Malaria Infection Research Articles

Antibodies to PfEMP1 and variant surface antigens: Protection after controlled human malaria infection in semi-immune Kenyan adults

Acquisition of antibodies to Plasmodium falciparum variant surface antigens (VSA) expressed on infected red blood cells (iRBCs) is associated with naturally acquired immunity to malaria. We have previously shown that antibodies to VSA on iRBCs are associated with protection against parasite growth in the context of controlled human malaria infection (CHMI). This study explored whether antibodies to recombinant antigens derived from PfEMP1 domains were independently associated with protection during CHMI in semi-immune Kenyan adults. We used a multiplex bead assay to measure levels of IgG antibody against a panel of 27 recombinant PfEMP1 antigens derived from the PfEMP1 repertoire of the 3D7 parasite clone. We measured IgG levels in plasma samples collected from the CHMI participants before inoculation with Sanaria® PfSPZ Challenge, on the day of diagnosis, and 35 days post-inoculation. Univariable and multivariable Cox regression analysis was used to evaluate the relationship between the levels of antibodies to the antigens and CHMI outcome. We also adjusted for previous data including antibodies to VSA on iRBCs, and we assessed the kinetics of antibody acquisition to the different PfEMP1 recombinant antigens over time. All study participants had detectable antibodies to multiple PfEMP1 proteins before inoculation. All PfEMP1 antigens were associated with protection against parasite growth to the threshold criteria for treatment in CHMI, albeit with substantial collinearity. However, individual PfEMP1 antigens were not independently associated with protection following adjustment for breadth of reactivity to VSA on iRBCs and schizont extract. In addition, antibodies to PfEMP1 antigens derived from group B PfEMP1 were induced and sustained in the participants who could not control parasite growth. This study shows that the breadth of antibody response to VSA on iRBCs, and not to specific PfEMP1 antigens, is predictive of protection against malaria in CHMI.

Advancing spatial repellents for malaria control: effectiveness and cost-effectiveness of a spatial repellent under operational use in Northern Uganda—study protocol for a cluster randomized controlled trial

BackgroundSpatial repellents (SRs) have been widely used for the prevention of mosquito bites, and preliminary findings suggest efficacy against both malaria (1) and Aedes-borne viruses (2) but their effectiveness in reducing mosquito-borne diseases under operational use has never been evaluated. SRs have the potential of being critical tools in the prevention of mosquito-borne diseases in contexts where typical vector control strategies, such as insecticide-treated nets (ITNs) and indoor residual spraying, are inaccessible or underutilized such as among displaced persons or in emergency relief settings.MethodsChildren will be enrolled in 3 separate cohorts to establish the effectiveness of SRs in reducing malaria infection in different distribution channels. One cohort will estimate the direct effect of the SR distributed through a reference channel (study personnel distribution). The two remaining cohorts will estimate the protection of the SR distributed through a voucher channel and the Village Health Team channel. Cohorts will be followed twice a month (approximately every 15 days): during the first scheduled household visit in the month, a blood sample will be taken for malaria rapid diagnostic test (Monthly Visit #1); and, during the second scheduled household visit, a blood sample will only be taken if the participant has a recent history of fever (Monthly Visit #2). The incidence of malaria in each cohort will be estimated and compared to the reference cohort to determine the benefit of using a SR in an area with high, year-round transmission of malaria.DiscussionThis study will address the knowledge gap of whether or not SRs are effective in reducing human malaria disease in humanitarian assistance and emergency response settings in sub-Saharan Africa where underlying transmission rates are historically high and ITNs may or may not be widely deployed. This research will inform policy makers on whether to recommend SRs as a means to further reduce malaria transmission for such operational programs.Trial registrationClinicalTrials.gov NCT06122142. Registered on November 8, 2023.

