Malaria-endemic Regions Research Articles

The Role of Nutritional Interventions in Integrated Care for Malaria and Anemia Management

Malaria and anemia are interrelated public health challenges that disproportionately affect vulnerable populations in sub-Saharan Africa, particularly children and pregnant women. The dual burden of these conditions requires integrated care strategies to effectively manage and reduce their prevalence. Nutritional interventions, such as dietary improvements and iron supplementation, are essential in this context, as they address iron deficiencies, bolster immune function, and mitigate the severity of both conditions. This review explores the role of nutritional interventions in managing malaria and anemia, evaluating the effectiveness of dietary programs and iron supplementation within African public health frameworks. It examines the complexities of integrating nutritional strategies with malaria control measures and highlights the challenges, including resource limitations, cultural barriers, and fragmented policies. The review underscores the importance of coordinated policy frameworks, community engagement, and increased resource allocation to optimize the impact of integrated care strategies. Recommendations for strengthening these approaches are provided to enhance health outcomes and reduce the disease burden in malaria-endemic regions. Keywords: Malaria, Anemia, Nutritional Interventions, Iron Supplementation, Public Health Strategies.

Assessment of different genotyping markers and algorithms for distinguishing Plasmodium falciparum recrudescence from reinfection in Uganda

Antimalarial therapeutic efficacy studies are vital for monitoring drug efficacy in malaria-endemic regions. The WHO recommends genotyping polymorphic markers including msp-1, msp-2, and glurp for distinguishing recrudescences from reinfections. Recently, WHO proposed replacing glurp with microsatellites (Poly-α, PfPK2, TA1). However, suitable combinations with msp-1 and msp-2, as well as the performance of different algorithms for classifying recrudescence, have not been systematically assessed. This study investigated various microsatellites alongside msp-1 and msp-2 for molecular correction and compared different genotyping algorithms across three sites in Uganda. Microsatellites 313, Poly-α, and 383 exhibited the highest diversity, while PfPK2 and Poly-α revealed elevated multiplicity of infection (MOI) across all sites. The 3/3 match-counting algorithm classified significantly fewer recrudescences than both the ≥ 2/3 and Bayesian algorithms at probability cutoffs of ≥ 0.7 and ≥ 0.8 (P < 0.05). The msp-1/msp-2/2490 combination identified more recrudescences using the ≥ 2/3 and 3/3 algorithms in the artemether-lumefantrine (AL) treatment arm, while msp-1/msp-2/glurp combination classified more cases of recrudescence using the ≥ 2/3 in the dihydroartemisinin-piperaquine (DP) arm. Microsatellites PfPK2 and Poly-α, potentially sensitive to detecting minority clones, are promising replacements for glurp. Discrepancies in recrudescence classification between match-counting and Bayesian algorithms highlight the need for standardized PCR correction practices.

Molecular detection of Wolbachia sp. and Cytoplasmic incompatibility factors (CifA/B) in wild caught mosquitoes in Côte d'Ivoire.

Wolbachia is an endosymbiont bacterium known to stimulate host immunity against arboviruses and protozoa. Côte d'Ivoire is in a malaria-endemic region, and has experienced several dengue epidemics in recent decades as well. In order to help reduce the transmission of pathogens by mosquito vectors, we studied the prevalence of Wolbachia and the distribution of Cytoplasmic incompatibility factors (Cif) genes in different mosquito species caught in the wild in Cote d'Ivoire. Mosquitoes of the genera Anopheles, Aedes, Culex, Eretmapodites and Mansonia were captured in five cities. Mosquitoes were collected at larval stage in breeding sites and adults were captured using BG sentinel traps. The mosquitoes were identified morphologically and Wolbachia and Cif were screened using qPCR targeting the 16s rRNA gene and the CifA, B genes. A total of 518 mosquito samples belonging to 15 species and 4 genera were examined. 60% of the species were infected with Wolbachia. The three medically important mosquito species Aedes aegypti, Anopheles gambiae s.l. and Culex quinquefasciatus had a prevalence of 12.84%, 13.46% and 72.64% respectively. The Wolbachia strains infecting the different mosquito species of the genus Culex encoded 98.46% for the CifA gene and 77.69% for the CifB gene. The presence of Wolbachia and CifA, B genes in mosquitoes of different species in Côte d'Ivoire offer a promising opportunity to reduce the competence of mosquito vectors. Characterization of Wolbachia strains and cytoplasmic incompatibility factors will provide a better understanding of these endosymbionts, enabling the development of vector control strategies.

