Epidemiology of malaria in endemic areas

Spatial distribution and geospatial modeling of potential spread of secondary malaria vectors species in Nigeria using recently collected empirical data

In Nigeria, most research and malaria vector control efforts have focused on primary vectors within the Anopheles gambiae complex, with less emphasis on other secondary vectors. Consequently, understudied secondary vectors have demonstrated a proportional and increasing role in transmission. This study utilized geospatial models to understand the potential distribution of anopheline species other than An. gambiae complex (non-gambiae species) in Nigeria. Adult mosquitoes were sampled monthly between 2020 and 2022, with concurrent surveys of larval sites in selected Local Government Areas (LGAs) across 20 States resulting in the collection and identification of over 100,000 Anopheline mosquitoes. Utilizing 23 environmental variables, the model produced maps depicting the potential geographical distribution of four secondary vector species under current climatic conditions. An. funestus, An. coustani, An. maculipalpis, and An. rufipes dominated collections, with other species also present. Most species collected exhibited higher occurrences in the Northern parts of the country, albeit with lower numbers, while they seem confined to fewer locations in the southern parts - with higher densities. An. funestus, An. maculipalpis, and An. rufipes demonstrated a higher potential for wide range expansion compared to An. coustani based on the model. Overall, modeling outputs indicate that non-An. gambiae were expected to exhibit a wide-spread across the country, with their distribution primarily influenced by temperature rather than precipitation-related factors. These models provide research scientists and decision-makers with a baseline for research, monitoring towards establishing management plans for future national mosquito surveillance and control programs in Nigeria.

Current Developments in Malaria Vaccination: A Concise Review on Implementation, Challenges, and Future Directions

Introduction

Malaria remains a persistent challenge in global health, disproportionately affecting populations in endemic regions (eg, sub-Saharan Africa). Despite decades of international collaborative efforts, malaria continues to claim hundreds of thousands of lives each year, with young children and pregnant women enduring the heaviest burden. This concise review aimed to provide an up-to-date assessment of malaria vaccines progress, challenges, and future directions.

Methods

A PubMed/MEDLINE search (2015-2024) was conducted to identify studies on malaria vaccine development, implementation barriers, efficacy, and vaccination hesitancy. Clinical trials, reviews, and global health reports were included based on relevance to the review aims. No strict inclusion criteria were applied, and selection was guided by key review themes and policy relevance.

Results

The introduction of pre-erythrocytic malaria vaccines (RTS,S/AS01 and R21/Matrix-M), represents an important milestone in malaria control efforts with promising results from the erythrocytic vaccine RH5.1/Matrix-M in recent clinical trials. However, the approval of these vaccines is accompanied by significant challenges such as the limited efficacy, the complexity of multi-dose regimens, and numerous barriers to widespread implementation in resource-limited settings. The review identified the complex challenges to broad malaria vaccination coverage, including logistical barriers, healthcare infrastructure effect, financial limitations, malaria vaccine hesitancy, among other obstacles in malaria-endemic regions. Promising developments in malaria vaccination, such as next-generation candidates (eg, mRNA-based vaccines), hold the potential to offer improved efficacy, longer-lasting protection, and greater scalability. There is a critical need to integrate malaria vaccination efforts with established malaria control interventions (eg, insecticide-treated bed nets, vector control strategies, and anti-malarial drugs).

Conclusion

Achieving sustained control of malaria morbidity and mortality will require strong global collaboration, sufficient funding, and continuous efforts to address inequities in access and delivery of malaria control measures including the malaria vaccines.

A Robust Malaria Cell Detection Framework Using Adaptive and Atrous Convolution-Based Recurrent Mobilenetv2 with Trans-MobileUNet + + -Based Abnormality Segmentation

The highly contagious malaria disease is spread by the female Anopheles mosquito. This disease results in a patient's death or incapacity to move their muscles, if it is not appropriately identified in the early stages. A Rapid Diagnostic Test (RDT) is a frequently used approach to find malaria cells in red blood cells. However, it might not be able to identify infections with small amounts of samples. In the microscopic detection model, blood stains are placed under a microscope for diagnosing malaria. But accurate diagnosis is hard in this method, particularly in developing nations where the disease is most common. The microscopic detection processes are expensive and time-consuming due to the usage of microscopes. The quality of the blood smears and the availability of a qualified specialist, who is skilled in recognizing the disease, impact the accuracy of malaria detection results. The traditional deep learning-based malaria identification models need more processing power. Therefore, a deep learning-based adaptive method is designed to detect malaria cells through the medical image. Hence, the images are gathered from the standard sites and then fed to the segmentation process. Here, the abnormality segmentation is carried out with the help of a developed Trans-MobileUNet + + (T-MUnet + +) network. Trans-MobileUNet + + captures global context, so it is well-suited for segmentation tasks. The segmented image is applied to the adaptive detection phase where the Adaptive and Atrous Convolution-based Recurrent MobilenetV2 (AA-CRMV2) model is designed for the effective recognition of malaria cells. The efficiency of the designed approach is elevated by optimizing the parameters from the AA-CRMV2 network with the help of the Updated Random Parameter-based Fennec Fox Optimization (URP-FFO) algorithm. Several experimental analyses are evaluated in the implemented model over classical techniques to display their effectualness rate.