Host-pathogen interactions in the Plasmodium-infected mouse liver at spatial and single-cell resolution

Upon infecting its vertebrate host, the malaria parasite initially invades the liver where it undergoes massive replication, whilst remaining clinically silent. The coordination of host responses across the complex liver tissue during malaria infection remains unexplored. Here, we perform spatial transcriptomics in combination with single-nuclei RNA sequencing over multiple time points to delineate host-pathogen interactions across Plasmodium berghei-infected liver tissues. Our data reveals significant changes in spatial gene expression in the malaria-infected tissues. These include changes related to lipid metabolism in the proximity to sites of Plasmodium infection, distinct inflammation programs between lobular zones, and regions with enrichment of different inflammatory cells, which we term ‘inflammatory hotspots’. We also observe significant upregulation of genes involved in inflammation in the control liver tissues of mice injected with mosquito salivary gland components. However, this response is considerably delayed compared to that observed in P. berghei-infected mice. Our study establishes a benchmark for investigating transcriptome changes during host-parasite interactions in tissues, it provides informative insights regarding in vivo study design linked to infection and offers a useful tool for the discovery and validation of de novo intervention strategies aimed at malaria liver stage infection.

High prevalence of asymptomatic and subpatent Plasmodium falciparum infections but no histidine-rich protein 2 gene deletion in Bouaké, Côte d’Ivoire

This study aimed to estimate the prevalence of asymptomatic and subpatent P. falciparum infections in the city of Bouaké, Central Côte d’Ivoire, to compare the performance of three tests, and to investigate potential P. falciparum histidine-rich protein 2 (pfhrp2) gene deletions. A cross-sectional survey was conducted in nine neighborhoods in Bouaké in 2016. Matched light microscopy (LM), rapid diagnostic test (RDT), and quantitative PCR (qPCR) data were used to determine the prevalence of P. falciparum infection and compare the performance of the three diagnostic tests. Pfhrp2/3 deletions were genotyped by digital PCR. Among 2313 individuals, 97.2% were asymptomatic and 2.8% were symptomatic. P. falciparum prevalence among symptomatic individuals was 25.8%, 30.3%, and 40.9% by LM, RDT, and varATS qPCR, respectively, and among asymptomatic individuals, it was 10.3%, 12.5%, and 34.9%. Asymptomatic infections comprised 96.4% of all malaria infections, with 58.2% detectable only by varATS qPCR. Although the prevalence of asymptomatic P. falciparum infections was higher in school-age children (5–14 years: 42.0%) compared to < 5 years (17.3%) and ≥ 15 years (35.9%), subpatent infections were more likely in ≥ 15 years (70.4%) than in < 5 years (39.7%) and school-age children (41.2%). LM and RDTs were reliable only at parasite densities > 10,000 parasites/µL. Individuals who were positive according to all three tests had significantly greater parasite density (856.8 parasites/µL; 95% CI 707.3–1,038) than did those who were positive by varATS qPCR only (13.7 parasites/µL; 95% CI 11.4–16.3) (p < 0.0001). No pfhrp2 deletions were observed. The high prevalence of asymptomatic and subpatent infections highlights the need for targeted strategies to reduce malaria in urban Côte d’Ivoire.

Red blood cell dynamics during malaria infection challenge the assumptions of mathematical models of infection dynamics

Red blood cell dynamics during malaria infection challenge the assumptions of mathematical models of infection dynamics

Dynamics of IgM and IgG Antibody Response Profile against Linear B-Cell Epitopes from Exoerythrocytic (CelTOS and TRAP) and Erythrocytic (CyRPA) Phases of Plasmodium vivax: Follow-Up Study.