Role of medicinal plant in treatment of malaria

Medicinal plants have played a crucial role in the treatment of malaria, providing a foundation for some of the most effective antimalarial drugs, such as quinine from Cinchona and artemisinin from Artemisia annua. These plants are rich in bioactive compounds with potent antimalarial properties, making them valuable in combating malaria, particularly in regions with limited access to synthetic drugs. However, their use is not without challenges, including variability in efficacy, safety concerns, and the emergence of drug-resistant Plasmodium strains. Despite these limitations, the integration of medicinal plants into modern therapies offers significant potential for innovation, such as developing combination treatments, biotechnological advancements for consistent production, and personalized medicine approaches. Additionally, promoting the cultivation of medicinal plants can support sustainable healthcare solutions in malaria-endemic regions. As research advances, medicinal plants will continue to play a vital role in addressing drug resistance and providing accessible, culturally relevant malaria treatments.

Investigation of malaria vectors Anopheles in non-endemic areas of Thailand: in proximity to workplaces housing foreign migrant workers

BackgroundForeign migrant workers from malaria-endemic regions play a critical factor in the transmission of malaria to non-endemic areas, mainly due to their mobility while seeking employment opportunities. This risk is particularly heightened in areas where malaria vectors are present.MethodsThis study aimed to investigate the malaria vectors in two sub-districts in Khon Kaen Province, known for their factory areas and the significant presence of Myanmar migrant worker communities. The collection was carried out from June 2020 to May 2021. The black light traps (BLT) operated continuously from 6:00 pm to 6:00 am (12 h) and Kelambu trap (KT) were set up from 6:00 pm to 9:00 pm, with both traps set up once a month. A total of 679 female Anopheles mosquitoes were collected near the workplaces and dormitories of these workers. Subsequently, the collected female mosquitoes underwent morphological identification using Standard Thailand keys and polymerase chain reaction analysis with rDNA ITS2 primers.ResultsMorphological identification revealed that 201 (29.6%) belonged to the Barbirostris complex. The remaining Anopheles mosquitoes are in the subgroup Cellia, comprised 437 (64.4%) Anopheles vagus, 39 (5.7%) Anopheles subpictus, and 2 (0.3%) Anopheles annularis. To distinguish the Barbirostris complex, multiplex PCR based on ITS-2 sequences was conducted. Out of the 201 specimens examined, 153 (76.1%) as Anopheles campestris, 36 (17.9%) as Anopheles wejchoochotei, and 12 (6%) as Anopheles dissidens. Additionally, the subgroup Anopheles Cellia was confirmed using specific primers based on ITS-2 sequences.ConclusionsFrom the obtained results, An. campestris, An. wejchoochotei, An. vagus and An. annularis are reported as the malaria vectors in Thailand. The findings emphasized the important of addressing the presence of Anopheles malaria vectors, especially in the substantial migrant worker population originating from endemic areas. This situation raises concerns regarding the potential transmission of malaria infections to regions not traditionally affected by the disease. Epidemiological studies on malaria vectors should not solely concentrate on endemic regions but also extend to non-endemic areas because of the mobility of migrant workers throughout the country. This broader approach is crucial for implementing an effective malaria surveillance strategy.Graphical

Multi-System Dysregulation in Placental Malaria Contributes to Adverse Perinatal Outcomes in Mice.

Sequestration of Plasmodium parasites in the placental vasculature causes increased morbidity and mortality in pregnant compared to non-pregnant patients in malaria-endemic regions. In this study, outbred pregnant CD1 mice with semi allogeneic fetuses were infected with transgenic Plasmodium berghei or mock-inoculated by mosquito bite at either embryonic day (E) 6 (first trimester-equivalent) or 10 (second trimester-equivalent) and compared with non-pregnant females. P. berghei-infected mosquitoes had greater biting avidity for E10 dams than uninfected mosquitoes, which was not apparent for E6 dams nor non-pregnant females. Infected E10 dams had greater numbers of parasites than E6 dams in the uterus and spleen, but not in the blood or liver. While parasites were found in placentas, no parasites were present in fetuses. Maternal infection at E6 caused greater maternal morbidity, with greater rates of fetal reabsorption and stillbirths than at E10. Infection at E10 caused adverse offspring outcomes, including growth restriction. To identify possible mechanisms of adverse offspring outcomes, E10 dams were euthanized during peak parasitemia (8 days post infection), and outcomes were compared with mock-infected dams. P. berghei caused significant systemic maternal immune activation with elevated circulating lymphocytes, eosinophils, and neutrophils and splenic cytokine concentrations. P. berghei infection at E10 increased corticosterone and decreased progesterone concentrations, which could contribute to adverse perinatal outcomes through immunomodulation. There were limited changes in the maternal fecal microbiome after P. berghei infection. Mosquito bite infection of outbred dams with P. berghei causes placental malaria and provides a novel, tractable model to investigate therapeutic treatments.

