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47 ud af 47 tidsskrifter valgt, søgeord (malaria) valgt, emner højest 180 dage gamle, sorteret efter nyeste først.
352 emner vises.
Malaria Journal, 17.12.2023
Tilføjet 17.12.2023
Abstract Background Malaria is still endemic in South Korea. However, limited information is available on the current Anopheles breeding sites and the occurrence of insecticide resistance-associated genetic mutations and their distribution needed to control the malaria vector efficiently. Methods This study explored breeding sites of Anopheline adults in Gimpo-si, near the demilitarized zone (DMZ) in Gyeonggi-do province, South Korea, from 2022 to 2023. Genetic diversity was investigated based on the internal transcribed spacer (ITS2), cytochrome c oxidase subunit I (COI), and knockdown resistance (kdr) genes of Anopheles mosquitoes. A natural environment associated with the seasonal abundance of Anopheles larvae was characterized. Results Two breeding sites of Anopheles larvae and adults were found at a stream margin or shallow freshwater near the forest in Wolgot-myeon in Gimpo-si without cattle shed within 1 km and in Naega-myeon in Ganghwa-gun with cow shed within 100 m in 2022 and 2023, respectively. Both sites were located between the newly cultivated lands and the forest. Besides, both breeding sites were in the valley at a slight elevation of 60–70 m from ground lands and maintained the shadow all day. Overall, the Wolgot-myeon breeding site showed various Anopheles spp. larvae, including Anopheles sinensis. Naega-myeon, an additional breeding site found in 2023, had Anopheles sineroides larvae, and approximately 59.7% (89/149) of An. sinensis adults inhabited within a 100-m distance. The total collection, including larvae and adults, revealed that An. sinensis, Anopheles pullus, Anopheles kleini, An. sineroides, Anopheles belenrae, and Anopheles lindesayi accounted for 44.2% (118/267), 0.7% (2/267), 0.7% (2/267), 22.1% (59/267), 1.9% (5/267), and 30.3% (81/267), respectively. Furthermore, various kdr mutant genotypes (F/F, C/C, L/F, L/C and F/C) in An. sinensis, and the first kdr allele mutant (L/F1014) in An. belenrae were identified in South Korea. Conclusions Two breeding sites of Anopheles larvae were studied in Wolgot-myeon and Naega-myeon. Various Anopheles spp. larvae were detected in both habitats, but overall, An. sinensis was the most prevalent adults in both study sites. The occurrence of kdr allele mutant of An. belenrae in South Korea was reported. Rigorous larvae monitoring of Anopheles spp., continuously updating information on Anopheles breeding sites, and understanding the environmental conditions of Anopheles habitats are required to develop an effective malaria control programme in South Korea.
Læs mere Tjek på PubMedLucien Platon, Didier Ménard
Trends in Parasitology, 16.12.2023
Tilføjet 16.12.2023
Malaria is a life-threatening tropical disease caused by parasites of the genus Plasmodium, of which Plasmodium falciparum is the most lethal. Malaria parasites have a complex life cycle, with stages occurring in both the Anopheles mosquito vector and human host. Ring stages are the youngest form of the parasite in the intraerythrocytic developmental cycle and are associated with evasion of spleen clearance, temporary growth arrest (TGA), and drug resistance. This formidable ability to survive and develop into mature, sexual, or growth-arrested forms demonstrates the inherent population heterogeneity. Here we highlight the role of the ring stage as a crossroads in parasite development and as a reservoir of surviving cells in the human host via TGA survival mechanisms.
Læs mere Tjek på PubMedMalaria Journal, 16.12.2023
Tilføjet 16.12.2023
Abstract In many studies to evaluate the quality of malaria diagnosis, microscopy or rapid diagnostic tests (RDT) are compared to PCR. Depending on the method for sample collection and storage (whole blood or dried blood spot), volume of blood used for extraction, volume of DNA used as PCR template, and choice of PCR target (single vs. multi-copy gene), the limit of detection (LOD) of PCR might not exceed the LOD of expert microscopy or RDT. One should not assume that PCR always detects the highest number of infections.