Malaria is a serious health problem worldwide affecting mainly children and socially vulnerable people. The biological particularities of P. vivax, such as the ability to generate dormant liver stages, the rapid maturation of gametocytes, and the emergence of drug resistance, have contributed to difficulties in disease control. In this context, developing an effective vaccine has been considered a fundamental tool for the efficient control and/or elimination of vivax malaria. Although recombinant proteins have been the main strategy used in designing vaccine prototypes, synthetic immunogenic peptides have emerged as a viable alternative for this purpose. Considering, therefore, that in the Brazilian endemic population, little is known about the profile of the humoral immune response directed to synthetic peptides that represent different P. vivax proteins, the present work aimed to map the epitope-specific antibodies' profiles to synthetic peptides representing the linear portions of the ookinete and sporozoite cell passage protein (CelTOS), thrombospondin-related adhesive protein (TRAP), and cysteine-rich protective antigen (CyRPA) proteins in the acute (AC) and convalescent phases (Conv30 and Conv180 after infection) of vivax malaria. The results showed that the studied subjects responded to all proteins for at least six months following infection. For IgM, a few individuals (3-21%) were positive during the acute phase of the disease; the highest frequencies were observed for IgG (28-57%). Regarding the subclasses, IgG2 and IgG3 stood out as the most prevalent for all peptides. During the follow-up, the stability of IgG was observed for all peptides. Only one significant positive correlation was observed between IgM and exposure time. We conclude that for all the peptides, the immunodominant epitopes are recognized in the exposed population, with similar frequency and magnitude. However, if the antibodies detected in this study are potential protectors, this needs to be investigated.

Pooled prevalence of malaria and associated factors among vulnerable populations in Ethiopia: a systematic review and meta-analysis

BackgroundMalaria is a serious, fatal disease, and a high-risk determinant for human health globally. Children, pregnant women, and migrants are vulnerable groups for malaria infection in African regions. Recently, malaria is an endemic disease in Ethiopia.ObjectivesThis study aimed to determine the pooled prevalence of malaria and its determinant factors among the most vulnerable populations in Ethiopia.MethodsElectronic databases, including PubMed, Google Scholar, Web of Science, Semantic Scholar, and Scopus were used for searching articles published since the 2020 Gregorian calendar and onwards. All peer-reviewed Ethiopian journals, health institutions, and Universities were considered for article searching. A PRISMA flow chart and Endnote software were used for article screening, and to remove duplications, respectively. The modified version of the Newcastle–Ottawa Scale was used for potential risk of bias assessments. The heterogeneity among the included studies was evaluated using the indicator of heterogeneity (I2). Egger’s test and funnel plot were used to examine the possible publication bias. A random-effects analysis was used to assess the pooled prevalence of malaria, and its determinant factors with a 95% CI. The screening process, data extraction, and quality assessment were done independently, and any disagreements were resolved through discussions.ResultsA total of twelve studies were included in this study. The pooled malaria prevalence was 11.10% (95% CI: 6.10, 16.11). Stagnant water (AOR: 4.19, 95% CI: 2.47, 7.11), no insecticide-treated net utilization (AOR: 3.15, 95% CI: 1.73, 5.73), and staying outdoors at night (AOR: 5.19, 95% CI: 2.08, 12.94) were the pooled estimated statistically risk factors for malaria prevalence. Whereas, insecticide-treated bed net utilization (AOR: 1.59, 95% CI: 0.23, 10.95) reduces the risk of malaria infection.ConclusionsThe pooled prevalence of malaria is high among vulnerable populations. Creating awareness regarding utilization of insecticide-treated bed nets, and draining stagnant water from the environment are possible interventions to reduce the prevalence of malaria.

Cryptic Congenital Malaria Infection Causing Fever of Unknown Origin in an Infant

Cryptic Congenital Malaria Infection Causing Fever of Unknown Origin in an Infant

Moving population is a challenge for malaria elimination in India: A cross-sectional study to assess malaria parasite infections in walking pilgrims in western Rajasthan, India