Targeting Plasmodium falciparum chondroitin sulfate a ligand: A highly conserved malaria antigen with potential for pregnancy-associated malaria vaccine development

Background Pregnant women in malaria-endemic regions exhibit heightened susceptibility to Plasmodium falciparum infection due to accumulation of infected red blood cells (iRBCs) in the placenta. This is aided by the variant antigen 2 chondroitin sulfate A (VAR2CSA) protein which remains a target for pregnancy-associated malaria (PAM) vaccine studies. However, polymorphism in this antigen presents a significant challenge in developing broadly efficacious vaccines. This study explored PfCSA-L, a protein co-expressed and co-localized with VAR2CSA, as a potential alternative vaccine target due to its hypothesized role in PAM pathogenesis. Methods Sera and dried blood spots were collected from pregnant women attending antenatal care clinic at Webuye County Hospital, Western Kenya. P. falciparum infection status was confirmed by PCR. Recombinant PfCSA-L, expressed using a eukaryotic wheat germ cell-free system (WGCFS), was used to assess IgG antibody responses via ELISA. Results We observed a statistically significant increase in IgG levels as gestation advanced, suggesting potential exposure-driven antibody maturation against PfCSA-L. Primigravida women exhibited a trend toward higher anti-PfCSA-L antibody levels compared to multigravida during the second visit, possibly reflecting a more vigorous immune response during the first pregnancy. Genetic analysis of field parasite isolates revealed a high conservation of PfCSA-L at both DNA and protein levels. B-cell epitope prediction identified potential targets on the PfCSA-L surface within the conserved region. Conclusion These findings, coupled with the observed IgG response, further positions PfCSA-L as a promising vaccine candidate for PAM. However, further investigations are warranted to elucidate the functional role of anti-PfCSA-L antibodies and definitively validate PfCSA-L and/or the identified epitopes as potential PAM vaccine targets.

Evidence of SARS-CoV-2 Spread in Rural Tanzania During the First 6 Months of the Global COVID-19 Pandemic.

In the first 6 months of the coronavirus disease 2019 pandemic, limited testing clouded understanding of the extent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in Africa. In particular, Tanzania halted all testing and reporting of SARS-CoV-2 cases after May 2020, not resuming until June 2021. In July-August 2020, we performed a seroprevalence survey in rural Bagamoyo district, 40 km outside Dar es Salaam. Among 347 asymptomatic children and adults, 64/347 (18.0%) demonstrated seroreactivity to SARS-CoV-2 spike receptor binding domain by ELISA. Given significant antibody cross-reactivity in malaria-endemic regions, seropositivity was additionally confirmed via a multitarget Luminex immunoassay. Thirty-seven, or 58% of initially seroreactive persons, were Luminex positive, leading to an estimated SARS-CoV-2 seroprevalence of 10.7% (37/347, 95% CI 7.6-14.4%). Working in health care appeared to be associated with seropositivity. Reporting of viral symptoms or health care-seeking behavior in the previous 3 months was not more frequent in seropositive individuals.

Assessing the Feasibility of Using a Multiplex Serological Assay to Conduct Serosurveillance for Malaria Exposure in Deployed Military Personnel.

