils-to-lymphocytes count ratio. Multivariate predictive models were constructed reflecting a poor predictive capacity. Conclusions The reactivity pattern of RDT allows a rapid semi-quantitative assessment of P. falciparum parasitaemia in travellers with imported malaria, discriminating patients with lower parasite loads. Haematological parameters were not able to estimate parasitaemia with sufficient precision.
Læs mere Tjek på PubMedSimone DowdNanhua ChenMichelle L. GattonMichael D. EdsteinQin Cheng1Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia2Centre for Immunology and Infection Control, Faculty of Health, Queensland University of Technology, Brisbane, Australia, Audrey Odom John
Antimicrobial Agents And Chemotherapy, 16.11.2023
Tilføjet 16.11.2023
Malaria Journal, 16.11.2023
Tilføjet 16.11.2023
Abstract Background Water resource development projects are essential for increasing agricultural productivity and ensuring food security. However, these activities require the modification of pre-existing environmental settings, which may alter mosquito larval habitat availability and seasonality. The intensive utilization of current adult vector control tools results in insecticide resistance among the main vectors. When coupled with behavioural resistances, a shift in malaria vector feeding and resting behaviours could compromise the effectiveness of the current adult vector control strategies. Thus, it is important to look for new or alternative vector control interventions for immatures to complement adult control by focusing on different larval habitats and their seasonal availability. Thus, this study investigated larval habitat seasonality and seasonal larval abundance and distribution in irrigated sugar cane plantation settings in Ethiopia. Methods Anopheles mosquito larval habitats were surveyed and visited twice a month for a period of 14 months. Anopheline larvae and pupae were collected, reared, and fed finely ground fish food. Adults were provided with sucrose solution and kept under standard conditions. Female Anopheles mosquitoes were identified morphologically and using a species-specific PCR assay. Environmental parameters, which include habitats’ physico-chemical characteristics, were assessed. Larval habitat diversity and larval abundance and distribution were determined across different seasons. Results The study revealed that Anopheles gambiae sensu lato (s.l.) was the most predominant 4197(57%) vector species, followed by Anopheles coustani complex 2388 (32.8%). Molecular analysis of sub-samples of An. gambiae s.l. resulted in Anopheles arabiensis (77.9%) and Anopheles amharicus (21.5%), and the remaining 1.1% (n = 7) sub-samples were not amplified. Physico-chemical parameters such as temperature (t = 2.22, p = 0.028), conductivity (t = 3.21, p = 0.002), dissolved oxygen (t = 7.96, p = 0.001), nitrate ion (t = 2.51, p = 0.013), and ammonium ion (t = 2.26, p = 0.025) showed a significant and direct association with mosquito larval abundance. Furthermore, mosquito larval abundance was correlated with distance to the nearest houses (r = − 0.42, p = 0.001), exposure to sunlight (r = 0.34, p = 0.001), during long and short rainy season animal hoof prints, truck tires/road puddles and rain pools were negatively correlated (r = − 0.22, p = 0.01) and types of habitat (r = − 0.20, p = 0.01). Significant habitat type productivity were observed in man-made pools (t = 3.881, P = 0.01163), rain pools, animal hoof prints, (t = − 4.332, P = 0.00749 in both short and long rainy season, whereas, during dry seasons habitat type productivity almost similar and have no significance difference. Conclusion The study found that different larval habitats had variable productivity in different seasons, and that physical and physicochemical features like ammonium and nitrate, as well as the distance between larval habitats and households, are related to larval production. As a result, vector control should take into account the seasonality of Anopheles larval habitat as well as the impact of pesticide application on larval source management.