Coverage and determinants of Intermittent Preventive Treatment in pregnancy (IPTp) in Cameroon, Guinea, Mali, and Nigeria

INTRODUCTION

Malaria poses a serious issue for pregnant women in African regions. It is crucial to comprehend the various factors that impact receiving IPTp during ANC checkups. These are important for the well-being of both pregnant mothers and their unborn children. Therefore, this study aims to investigate the determinants of IPTp coverage among women in Cameroon, Guinea, Mali, and Nigeria.

METHODOLOGY

This cross-sectional study utilized secondary data from the Malaria Indicator Surveys (MIS) across Cameroon, Guinea, Mali, and Nigeria, focusing on women who received IPTp during pregnancy with IPTp categorized dichotomously as "Yes" for ANC visits and "No" for other visits. Chi-squared tests were used to assess associations, and binary logistic regression was conducted to calculate adjusted odds ratios, confidence intervals, and p-values. Results were summarized in tables.

RESULTS

We found IPTp coverage during ANC visits was highest in Cameroon (98.6%), followed by Guinea (97.7%), Mali (97.1%), and lowest in Nigeria (95.5%). In Guinea, rural women were less likely to receive IPTp than urban women (AOR: 0.16, 95% CI: 0.07-0.41, p<0.001). In Mali, women who received 3 or more doses were less likely to receive IPTp at ANC (AOR: 0.48, p<0.01). In Nigeria, personal transport increased IPTp uptake (AOR: 1.88, p<0.01). In Cameroon, malaria prevention messages improved IPTp coverage (AOR: 3.12, p<0.05).

CONCLUSIONS

This study highlights significant disparities in IPTp uptake, with rural Mali and Guinea facing lower coverage. In Nigeria, personal transport improved IPTp uptake. Targeted interventions are needed to improve ANC services and ensure equitable IPTp access across the study regions.

An Uncommon Case of Plasmodium vivax Malaria with Disseminated Intravascular Coagulation: Rare Case Report with Review of Literature

ABSTRACT

Malaria is a severe health issue in India despite government efforts. Malaria has many complications, some of which can be life-threatening. Disseminated intravascular coagulation (DIC) is a prominent malaria complication, besides renal failure, cerebral malaria, pulmonary edema, and anemia. We report a young man with Plasmodium vivax malaria who developed septic shock due to DIC. A 25-year-old male had a fever, abdominal pain, vomiting, and nausea for 5 days. On clinical examination, the patient was in distress and had a fever of 102.6°F with a blood pressure of 86/46 mmHg. A complete blood count revealed anemia, leukocytopenia, and severe thrombocytopenia. Peripheral blood smear findings showed a P. vivax parasite in red blood cells with the presence of a few schistocytes. Further coagulation tests showed raised prothrombin, partial thromboplastin time, and d-dimer. DIC and septic shock required critical care unit admission. Conservative treatment with artesunate and lumefantrine completely cured him. This unusual case shows that P. vivax causes severe malaria and its morbid consequences. It stresses early diagnosis and treatment to prevent mortality and morbidity.

Malaria prevalence and associated population and ecological risk factors among women and children under 5 years in Rwanda

Background

Malaria continues to pose a substantial public health concern in Rwanda, despite substantial progress in recent years. Little is known about effect of ecological factors and their interaction in malaria transmission. Understanding the prevalence and identifying risk factors, both population-based and ecological such as zooprophylaxis and irrigation are crucial for targeted intervention strategies.

Methods

This study analyzed the 6th iteration of the Demographic and Health Survey conducted in Rwanda between 2019 and 2020. The study employed a nationally representative sample, utilizing rapid diagnostic tests and blood smear microscopy to determine malaria prevalence among women and under 5 years old children. Logistic regression analysis was used in R version 4.3.1 to evaluate population and ecological risk factors that are associated with malaria prevalence. Additionally, interactive effects of ecological factors on malaria were evaluated.