Reproducibly assessing malaria exposure is critical for force health protection for military service members deployed to malaria-endemic regions as well as for civilians making public health decisions and evaluating malaria eradication efforts. However, malaria disease surveillance is challenged by under-reporting, natural immunity, and chemoprophylaxis, which can mask malaria exposure and lead to an underestimation of malaria prevalence. In this study, we determined the feasibility of using a serosurveillance-based approach to measure Anopheles vector exposure, Plasmodium sporozoite exposure, and blood-stage parasitemia using a multiplex serological panel. We tested post-deployment samples obtained from U.S. service members returning from regions with malaria risk to assess the potential of this serosurveillance panel. The results identified that some service members had anti-CSP antibody levels comparable to those found in endemic populations, suggesting exposure to sporozoites while those individuals were on chemoprophylaxis. We also observed isolated cases of anti-MSP1 levels that were as high as those observed in endemic populations and in CHMI studies, suggesting possible cases of clinical or subclinical parasitemia. The study demonstrated the feasibility of implementing a multiplex serology approach for conducting serosurveillance for Anopheles vector exposure and Plasmodium parasite exposure in samples collected following military deployments and its potential to support public health policies.

Relative efficacy of anti-Plasmodium vivax malaria combination drugs in preventing transmission to two major Anopheles mosquitos in the first few days of treatment

The World Health Organization recommends three drug anti-malarial combinations: cloroquine+primaquine, artesiminin+primaquine, and cloroquine+tafenoquine. These combinations aim to eradicate Plasmodium by disrupting its life cycle within the human body. We evaluated the effect of these medications on the vectorial competence of two main vectors in the New World. We recruited patients diagnosed with malaria vivax from a primary care in Manaus, Amazonas. To determine how different treatments affected vectors, we collected blood samples prior to treatment at the hospital and at six intervals over the next 68 hours at the patient's homes. These samples were used to infect Anopheles darlingi and Anopheles aquasalis. To assess the potential for Plasmodium transmission by bite to a new human host, we analyzed the infection intensity, infection rate, and presence of parasites in the salivary gland of the mosquitoes. The results show the infection of the mosquitoes fed with the patient's blood during the first days of treatment with all three drug combinations. However, the cloroquine+tafenoquine combination was the least effective while artesiminin+primaquine was the most effective. In the first few days of treatment, two main vectors continue to spread malaria vivax from patients, potentially contributing to the ongoing transmission in malaria-endemic regions.

Evaluation of an Artificial Intelligence-Based Tool and a Universal Low-Cost Robotized Microscope for the Automated Diagnosis of Malaria.

The gold standard diagnosis for malaria is the microscopic visualization of blood smears to identify Plasmodium parasites, although it is an expert-dependent technique and could trigger diagnostic errors. Artificial intelligence (AI) tools based on digital image analysis were postulated as a suitable supportive alternative for automated malaria diagnosis. A diagnostic evaluation of the iMAGING AI-based system was conducted in the reference laboratory of the International Health Unit Drassanes-Vall d'Hebron in Barcelona, Spain. iMAGING is an automated device for the diagnosis of malaria by using artificial intelligence image analysis tools and a robotized microscope. A total of 54 Giemsa-stained thick blood smear samples from travelers and migrants coming from endemic areas were employed and analyzed to determine the presence/absence of Plasmodium parasites. AI diagnostic results were compared with expert light microscopy gold standard method results. The AI system shows 81.25% sensitivity and 92.11% specificity when compared with the conventional light microscopy gold standard method. Overall, 48/54 (88.89%) samples were correctly identified [13/16 (81.25%) as positives and 35/38 (92.11%) as negatives]. The mean time of the AI system to determine a positive malaria diagnosis was 3 min and 48 s, with an average of 7.38 FoV analyzed per sample. Statistical analyses showed the Kappa Index = 0.721, demonstrating a satisfactory correlation between the gold standard diagnostic method and iMAGING results. The AI system demonstrated reliable results for malaria diagnosis in a reference laboratory in Barcelona. Validation in malaria-endemic regions will be the next step to evaluate its potential in resource-poor settings.