ObjectivesIndia is vigorously pursuing malaria elimination by 2030 and one of the key challenges is how to prevent the malaria risk associated with long-distance migrations of populations from endemic to non-endemic areas. Millions of pilgrims walking to the holy Ramdevra temple stay in temporary shelters along the route in district of Jaisalmer, Rajasthan state in western India. The main pilgrimage period coincides with the post-monsoon period with elevated vector densities. We investigated this situation to assess the potential risk posed by migrant pilgrims along the four highways in the temple district in disseminating malaria infections associated with their annual movements. MethodsA cross-sectional study was conducted for screening malaria in walking pilgrims from neighboring states at selected sites and a follow-up study for screening residents in Rajasthan from 2021 to 2023. The study comprises state entry routes, Ramdevra shrine, and pilgrimage route villages situated in western Rajasthan. Epidemiologic and entomologic surveillance was conducted during the “fair” period (August-September) and in pilgrimage route villages in three different seasons of the year to assess malaria in humans and the vector's infectivity. ResultsOf the 5251 individuals tested for malaria, a total of 76 (1.4%) tested positive for malaria, of whom 40.7% were infected with Plasmodium vivax (n = 31), 36.8% with P. falciparum (n = 28), and 22.3% with P. vivax and P. falciparum (n = 17). Anopheles density was highest during the fair season, peaking in August. An. stephensi exhibited a higher human blood index (0.65) than An. culicifacies (0.50). No mosquitoes were found positive for parasites. ConclusionsUp to 1.5% of pilgrims carried malaria parasites, posing a risk of spreading malaria to surrounding communities that otherwise would have low or no malaria burden. Moving populations pose the risk of local malaria transmission and reintroduction to the areas undergoing elimination. Sentinel point surveillance at the border of states will be helpful for states to share information on malaria and subsequently for the prevention of malaria transmission.

Beta vulgaris Betalains Mitigate Parasitemia and Brain Oxidative Stress Induced by Plasmodium berghei in Mice.

Although many drugs have been discovered to treat malaria infection, many of them face resistance from the host's body with long-term use. Therefore, this study aimed to evaluate the activity of betalains (from Beta vulgaris) and chloroquine (a reference drug) against brain oxidative stress induced by Plasmodium berghei in male mice. Two protocols were applied in this study: the therapeutic and prophylactic protocols. The results of the therapeutic protocol revealed a significant decrease in the level of parasitemia caused by P. berghei. Additionally, the histopathological changes in various brain regions were markedly improved after treatment with betalains. Regarding the prophylactic protocol, betalains were able to protect the brain tissues from oxidative stress, inflammation, and disrupted neurotransmitters expected to occur as a result of infection by P. berghei. This was demonstrated by modulating the activities of brain antioxidants (SOD and GSH), inflammatory cytokines (IL-6, IL-10, IL-12, TNF-α, and INF-γ), and neurotransmitters (serotonin, epinephrine, and norepinephrine). This study has proven that using betalains as a treatment or as a preventive has a vital and effective role in confronting the brain histopathological, oxidative stress, and inflammatory changes induced by P. berghei infection.

Interplay Between Infant Nutrition and Malaria Susceptibility in West Africa: Socioeconomic, Environmental, and Cultural Perspectives

In West Africa, infant nutrition plays a pivotal role in determining susceptibility to malaria, a disease that remains a leading cause of child mortality in the region. This review explores the intricate interplay between malnutrition and malaria susceptibility among infants, emphasizing the influence of socioeconomic, environmental, and cultural factors. Malnutrition, particularly protein-energy malnutrition and micronutrient deficiencies, compromises immune function, rendering infants more vulnerable to malaria infections. Conversely, malaria exacerbates nutritional deficiencies, creating a vicious cycle that severely impacts infant health and development. This review examines how traditional beliefs, maternal education, and family dynamics shape infant feeding practices, thereby influencing nutritional status and malaria risk. It also highlights the significance of breastfeeding, the timing of complementary feeding, and the quality of complementary foods in protecting infants against malaria. The review underscores the need for targeted nutritional interventions, such as micronutrient supplementation, fortified foods, and community-based nutrition programs, which are essential in reducing the dual burden of malnutrition and malaria. These interventions must be culturally sensitive and context-specific to effectively improve health outcomes for infants in West Africa. Further, this review illuminates the complex relationship between infant nutrition and malaria susceptibility, advocating for integrated public health strategies that address both malnutrition and malaria within the unique socio-cultural and economic landscape of West Africa. Keywords: Infant Nutrition, Malaria Susceptibility, West Africa, Socioeconomic.