Results

The analysis revealed a notable malaria prevalence in Rwanda, emphasizing the continued significance of malaria control efforts. Approximately 1.79 % of the population tested positive for malaria. Proximity to irrigation sites and lowland were identified as significant risk factors to malaria with adjusted odds ratio (AOR) 1.47(1.00-2.15) and AOR 5.44(4.01-8.61) respectively however cattle ownership exhibited a protective effect AOR 0.41(0.23-0.72). Interactive effects of livestock and irrigation on malaria prevalence were revealed. Additionally, population-based risk factors, including age, household wealth, utilization of Insecticide Treated Nets, were associated with varying malaria risks.

Conclusion

This study underscores the persistent challenge of malaria in Rwanda and the importance of tailored intervention strategies. To effectively combat malaria, efforts must consider the interplay of ecological factors, such as high cattle density, and demographic factors, targeting high-risk populations, especially those living in proximity to lowlands and irrigation areas. These findings provide critical insights for advancing malaria elimination efforts in Rwanda and serve as a basis for comprehensive public health planning and action.

The Paradigm Shift of Using Natural Molecules Extracted from Northern Canada to Combat Malaria

Parasitic diseases, such as malaria, are an immense burden to many low- and middle-income countries. In 2022, 249 million cases and 608,000 deaths were reported by the World Health Organization for malaria alone. Climate change, conflict, humanitarian crises, resource constraints and diverse biological challenges threaten progress in the elimination of malaria. Undeniably, the lack of a commercialized vaccine and the spread of drug-resistant parasites beg the need for novel approaches to treat this infectious disease. Most approaches for the development of antimalarials to date take inspiration from tropical or sub-tropical environments; however, it is necessary to expand our search. In this review, we highlight the origin of antimalarial treatments and propose new insights in the search for developing novel antiparasitic treatments. Plants and microorganisms living in harsh and cold environments, such as those found in the largely unexploited Northern Canadian boreal forest, often demonstrate interesting properties that are not found in other environments. Most prominently, the essential oil of Rhododendron tomentosum spp. Subarcticum from Nunavik and mortiamides isolated from Mortierella species found in Nunavut have shown promising activity against Plasmodium falciparum.

Genetic diversity of Plasmodium vivax among immigrant patients exhibiting severe and non-severe clinical manifestations in northern suburbs of Paris

Plasmodium vivax is the most frequent and widely distributed cause of recurring malaria. It is a public health issue that mostly occurs in Southeast Asia, followed by the Middle East, Latin, and South Americas and sub-Saharan Africa. Although it is commonly known as an etiologic agent of malaria with mild clinical manifestations, it can lead to severe complications. It has been neglected and understudied for a long time, due to its low mortality, culturing infeasibility, and mild clinical manifestations in comparison to P. falciparum. Despite the mild clinical issues commonly rose for P. vivax , the correlation between the clinical manifestations exhibited by patients with severe and non-severe complications and the genetic diversity of parasites responsible for the disease is not clear. An investigation was carried out between 2011 and 2021 on patients referred to Avicenne Hospital for suspected P. vivax infection. Upon arrival, they underwent clinical and biological examinations. The lateral flow test and LAMP-PCR confirmed the presence of malaria parasites, Plasmodium sp‥ Microscopic examination revealed the presence of Plasmodium parasites with a parasitaemia between 0.01 and 0.38%. Conventional PCR amplifications targeting 714 bp DNA fragment of small subunit ribosomal DNA (SSU-rDNA) followed by bidirectional sequencing allowed us to identify the parasites as P. vivax. The neighbor-joining (NJ) phylogenetic tree revealed that P. vivax sequences processed in the present study clustered in two well-differentiated and supported clades. It included a bigger clade including P. vivax specimens of all our patients together with homonymous sequences from Indonesia, India, and El Salvador and the second clade encompassed the sequences from Yemen and India. In addition, the clustering displayed by the median-joining network agreed well with the topology of the phylogenetic tree generated by the neighbor-joining analysis. No correlation between the clinical manifestation of patients with severe and non-severe complications, encompassing diverse geographical origins, and the genetic diversity of parasites was observed since all sequences demonstrated a high homogeneity. These findings can be helpful in getting knowledge about the population genetics of P. vivax and taking proper control management strategies against these parasites.

A rare sugar, allose, inhibits the development of Plasmodium parasites in the Anopheles mosquito independently of midgut microbiota