A biobank resource for placental malaria and placental health research

Background Malaria during pregnancy is a serious threat to maternal and child health in malaria-endemic regions. Malaria during pregnancy often leads to placental malaria, which has severely detrimental effects on fetal outcomes, including fetal growth restriction, preterm delivery, and stillbirth. However, the mechanisms by which placental malaria causes adverse outcomes remain poorly understood. Crucially, there are no tools for detecting and/or intervening in placental malaria during pregnancy. This is mainly because the placenta is inaccessible to research during pregnancy. Nonetheless, its accessibility after delivery offers unique opportunities for studying placental diseases. To support such research, collecting and biobanking naturally-infected placental samples in the geographical context in which diseases of interest occur is crucial. Methods Here, we describe the establishment of a biobank of samples obtained from a malaria-endemic region of Kenya, which aims to enhance research capacity in this important but under-studied health challenge. Histology, PCR, and isothermal identical multirepeat sequence PCR were used to determine the placental malaria status of biobank samples. Results Our biobank characterization indicates that placental malaria affects most pregnancies in the malaria-endemic region, despite mothers being asymptomatic during pregnancy and having received anti-malaria chemoprophylaxis. Of the techniques used to detect placental malaria, isothermal identical multirepeat sequence PCR detected the highest number of placental malaria-positive samples (54.2%), compared with placental histology (37.3%), and placenta tissue PCR (17%). However, results from the various techniques did not overlap fully. Conclusion Our observations highlight the need to rigorously characterize placental samples from malaria-endemic regions, including by using multiple complementary techniques, even in cases of undetectable malaria during pregnancy. It may also be beneficial to obtain samples from non-malaria-endemic regions for use as placental malaria-naïve controls.

Assessing the Impact of Intermittent Preventive Treatment in Reducing Malaria Incidence among Pregnant Women in High-Risk Areas

Malaria poses significant health risks for pregnant women, especially in high-transmission areas such as sub-Saharan Africa. Physiological and immunological changes during pregnancy increase vulnerability to malaria-related complications, including maternal anemia, low birth weight, and preterm delivery, which can severely impact maternal and neonatal health. To combat these risks, the World Health Organization (WHO) recommended Intermittent Preventive Treatment in Pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) as a proactive measure to reduce malaria incidence in this population. IPTp-SP, administered at regular intervals starting from the second trimester, has shown promising outcomes, such as reduced malaria prevalence, improved maternal hemoglobin levels, and lower incidence of placental malaria. This narrative review synthesized current literature on IPTp’s effectiveness, challenges, and future directions, analyzing studies across multiple high-risk regions to highlight both successes and barriers in IPTp implementation. Key challenges identified include rising SP resistance, limited healthcare infrastructure, and socio-cultural obstacles impacting adherence. To address these, alternative strategies such as introducing alternative antimalarial drugs like dihydroartemisinin-piperaquine (DP), expanding antenatal care (ANC) services, and utilizing community health workers (CHWs) to improve IPTp delivery are examined. Emerging mobile health (mHealth) tools are also explored as potential solutions for enhancing adherence. Recommendations for policy included investment in ANC infrastructure, community-based outreach, and increased support for research on SP alternatives. The findings underscored IPTp’s essential role in protecting maternal and child health, while highlighting areas for innovation and policy reform to optimize its impact in malaria-endemic regions. Keywords: Intermittent Preventive Treatment (IPTp), Malaria, Pregnant Women, Sulfadoxine-Pyrimethamine (SP), Public Health.

Plasmodium falciparum African PfCRT Mutant Isoforms Conducive to Piperaquine Resistance are Infrequent and Impart a Major Fitness Cost.

Piperaquine, used in combination with dihydroartemisinin, has been identified as a promising partner drug for uncomplicated treatment and chemoprevention of Plasmodium falciparum malaria in Africa. In light of the earlier spread of piperaquine resistance in Southeast Asia, mediated primarily by mutations in the drug efflux transporter PfCRT, we have explored whether PfCRT mutations would represent a probable path to piperaquine resistance becoming established in Africa. We edited PfCRT mutations known to mediate piperaquine resistance in Southeast Asia into P. falciparum asexual blood stage parasites expressing three prevalent African mutant PfCRT haplotypes. Gene-edited clones were profiled in antimalarial concentration-response and competitive fitness assays. pfcrt-edited parasites expressing the contemporary Southeast Asian T93S or I218F mutations added to the GB4 and Cam783 haplotypes common in Africa did not mediate piperaquine resistance, with partial survival only at low drug concentrations. In contrast, parasites expressing these mutations on the rare PfCRT FCB haplotype, observed mostly in North-East Africa, acquired a moderate level of piperaquine resistance. Dd2GB4, Dd2Cam783, and Dd2FCB lines edited to express the T93S or I218F mutations showed increased susceptibility to chloroquine. Piperaquine-resistant African PfCRT isoforms conferred a substantial fitness cost, manifesting as reduced asexual blood stage parasite growth rates. These findings suggest that piperaquine-resistant PfCRT mutations that emerged in Southeast Asia mediate resistance only in a limited subset of African PfCRT haplotypes, with fitness costs that we suspect would likely preclude dissemination in high-transmission malaria-endemic African regions.