High prevalence and risk factors associated with asymptomatic malaria among children in Nkwen village, Northwest Region, Cameroon

BackgroundIn endemic locations, asymptomatic malaria is a major contribution to the rise in clinical malaria. In order to achieve the goal of interrupting malaria transmission, control programmes should take into consideration carriers of asymptomatic malaria parasite. Hence, the purpose of this study was to look at the prevalence and risk factors of asymptomatic malaria in children in Nkwen village.MethodsUsing a cross-sectional and community-based design, conducted between June and December 2022, a total of 246 children were enrolled after obtaining informed and signed consent from parents and/ or guardians. To collect data, pre-tested, closed-ended, structured questionnaires were used, ensuring the accuracy and reliability of the information gathered. A digital thermometer with infrared forehead capability was used to take participants’ body temperature, providing precise measurements and respondents with temperature < 37.5 °C, and not presenting any symptoms or indicators of malaria were included in the study, ensuring the focus on asymptomatic cases. Blood samples were collected by venipuncture and screened for the presence of asymptomatic parasitaemia using blood smear microscopy and nested polymerase chain reaction (PCR). Data was entered into Microsoft Excel worksheet and analysed using SPSS version 23 software. Logistic regression models were carried out to explore the risk factors associated with asymptomatic malaria at household and individual levels and statistically significant association was considered at a p-value < 0.05.ResultsA total of 246 healthy children were examined for asymptomatic malaria infection using microscopy and PCR. Of the examined children, 65.9% (162/246) were malaria positive by PCR while 59.3% (146/246) were malaria positive by microscopy. Considering both diagnostic methods, females had a greater prevalence of asymptomatic malaria than males. In logistic analysis, the risk of developing asymptomatic malaria was associated several factors: previous malaria episode (OR = 5.14; CI 2.94–9.01), family history of malaria (OR = 3.86; CI 2.21–6.74), homestead near swampy areas (OR = 3.56; CI 2.10–10.61), non-utilization of insecticide treated nets (OR = 4.36; CI 2.53–7.5), non-usage of indoor residual spray (IRS) (OR = 6.67; CI 3.75–11.86) and opened eaves (OR = 3.86; CI 2.21–6.74). No associations were established between asymptomatic malaria and the following factors: age group (p > 0.05), gender (p > 0.05) and type of wall construction (p > 0.05).ConclusionThe high rate of asymptomatic malaria in this study is a significant problem and may jeopardize the current malaria control effort. Personal and house-level risk factors were linked with asymptomatic malaria. Therefore, it should be considered when evaluating and restructuring more successful malaria elimination tactics to accomplish the intended goals of malaria control.

Asymptomatic Malaria Cases and Plasmodium Species among BaAka Pygmies in Central Africa.

Malaria is a significant health problem in Africa, primarily due to the Plasmodium falciparum species, but this is not the only etiological factor responsible for malaria on the continent. The goal of the present research was to describe asymptomatic malaria cases and to identify Plasmodium species responsible for malaria in the BaAka Pygmies, inhabitants of the Central African Republic (CAR). Screening was realised in the period of August-September 2021 among 308 people, including 74 children and 234 adults reporting to a healthcare facility in Monasao (southwest CAR), an area inhabited by a semi-nomadic tribe of BaAka Pygmies. The study consisted of two phases. Phase I, which was conducted in Africa, consisted of performing malaria rapid diagnostic tests (mRDTs), taking haemoglobin measurements and collecting blood samples onto Whatman FTA cards for molecular diagnostics. Phase II, which was conducted in Poland, involved molecular tests (RT-PCR) to confirm or rule out malaria infections and to identify Plasmodium species responsible for the infections. mRDTs detected Plasmodium infections in 50.3% of children and 17.1% of adults participating in the study, whereas RT-PCR assays yielded positive results for 59.5% children and 28.6% adults. Molecular tests detected multiple Plasmodium falciparum infections but also three infections with P. malariae, three with P. ovale and one with P. vivax. The obtained results have confirmed numerous asymptomatic Plasmodium infections among the BaAka Pygmies. The rates of asymptomatic malaria cases in adults were twice as high as those in children, which may be indicative of the gradual acquisition of protective immunity with age. The study findings have also demonstrated that although most cases of malaria in Africa are caused by P. falciparum, three other species are also present in the region.