Læs mere Tjek på PubMedLesego, A., Tsegaye, T., Were, L. P. O., Sakvarelidze, G., Garg, S., Morrison, L., Nigussie, S., Githendu, P., Achoki, T.
BMJ Open, 15.12.2023
Tilføjet 15.12.2023
ObjectiveThe Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund) partnered with the Ethiopian Pharmaceutical Supply Agency (EPSA) in 2018–2019 to reform procurement and supply chain management (PSCM) procedures within the Ethiopian healthcare system. This assessment sought to determine the impact of the reforms and document the lessons learnt. DesignMixed-methods study incorporating qualitative and quantitative analysis. Purposive and snowballing sampling techniques were applied for the qualitative methods, and the data collected was transcribed in full and subjected to thematic content analysis. Descriptive analysis was applied to quantitative data. SettingThe study was based in Ethiopia and focused on the EPSA operations nationally between 2017 and 2021. ParticipantsTwenty-five Ethiopian healthcare decision-makers and health workers. InterventionGlobal Fund training programme for health workers and infrastructural improvements OutcomesOperational and financial measures for healthcare PSCM. ResultsThe availability of antiretrovirals, tuberculosis and malaria medicines, and other related commodities, remained consistently high. Line fill rate and forecast accuracy were average. Between 2018 and 2021, procurement lead times for HIV and malaria-related orders reduced by 43.0% relative to other commodities that reported an increase. Many interview respondents recognised the important role of the Global Fund support in improving the performance of EPSA and provided specific attributions to the observed successes. However, they were also clear that more needs to be done in specific critical areas such as financing, strategic reorganisation, data and information management systems. ConclusionThe Global Fund-supported initiatives led to improvements in the EPSA performance, despite several persistent challenges. To sustain and secure the gains achieved so far through Global Fund support and make progress, it is important that various stakeholders, including the government and the donor community, work together to support EPSA in delivering on its core mandate within the Ethiopian health system.
Læs mere Tjek på PubMedJeanne Rini Poespoprodjo, Nicholas M Douglas, Daniel Ansong, Steven Kho, Nicholas M Anstey
Lancet, 15.12.2023
Tilføjet 15.12.2023
Malaria is resurging in many African and South American countries, exacerbated by COVID-19-related health service disruption. In 2021, there were an estimated 247 million malaria cases and 619 000 deaths in 84 endemic countries. Plasmodium falciparum strains partly resistant to artemisinins are entrenched in the Greater Mekong region and have emerged in Africa, while Anopheles mosquito vectors continue to evolve physiological and behavioural resistance to insecticides. Elimination of Plasmodium vivax malaria is hindered by impractical and potentially toxic antirelapse regimens.
Læs mere Tjek på PubMedMalaria Journal, 15.12.2023
Tilføjet 15.12.2023
Abstract Background Plasmodium knowlesi is an established experimental model for basic and pre-clinical malaria vaccine research. Historically, rhesus macaques have been the most common host for malaria vaccine studies with P. knowlesi parasites. However, rhesus are not natural hosts for P. knowlesi, and there is interest in identifying alternative hosts for vaccine research. The study team previously reported that pig-tailed macaques (PTM), a natural host for P. knowlesi, could be challenged with cryopreserved P. knowlesi sporozoites (PkSPZ), with time to blood stage infection equivalent to in rhesus. Here, additional exploratory studies were performed to evaluate PTM as potential hosts for malaria vaccine studies. The aim was to further characterize the parasitological and veterinary health outcomes after PkSPZ challenge in this macaque species. Methods Malaria-naïve PTM were intravenously challenged with 2.5 × 103 PkSPZ and monitored for blood stage infection by Plasmodium 18S rRNA RT-PCR and thin blood smears. Disease signs were evaluated by daily observations, complete blood counts, serum chemistry tests, and veterinary examinations. After anti-malarial drug treatment, a subset of animals was re-challenged and monitored as above. Whole blood gene expression analysis was performed on selected animals to assess host response to infection. Results In naïve animals, the kinetics of P. knowlesi blood stage replication was reproducible, with parasite burden rising linearly during an initial acute phase of