Læs mere Tjek på PubMedPerrine CourletJustin J. WilkinsClaude OeuvrayWei GaoAkash Khandelwal1Merck Institute for Pharmacometrics, Ares Trading S.A., (an affiliate of Merck KGaA, Darmstadt, Germany), Lausanne, Switzerland2Occams Coöperatie UA, Amstelveen, the Netherlands3The Global Health Institute of Merck (an affiliate of Merck KGaA, Darmstadt, Germany), Eysins, Switzerland4EMD Serono Research and Development Institute, Inc., Billerica, Massachusetts, USA5The healthcare business of Merck KGaA, Darmstadt, Germany, Andreas H. Groll
Antimicrobial Agents And Chemotherapy, 15.11.2023
Tilføjet 15.11.2023
Malaria Journal, 15.11.2023
Tilføjet 15.11.2023
Abstract Background The pregnant woman, the fetus, and the newborn child are all at risk from malaria infection in sub-Saharan Africa. Employing insecticide-treated mosquito nets (ITNs) is one of the most efficient methods for avoiding malaria among expectant mothers. However, there is no literature that describes ITN use among pregnant women in East Africa or the contributing factors. Therefore, this study sought to identify the factors affecting pregnant women’s ITN utilization in East Africa. Methods The most recent DHS (Demographic and Health Survey) data for the 11 East African countries from 2011 to 2022 was used. 13,729 pregnant women were examined. To identify factors associated with ITN use, a binary and multiple logistic regression model was built. Variables having a p-value of less than or equal to 0.2 in the binary logistic regression analysis were taken into consideration for the multivariable analysis. In the multiple logistic regression analysis, the adjusted Odds Ratio (aOR) with the 95% Confidence Interval (CI) was provided to proclaim the statistical significance and degree of correlation. Results The survey found that just 47.05% (95% CI 46.21, 47.88) of pregnant mothers reported using ITNs. The highest and lowest values were seen in Uganda (64.13%) and Zimbabwe (6.08%). Women age 25-34y (aOR = 1.19; 95% CI 1.11, 1.29), 35–49y (aOR = 1.26; 95% CI 1.13, 1.41) as compared to 15–24 years, poorer (aOR = 1.15; 95% CI 1.04–1.27), middle (aOR = 1.21; 95% CI 1.09, 1.35), and rich (aOR = 1.18; 95% CI 1.06, 1.31) wealth indexes as compared to poorest, having > 5 family size (AOR = 0.84; 95% CI 0.78, 0.91) primary (aOR = 1.49; 95% CI 1.36, 1.65), and secondary/higher education (aOR = 1.52; 95% CI 1.35, 1.70) as compared to not educated, and married women (aOR = 1.64; 95% CI 1.44, 1.86) have shown a statistically significant association with ITN utilization among pregnant women. Conclusion With a variety of risk variables, including age, wealth, family size, and education, pregnant women in East Africa rarely use ITNs. There is a need to create and strengthen malaria prevention programmes, especially among pregnant women who do not use ITNs, based on the variables mentioned.
Læs mere Tjek på PubMedAndrea Du Toit
Nat Rev Microbiol, 14.11.2023
Tilføjet 14.11.2023
Malaria Journal, 14.11.2023
Tilføjet 14.11.2023
Abstract Background The overlap in the epidemiology of malaria and helminths has been identified as a potential area to exploit for the development of an integrated control strategy that may help to achieve elimination of malaria and helminths. A randomized, controlled, observer-blind trial was conducted to assess the feasibility and safety of combining mass drug administration (MDA) for schistosomiasis and soil transmitted helminths (STH) with seasonal malaria chemoprevention (SMC) among children living in Senegal. Methods Female and male children aged 1–14 years were randomized 1:1:1, to receive Vitamin A and Zinc on Day 0, followed by SMC drugs (sulfadoxine-pyrimethamine and amodiaquine) on Days 1–3 (control group); or praziquantel and Vitamin A on Day 0, followed by SMC drugs on Days 1–3 (treatment group 1); or albendazole and praziquantel on Day 0, followed by SMC drugs on Days 1–3 (treatment group 2). Safety assessment was performed by collecting adverse events from all children for six subsequent days following administration of the study drugs. Pre- and post-intervention, blood samples were collected for determination of haemoglobin concentration, malaria microscopy, and PCR assays. Stool samples were analyzed using Kato-Katz, Merthiolate-iodine-formalin and PCR methods. Urine filtration, PCR and circulating cathodic antigen tests were also performed. Results From 9 to 22 June 2022, 627 children aged 1–14 years were randomized into the three groups described above. Mild, transient vomiting was observed in 12.6% (26/206) of children in treatment group 2, in 10.6% (22/207) in group 1, and in 4.2% (9/214) in the control group (p = 0.005). Pre-intervention, the geometric mean value of Plasmodium falciparum parasite density was highest among children who received albendazole, praziquantel with SMC drugs. Post-intervention, the parasite density was highest among children who received SMC drugs only. Children who received praziquantel and SMC drugs had a lower risk of developing severe anaemia than their counterparts who received SMC drugs alone (OR = 0.81, 95% CI 0.13–5.00, p = 0.63). Conclusions Integration of MDA for helminths with SMC drugs was safe and feasible among Senegalese children. These findings support further evaluation of the integrated control model. Trial registration: The study is registered at Clinical Trial.gov NCT05354258.
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