Spatiotemporal analysis of malaria in the state of Mato Grosso-Legal Amazon, Brazil: identification of high-risk áreas

The objective of the study was to analyze temporal and geographic data to identify high-risk areas for malaria occurrence in the state of Mato Grosso within the Legal Amazon. High-risk areas were identified through scan statistics, and the relative risk (RR) was characterized using cluster maps. Statistical temporal trend analysis was conducted using Prais-Winsten autoregression. A total of 20,819 cases were identified, with higher incidence rates among men. Malaria was predominantly diagnosed via thick blood smear microscopy, with Plasmodium vivax being the most prevalent species. The average incidence ranged from 0.01 to 2,849.85, with higher averages observed in the North, West, and Northwest regions. The Global Moran analysis revealed a positive correlation (0.47) between incidence rates and regions with a higher number of cases, while Local Moran identified distinct infection clusters. Eight risk clusters were delineated using scan statistics, with the highest RR recorded at 90.09. The spatiotemporal scan classified three statistically significant high-risk clusters exhibiting stationary temporal trends. These findings highlight the delineation of high-risk areas for malaria infection in Mato Grosso.

Malaria burden and residual transmission: two thirds of mosquito bites may not be preventable with current vector control tools on Bioko Island, Equatorial Guinea

ObjectivesThis study assesses exposure to malaria vector mosquitos that is nonpreventable through use of nets, the contribution of outdoor and indoor biting towards residual vector exposure, and the risk factors for being bitten and for being infected with malaria parasites on Bioko Island, Equatorial Guinea. MethodsHuman behavior and malaria infection data were collected from 13,735 randomly selected residents during cross-sectional surveys, concomitantly with entomological human landing catches, indoors and outdoors, in 20 locations on the Island. Self-reported time of going indoors, going to bed and whether using a net were analyzed to impute for each respondent the number of bites received outdoors and indoors during the night before the survey. ResultsOn average, each person received 2.7 (95% CI: 2.6-2.8) bites per night outdoors, 8.5 (8.3 to 8.7) bites indoors if not using a net, and 4.7 (4.5 to 4.8) bites indoors if using a net. Malaria infection was associated with more bites, regardless of whether received indoors or outdoors. Older age, male gender, not using a net, rural location, and going indoors later increased the risk of being bitten. The proportion of bites not averted by using a net was estimated as 66% (61 to 71). ConclusionsA large proportion of biting, mostly indoors, may not be preventable by bednets. Tools targeting indoor biting should be prioritized in Bioko. Novel vector control tools are urgently needed to reduce overall exposure to mosquito bites.

Living Conditions and Malaria: A Longitudinal Study in a Rural Malaria-Endemic Area of Sri Lanka.

This study was conducted in a rural malaria-endemic community in Sri Lanka in 2014-2015 because malaria was no longer endemic in the area as of November 2012. Data on sociodemographic factors, living conditions, malaria infections, and use of mosquito protection methods during the period from 1990 to 2015 were collected through a household survey in a systematically selected sample of 724 households, covering >10% of the population in the area. Malaria incidence data were obtained from Anti-Malaria Campaign, and Malaria Research Unit of the University of Colombo. A total of 24,549 malaria cases were reported and a considerable improvement in living conditions was noted during the period covered. The association of malaria case incidence with living conditions of the community was evaluated using Spearman Rank Correlation at P <0.05. Sixty-six percent of households reported a history of malaria. The percentage of poorest type of houses (type 1) declined from 38.8% in the 1990-1994 period to 1.6% by 2015, whereas the best houses (type 5) doubled from 49.1% to 92.1% during the same period. Malaria case incidence was reported to be lowest in the best type houses (r = -0.933, P = 0.007), when pipe-borne water was available within the premises (for drinking: r = -0.846, P = 0.034; for personal hygiene: r = -0.859, P = 0.029), when water-sealed sanitary facilities were available (r = -0.956, P = 0.003), and when mosquito nets were used (r = -0.98, P = 0.001). This observed negative association may have been due to reduced human-mosquito contact.