infection from 6 to 11 days post-challenge, before plateauing and transitioning into a chronic low-grade infection. After re-challenge, infections were again reproducible, but with lower blood stage parasite densities. Clinical signs of disease were absent or mild and anti-malarial treatment was not needed until the pre-defined study day. Whole blood gene expression analysis identified immunological changes associated with acute and chronic phases of infection, and further differences between initial challenge versus re-challenge. Conclusions The ability to challenge PTM with PkSPZ and achieve reliable blood stage infections indicate this model has significant potential for malaria vaccine studies. Blood stage P. knowlesi infection in PTM is characterized by low parasite burdens and a benign disease course, in contrast with the virulent P. knowlesi disease course commonly reported in rhesus macaques. These findings identify new opportunities for malaria vaccine research using this natural host-parasite combination. Graphical Abstract
Læs mere Tjek på PubMedMalaria Journal, 13.12.2023
Tilføjet 13.12.2023
Abstract Background Mass drug administration (MDA) and indoor residual spraying (IRS) are potent malaria burden reduction tools. The impact of combining MDA and IRS is not well documented. We evaluated the impact of MDA + IRS compared to IRS alone at a high transmission site in Eastern Uganda. Methods A quasi-experimental study was implemented in Toroma and Kapujan subcounties in north eastern Uganda. Both subcounties received four rounds of IRS using primiphos-methyl (Acttellic SC300) 6–8 months apart from December 2016 to December 2018. Eligible residents of Kapujan simultaneously received MDA using dihydroartemesinin-piperaquine (DHA-PQ). Health facility data was used to monitor malaria case incidence rate and test positivity rates. Results In the MDA + IRS arm, malaria incidence dropped by 83% (IRR: 0·17 (0.16–0.18); p
Læs mere Tjek på PubMedMalaria Journal, 13.12.2023
Tilføjet 13.12.2023
Abstract Background Light microscopy and rapid diagnostic tests (RDT) have long been the recommended diagnostic methods for malaria. However, in recent years, loop-mediated isothermal amplification (LAMP) techniques have been shown to offer superior performance, in particular concerning low-grade parasitaemia, by delivering higher sensitivity and specificity with low laboratory capacity requirements in little more than an hour. In this study, the diagnostic performance of two LAMP kits were assessed head-to-head, compared to highly sensitive quantitative real time PCR (qPCR), in a non-endemic setting. Methods In this retrospective validation study two LAMP kits; Alethia® Illumigene Malaria kit and HumaTurb Loopamp™ Malaria Pan Detection (PDT) kit, were evaluated head-to-head for detection of Plasmodium-DNA in 133 biobanked blood samples from suspected malaria cases at the Clinical Microbiology Laboratory of Region Skåne, Sweden to determine their diagnostic performance compared to qPCR. Results Of the 133 samples tested, qPCR detected Plasmodium DNA in 41 samples (defined as true positives), and the two LAMP methods detected 41 and 37 of those, respectively. The results from the HumaTurb Loopamp™ Malaria PDT kit were in complete congruence with the qPCR, with a sensitivity of 100% (95% CI 91.40–100%) and specificity of 100% (95% CI 96.07–100%). The Alethia® Illumigene Malaria kit had a sensitivity of 90.24% (95% CI 76.87–97.28) and a specificity of 95.65% (95% CI 89.24–98.80) as compared to qPCR. Conclusions This head-to-head comparison showed higher performance indicators of the HumaTurb Loopamp™ Malaria PDT kit compared to the Alethia® illumigene Malaria kit for detection of malaria.
Læs mere Tjek på PubMedAngella M. George, Rashid Ansumana, Dziedzom K. de Souza, Vettakkara Kandy Muhammed Niyas, Alimuddin Zumla, Moses J Bockarie
International Journal of Infectious Diseases, 13.12.2023
Tilføjet 13.12.2023
As the world experiences warmer weather, heat waves and flooding, the climate change is leading to the geographical expansion of mosquitos, which are known vectors of a range of infectious diseases like dengue, malaria, chikungunya, yellow fever, rift valley fever, West Nile fever, Japanese encephalitis and Zika which affect millions of people worldwide (1). Climate change now threatens the spread of vector-borne diseases to previously low-risk areas in Africa, Asia, Europe, and the Americas (2-7) According to the World Health Organization (WHO), an additional 250,000 deaths per year will occur in the next decades as a result of malnutrition, heat stress and vector-borne diseases (8).