Preliminary Evidence of Human Plasmodium in Domestic Animals from a Malaria-Endemic Region in Indonesia

Background In Indonesia, malaria incidence is at a high rate despite maximum preventive efforts. Therefore, this study aims to determine the possibility of a Plasmodium reservoir among domestic animals in malaria-endemic areas. Methods Animal blood was collected using EDTA tubes, then smeared and stained with Giemsa for Plasmodium microscopic identification. About 10 μl of blood was dropped on to a filter paper to capture Plasmodium DNA. Nested PCR was used for parasite molecular detection, while Plasmodium species were identified using the sequenced DNA. Results A total of 208 and 62 animal blood samples were collected from Gaura village, West Sumba and Fakfak village, West Papua, Indonesia respectively. In total, 32 samples from Gaura contained P. falciparum or P. vivax, while the Plasmodium percentage in buffalo, horse, goat, and dogs were 20.7%, 14.3%, 5.8%, 16.7%, respectively. P. knowlesi was not found in any of the samples, and no other species were detected in 18 pig blood samples. Conclusion The human Plasmodium DNA in domestic animals within malaria-endemic regions suggests a potential link to the persistence and high prevalence of malaria in these areas. While the findings suggest a potential role of domestic animals in malaria transmission, they remain preliminary and do not definitively establish domestic animals as reservoirs. Further research is necessary to confirm these findings and to better understand the contribution of domestic animals to the transmission dynamics of malaria.

Severe falciparum malaria in young children is associated with an increased risk of post-discharge hospitalization: a prospective cohort study

BackgroundFew studies have described post-discharge morbidity of children with specific manifestations of severe malaria (SM) beyond severe malarial anaemia or cerebral malaria.MethodsChildren 6 months to 4 years of age admitted at Jinja and Mulago hospitals in Uganda, with one or more of the five most common forms of SM, cerebral malaria (n = 53), respiratory distress syndrome (n = 108), malaria with complicated seizures (n = 160), severe malarial anaemia (n = 155) or prostration (n = 75), were followed for 12 months after discharge, alongside asymptomatic community children (CC) (n = 120) of similar ages recruited from the households or neighbourhoods of the children with SM. Incidence and risk of hospitalizations, death or outpatient clinic visits were compared between children with SM and CC.Results312/551 (56.6%) of children with SM had one or more post-discharge hospitalization over 12 months, compared to 37/120 (30.8%) of CC. Frequency of hospitalization was similar across all forms of SM. Compared to CC, children with SM had a significantly higher risk of all-cause hospitalization (adjusted hazard ratio (aHR) 1.91, 95% confidence interval (CI) 1.39–2.63, p < 0.001) and hospitalization for severe malaria (aHR 1.94, CI 1.36–2.78, p < 0.001), but a similar risk of outpatient clinic visits for malaria (aHR 1.24, 95% CI 0.89–1.73, p = 0.20). 82% of hospitalizations in children with SM (575/700) and CC (50/61) were due to malaria.ConclusionsIn this malaria endemic region, children with the five most common forms of SM had higher rates of post-discharge hospitalization than asymptomatic community children, and > 80% of hospitalizations were due to severe malaria. Studies of post-discharge malaria chemoprevention are urgently needed for children with SM, to determine if this treatment can reduce post-discharge morbidity.

Environmental Impact Assessment for Sustainable Development in Malaria-Endemic Regions: Addressing the Threat of Drug-Resistant Plasmodium falciparum in Africa

Environmental Impact Assessment for Sustainable Development in Malaria-Endemic Regions: Addressing the Threat of Drug-Resistant Plasmodium falciparum in Africa

Heterogeneous mosquito exposure increases Plasmodium vivax and Plasmodium falciparum co-infections: a modelling study.