Thrombocytopenia in Plasmodium vivax Malaria: A Report from a Sub-zonal Hospital in Western Rajasthan

Abstract Background: Malaria continues to be a major public health problem in India. Vivax malaria is being increasingly seen with thrombocytopenia. The reported prevalence of the same has been extremely variable and its significance is not well established. This study was conducted to ascertain the prevalence and severity of thrombocytopenia in vivax malaria and assess the outcome of cases with severe thrombocytopenia. A secondary objective was to compare the clinical and laboratory profile of cases of vivax malaria with falciparum malaria and mixed infection. Materials and Methods: This hospital-based prospective study was carried out in the department of general medicine at a sub-zonal hospital in Western Rajasthan in the year 2022. Consecutive febrile patients with a diagnosis of malaria were included in the study after ruling out coexistent alternate infections. Results: A total of 396 cases were enrolled. Ninety-nine percent of patients were male. The mean age of the study group was 32.1 years. A total of 328 (90.8%) out of 361 vivax malaria cases had thrombocytopenia (platelet count &lt;150 × 103 μL) with 26.5% having severe thrombocytopenia (platelet count &lt;50 × 103 μL). The mean defervescence duration was 44.4 h in vivax malaria. 3.4% of severe vivax malaria cases required intensive care unit care due to hypotension, respiratory distress, and multiorgan dysfunction, and none of them had any bleeding manifestations. All cases recovered well after standard treatment. There was a significant statistical difference between the mean platelet count among the three types of malaria: vivax, falciparum, and mixed (vivax + falciparum infections) (P = 0.03). Similarly, on applying Chi-square test, there was a significant difference in severe thrombocytopenia across the groups (P = 0.01). Conclusion: There is a high prevalence of thrombocytopenia in vivax malaria including severe thrombocytopenia. In the majority of cases, this thrombocytopenia does not result in any adverse event, and cases respond well to conventional treatment. Clinicians need to be aware of the extent and severity of thrombocytopenia in vivax malaria and rule out this treatable condition in endemic areas with a high prevalence of other coexistent infections causing thrombocytopenia.

Effect of seasonal variability on the increased malaria positivity rate in drought-prone malaria endemic areas of Ethiopia.

Malaria is a climate-sensitive and season-dependent disease that mainly affects the populations of tropical and subtropical regions of the world. Climatic variables such as rainfall, temperature, and humidity are identified as the driving factors affecting the epidemiology of malaria. In Ethiopia, recently unexpectedly high malaria burden accompanied by substantial morbidity and mortality is observed. The incidence rate of vector-borne diseases such as malaria is largely influenced by fluctuation of seasonal variables due to the proceeding global warming. Therefore, the study aimed to assess the impact of seasonal and climate variability on the burden of malaria in one of drought-prone areas of north central Ethiopia. The study was conducted in the Oromia zone of the Amhara regional state in Ethiopia. Data from patients tested and diagnosed with malaria between 2014 and 2019 were extracted from the medical records of the patients registered in all health facilities found in the zone. Additionally, meteorological data such as rainfall and temperature (maximum and minimum) were collected from the regional meteorological agency. Data were analyzed using R software. The malaria positivity rate recorded in this study was 12.7% (64,522/508,057). Months from June to December were significantly (p < 0.05) associated with high malaria positivity. Rainfall had a significant negative effect on malaria positivity (p = 0.042). Also, three to four months of lagged rainfall is associated with high malaria positivity (p < 0.05). However, monthly minimum temperature positivity influenced the rate of malaria positivity (exp = 0.037, p = 0.0098). While monthly mean maximum temperature showed a negative association with malaria positivity, although it was insignificant. In addition, malaria positivity significantly decreased from 2014 to 2019 by 20.5% (exp = 0.205, p < 0.0001). The seasonal and climatic variables evaluated in this study substantially affected the malaria positivity rate. Monthly mean temperature was the leading and predictor variable for malaria infection. Despite vigorous efforts by health authorities in the country at this level, following the neglected implementation of interventional activities in the nation for a couple of years, malaria-associated burdens have increased. As seasonal and climate variables could play a key role in the rising burden, concerned national or local health authorities, and policymakers should prioritize urgent interventional activities to control malaria in one of the drought-prone areas of Ethiopia.