Læs mere Tjek på PubMedDanny Xuan-Rong Koh, Mohamed Afiq Hidayat Zailani, Raja Zahratul Azma Raja Sabudin, Sanggari Muniandy, Nur Awatif Akmal Muhamad Hata, Siti Noor Baya Mohd Noor, Norhazilah Zakaria, Ainoon Othman, Endom Ismail
PLoS One Infectious Diseases, 12.12.2023
Tilføjet 12.12.2023
by Danny Xuan-Rong Koh, Mohamed Afiq Hidayat Zailani, Raja Zahratul Azma Raja Sabudin, Sanggari Muniandy, Nur Awatif Akmal Muhamad Hata, Siti Noor Baya Mohd Noor, Norhazilah Zakaria, Ainoon Othman, Endom Ismail Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked genetic disorder characterized by reduced G6PD enzyme levels in the blood. This condition is common in populations exposed to malaria; an acute febrile disease caused by Plasmodium parasites. G6PD-deficient individuals may suffer from acute hemolysis following the prescription of Primaquine, an antimalarial treatment. The population at risk for such a condition includes the Senoi group of Orang Asli, a remote indigenous community in Malaysia. This study aimed to elucidate the G6PD molecular heterogeneity in this subethnic group which is important for malaria elimination. A total of 662 blood samples (369 males and 293 females) from the Senoi subethnic group were screened for G6PD deficiency using a quantitative G6PD assay, OSMMR2000-D kit with Hb normalization. After excluding the family members, the overall prevalence of G6PD deficiency in the studied population was 15.2% (95% CI: 11–19%; 56 of 369), with males (30 of 172; 17.4%) outnumbering females (26 of 197; 13.2%). The adjusted male median (AMM), defined as 100% G6PD activity, was 11.8 IU/gHb. A total of 36 participants (9.6%; 26 male and 10 female) were deficient (G)(39.1%; n = 34), G6PD Viangchan (c.871G>A)(25.3%; n = 22), G6PD Union (c.1360C>T)(21.8%; n = 19), c.1311C>T(20.7%; n = 18), G6PD Kaiping (c.1388G>A)(8.0%; n = 7), and G6PD Coimbra (c.592C>T)(2.3%; n = 2). Our analysis revealed 27 hemizygote males, 18 heterozygote females, 7 homozygote females, and 2 compound heterozygote females. This study confirms the high prevalence of G6PD deficiency among the Senoi Malaysian Orang Asli, with a significant degree of molecular heterogeneity. More emphasis should be placed on screening for G6PD status and proper and safe use of Primaquine in the elimination of malaria among this indigenous population.
Læs mere Tjek på PubMedMalaria Journal, 12.12.2023
Tilføjet 12.12.2023
Abstract Background Plasmodium falciparum genetic diversity can add information on transmission intensity and can be used to track control and elimination interventions. Methods Dried blood spots (DBS) were collected from patients who were recruited for a P. falciparum malaria therapeutic efficacy trial in three malaria endemic sites in Ethiopia from October to December 2015, and November to December 2019. qPCR-confirmed infections were subject to amplicon sequencing of polymorphic markers ama1-D3, csp, cpp, cpmp, msp7. Genetic diversity, the proportion of multiclonal infections, multiplicity of infection, and population structure were analysed. Results Among 198 samples selected for sequencing, data was obtained for 181 samples. Mean MOI was 1.38 (95% CI 1.24–1.53) and 17% (31/181) of infections were polyclonal. Mean He across all markers was 0.730. Population structure was moderate; populations from Metema and Metehara 2015 were very similar to each other, but distinct from Wondogent 2015 and Metehara 2019. Conclusion The high level of parasite genetic diversity and moderate population structure in this study suggests frequent gene flow of parasites among sites. The results obtained can be used as a baseline for additional parasite genetic diversity and structure studies, aiding in the formulation of appropriate control strategies in Ethiopia.