In malaria-endemic regions, Plasmodium vivax and Plasmodium falciparum coexist and may interact. For instance, fevers induced by P. falciparum might activate dormant P. vivax parasites and concurrent radical cure of both species has been proposed to prevent relapses. Heterogeneous mosquito exposure may contribute to the dependence of both parasites. We conducted a literature review on their respective prevalence and that of co-infections. The data revealed a positive correlation between P. vivax and P. falciparum prevalence, and co-infection prevalences exceeding expectations assuming infections occur independently. We used the review data to fit a compartmental model of co-infections that features heterogenous mosquito exposure. The fit suggests that heterogeneous exposure sufficiently explains the observed departure from independence. Finally, we performed simulations under the model assessing the impact on P. vivax prevalence of the activation-by-fever hypothesis and the radical cure proposition. We demonstrated a moderate impact of allowing P. falciparum fevers to reactivate P. vivax and a substantial impact of treating P. falciparum cases with radical cure. Our model highlights dependence between P. falciparum and P. vivax and emphasizes the influence of heterogeneous mosquito exposure. This simple framework can inform the design of more complex models assessing integrated malaria control strategies in coendemic regions.

Evaluation of three rapigen biocredit point-of-care tests for malaria case management in Lagos, Nigeria

Introduction: Histidine-rich protein 2 (HRP2) antigen kits are widely used for malaria diagnosis in tropical regions due to their heat stability. The Plasmodium Lactate Dehydrogenase (pLDH) used in BIOCREDIT® malaria test kit is claimed to be heat-stable. This study aimed to evaluate the heat stability and field performance of three BIOCREDIT® kits. Methodology: A cross-sectional community survey of malaria infection was carried out in Agbowa and Ikosi communities in Lagos State. Finger-prick blood was used to assess the performance of three BIOCREDIT® kits: Kit 1 (PfpLDH), Kit 2 (PfLDH/HRP2), and Kit 3 (PfLDH/PvLDH). Malaria microscopy and a reference mRDT (SD BIOLINE® PfHRP2) were used as comparators. Heat stability testing was performed using Plasmodium falciparum panels after exposure to 35oC and 45oC for 60 days. A total of 834 participants were recruited. Results: The sensitivity of BIOCREDIT® kits were: Kit 1 (PfLDH) 88.4%; Kit 2 PfHRP2 92% and PfLDH 86.6%; Kit 3 (PfLDH) 88.4%. The specificity of kits was: Kit 1 (Pf LDH) 91.7%; Kit 2 (PfHRP2) 82.3%) and (PfLDH) 92.1%; Kit 3 (PfLDH) 91.6%. The sensitivity and specificity of the reference kit were 92.9% and 85.9%. The three BIOCREDIT® Kits were stable. No potential case of pfhrp2 gene deletion was observed. Conclusions: The sensitivities of the three BIOCREDIT® malaria test kits were similar to the reference kit (SD BIOLINE mRDT). However, the specificities of PfLDH kits were significantly higher than the specificities of PfHRP2 kits. The BIOCREDIT® kits are suitable to be deployed in malaria-endemic tropical regions.

Examination of the Toxicity Pattern and Influence of Azadirachta indica on Testicular Function and Expression of Proliferating Cell Nuclear Antigen in Plasmodium berghei-Infected Mice

Background: Malaria, a parasitic disease caused by a single-celled parasite called Plasmodium, poses a significant global health burden, especially in tropical regions such as Africa. The impact of malaria on human health is well-documented; however, its effects on the male reproductive system and the impact of herbal extracts remain underexplored. Objectives: This study aims to investigate Azadirachta indica's toxicity and its antimalarial potency's influence on testicular function and expression of proliferating cells nuclear antigen (PCNA). Methods: The antimalarial activity of Azadirachta indica was determined using standard procedures. Thirty male mice were used and grouped into six. Group 1 (normal control), group 2 (P. berghei infected only - negative control), group 3 (Plasmodium berghei infected + lonart - standard drug), group 4 (P. berghei infected + 100 mg/kg BWT crude ethanol extract), group 5 (P. berghei infected + 200 mg/kg BWT crude ethanol extract), group 6 (P. berghei infected + 400 mg/kg BWT crude ethanol extract). Administration of A. indica leaf extract to infected mice for four consecutive days demonstrated promising results. Results: The extract significantly suppressed parasite multiplication, ameliorated testicular damage, and improved sperm quality. The non-toxic extract also reduced oxidative stress in the testes, suggesting its potential effectiveness as phytotherapy against malaria-induced male reproductive impairments. Conclusions: The beneficial effects of A. indica emphasize its potential as a natural remedy for malaria-induced reproductive complications, offering a new avenue for therapeutic intervention in malaria-endemic regions. This study contributes to our knowledge of the intricate relationship between malaria and male reproductive health and provides valuable insights for future research and clinical applications.