Prevalence of Plasmodium and Soil-Transmitted Helminth Coinfection and Associated Factors among Malaria-Suspected Patients Attending Shewa Robit Health Center, North-Central Ethiopia.

Plasmodium and soil-transmitted helminth (STH) coinfection is a major public health problem in developing countries. Its prevalence and associated factors are poorly addressed in the available research. Therefore, this study aimed to assess Plasmodium-STH coinfection prevalence and associated factors among malaria-suspected patients attending Shewa Robit Health Center, north-central Ethiopia. A cross-sectional study was conducted among 379 malaria-suspected patients attending Shewa Robit Health Center from April to May 2023. Stool and blood samples were collected from each participant. Plasmodium and STHs were detected from blood and stool samples by using blood film and the Kato-Katz method, respectively. Data were entered into Epi Info version 7 and analyzed by SPSS version 26. Descriptive statistics were used to compute Plasmodium-STH coinfection. Logistic regression was used to identify associated factors. Variables with a P-value <0.05 were considered statistically significant. Among the study participants, 27.9%, 20.3%, and 13.4% were positive for Plasmodium, STHs, and Plasmodium-STH coinfection, respectively. The prevalence of Plasmodium-Ascaris lumbricoides coinfection was high (7.6%). Unavailability of insecticide-treated bed nets (ITNs), improper use of ITNs, absence of indoor residual spraying, presence of stagnant water, and previous malaria infection were significantly associated (P <0.01) with Plasmodium infection. Being illiterate, using an unimproved latrine, having an untrimmed fingernail, and practicing open defecation were also significantly associated (P <0.03), with STH infection. Being male, illiterate, and living in rural areas were significantly associated (P <0.03) with Plasmodium-STH coinfection. The prevalence of Plasmodium-STH coinfection was high in malaria-endemic areas. Therefore, malaria-suspected cases should be checked for STH infection.

Obesity, diabetes, Plasmodium infection, and severe malaria in adults: A systematic review and meta-analysis.

This study aimed to investigate existing evidence regarding the associations of obesity and diabetes with Plasmodium infection and severe malaria in adults. We comprehensively searched relevant studies using EMBASE, MEDLINE, Global Health, and CINAHL. The primary exposures were obesity and diabetes. The primary outcomes were Plasmodium infection and severe malaria. We performed meta-analyses to pool unadjusted and adjusted odds ratios (ORs) using a random-effects model. We found 9 studies that met our inclusion criteria; all these studies were eligible for meta-analyses. None of the 9 studies investigated the potential link between obesity and Plasmodium infection. The meta-analysis results showed that there was no statistically significant relationship between obesity and severe malaria (two studies), diabetes and Plasmodium infection (five studies), or diabetes and severe malaria (three studies). Our study findings showed that obesity was not associated with severe malaria, and diabetes was not associated with neither Plasmodium infection nor severe malaria. Additional epidemiological studies should be conducted to elucidate the relationships between obesity, diabetes, and Plasmodium infection.