Læs mere Tjek på PubMedMalaria Journal, 11.12.2023
Tilføjet 11.12.2023
Abstract Background Resistance against artemisinin-based combination therapy is one of the challenges to malaria control and elimination globally. Mutations in different genes (Pfdhfr, Pfdhps, Pfk-13 and Pfmdr1) confer resistance to artesunate and sulfadoxine–pyrimethamine (AS + SP) were analysed from Mandla district, Madhya Pradesh, to assess the effectiveness of the current treatment regimen against uncomplicated Plasmodium falciparum. Methods Dried blood spots were collected during the active fever survey and mass screening and treatment activities as part of the Malaria Elimination Demonstration Project (MEDP) from 2019 to 2020. Isolated DNA samples were used to amplify the Pfdhfr, Pfdhps, Pfk13 and Pfmdr1 genes using nested PCR and sequenced for mutation analysis using the Sanger sequencing method. Results A total of 393 samples were subjected to PCR amplification, sequencing and sequence analysis; 199, 215, 235, and 141 samples were successfully sequenced for Pfdhfr, Pfdhps, Pfk13, Pfmdr1, respectively. Analysis revealed that the 53.3% double mutation (C59R, S108N) in Pfdhfr, 89.3% single mutation (G437A) in Pfdhps, 13.5% single mutants (N86Y), and 51.1% synonymous mutations in Pfmdr1 in the study area. Five different non-synonymous and two synonymous point mutations found in Pfk13, which were not associated to artemisinin resistance. Conclusion The study has found that mutations linked to SP resistance are increasing in frequency, which may reduce the effectiveness of this drug as a future partner in artemisinin-based combinations. No evidence of mutations linked to artemisinin resistance in Pfk13 was found, suggesting that parasites are sensitive to artemisinin derivatives in the study area. These findings are a baseline for routine molecular surveillance to proactively identify the emergence and spread of artemisinin-resistant parasites.
Læs mere Tjek på PubMedInfectious Disease Modelling, 10.12.2023
Tilføjet 10.12.2023
Publication date: Available online 9 December 2023 Source: Infectious Disease Modelling Author(s): Francis Oketch Ochieng
Læs mere Tjek på PubMedMalaria Journal, 10.12.2023
Tilføjet 10.12.2023
Abstract Background Malaria is a major global health challenge, and for the elimination and eradication of this disease, transmission-blocking vaccines (TBVs) are a priority. Plasmodium falciparum Generative Cell Specific 1 (PfGCS1), a promising TBV candidate, is essential for gamete fertilization. The HAP2-GCS1 domain of this antigen as well as its cd loop could induce antibodies that partially inhibit transmission of P. falciparum. Methods In the current study, a new synthetic fusion antigen containing cd loop and HAP2-GCS1 domain (cd-HAP) of PfGCS1 was evaluated as a transmission blocking vaccine candidate. Initially, the profile of naturally acquired IgG antibodies to the cd-HAP antigen was analysed in Iranian individuals infected with P. falciparum, to confirm that this new fusion protein has the appropriate structure containing common epitopes with the native form of PfGCS1. Then, the immunogenicity of cd-HAP was evaluated in BALB/c mice, using different adjuvant systems such as CpG, MPL, QS-21, and a combination of them (CMQ). Furthermore, the blocking efficacy of polyclonal antibodies induced against these formulations was also assessed by oocyst intensity and infection prevalence in the Standard Membrane Feeding Assay (SMFA). Results The naturally acquired antibodies (dominantly IgG1 and IgG3 subclasses) induced in P. falciparum-infected individuals could recognize the cd-HAP antigen which implies that the new fusion protein has a proper conformation that mimics the native structure of PfGCS1. Concerning the immunogenicity of cd-HAP antigen, the highest IgG levels and titers, by a Th1-type immune profile, and elevated antibody avidity were induced in mice immunized with the cd-HAP antigen formulated with a combination of adjuvants (P
Læs mere Tjek på PubMedAdetunji, 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.
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