A rare sugar, allose, was reported to inhibit the development of Plasmodium parasites in Anopheles mosquitoes; however, the mechanism remains unknown. The present study addressed the inhibitory mechanism of allose on the development of the Plasmodium parasite by connecting it with bacteria involvement in the midgut. In addition, further inhibitory sugars against Plasmodium infection in mosquitoes were explored. Antibiotic-treated and antibiotic-untreated Anopheles stephensi were fed fructose with or without allose. The mosquitoes were infected with luciferase-expressing Plasmodium berghei, and parasite development was evaluated by luciferase activity. Bacterial composition analysis in gut of their mosquitoes was performed with comprehensive 16S ribosomal RNA sequencing. As the result, allose inhibited the development of oocysts in mosquitoes regardless of prior antibiotic treatment. Microbiome analysis showed that the midgut bacterial composition in mosquitoes before and after blood feeding was not affected by allose. Although allose inhibited transient growth of the midgut microbiota of mosquitoes after blood feeding, neither toxic nor inhibitory effects of allose on the dominant midgut bacteria were observed. Ookinete development in the mosquito midgut was also not affected by allose feeding. Additional 15 sugars including six monosaccharides, four polyols, and five polysaccharides were tested; however, no inhibitory effect against Plasmodium development in mosquitoes was observed. These results indicated that allose inhibits parasite development in midgut stage of the mosquito independently of midgut microbiota. Although further studies are needed, our results suggest that allose may be a useful material for the vector control of malaria as a "transmission-blocking sugar."

Residual insecticide surface treatment for preventing malaria: a systematic review protocol

INTRODUCTION

Malaria presents a significant global public health burden, although substantial progress has been made, with vector control initiatives such as indoor residual surface spraying with insecticides and insecticide-treated nets. There now exists many different approaches to apply residual insecticide to indoor and outdoor surfaces in malaria-endemic settings, although no comprehensive systematic reviews exist evaluating these interventions. This manuscript outlines the protocol for a systematic review which aims to synthesise the best available evidence regarding full or partial indoor or outdoor residual insecticide surface treatment for preventing malaria.

METHODS AND ANALYSIS

This review will comprehensively search the literature (both published and unpublished) for any studies investigating the effectiveness of residual insecticide surface treatment for malaria. Studies will be screened to meet the inclusion criteria by a minimum of two authors, followed by assessment of risk of bias (using appropriate risk-of-bias tools for randomised and non-randomised studies) and extraction of relevant information using structured forms by two independent authors. Meta-analysis will be carried out where possible for epidemiological outcomes such as malaria, anaemia, malaria-related mortality, all-cause mortality and adverse effects. Certainty in the evidence will be established with GRADE assessments.

ETHICS AND DISSEMINATION

A full review report will be submitted to the Vector Control & Insecticide Resistance Unit, Global Malaria Program, WHO. A version of this report will be submitted for publication in an open access peer-reviewed journal. The report will inform the development of WHO recommendations regarding residual insecticide treatment for malaria. This systematic review does not require ethics approval as it is a review of primary studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 293194.

Reactive Case Detection Strategy for Malaria Control and Elimination: A 12 Year Systematic Review and Meta-Analysis from 25 Malaria-Endemic Countries

Reactive case detection (RACD) is the screening of household members and neighbors of index cases reported in passive surveillance. This strategy seeks asymptomatic infections and provides treatment to break transmission without testing or treating the entire population. This review discusses and highlights RACD as a recommended strategy for the detection and elimination of asymptomatic malaria as it pertains in different countries. Relevant studies published between January 2010 and September 2022 were identified mainly through PubMed and Google Scholar. Search terms included "malaria and reactive case detection", "contact tracing", "focal screening", "case investigation", "focal screen and treat". MedCalc Software was used for data analysis, and the findings from the pooled studies were analyzed using a fixed-effect model. Summary outcomes were then presented using forest plots and tables. Fifty-four (54) studies were systematically reviewed. Of these studies, 7 met the eligibility criteria based on risk of malaria infection in individuals living with an index case < 5 years old, 13 met the eligibility criteria based on risk of malaria infection in an index case household member compared with a neighbor of an index case, and 29 met the eligibility criteria based on risk of malaria infection in individuals living with index cases, and were included in the meta-analysis. Individuals living in index case households with an average risk of 2.576 (2.540-2.612) were more at risk of malaria infection and showed pooled results of high variation heterogeneity chi-square = 235.600, (p < 0.0001) I2 = 98.88 [97.87-99.89]. The pooled results showed that neighbors of index cases were 0.352 [0.301-0.412] times more likely to have a malaria infection relative to index case household members, and this result was statistically significant (p < 0.001). The identification and treatment of infectious reservoirs is critical to successful malaria elimination. Evidence to support the clustering of infections in neighborhoods, which necessitates the inclusion of neighboring households as part of the RACD strategy, was presented in this review.

Curry Fish Extract's Antimalarial Potency in N-hexane and Ethyl Acetate Solvents using In vitro approach

The increase in malaria morbidity and mortality due to artemisinin derivative resistance was a global problem. Marine biota, curry fish or Sticophus hermanni was known to have bioactive components that are antibacterial and antifungal. The purpose of the study was to observe phytochemical tests and antimalarial activity of golden sea cucumber, curry fish using two types of solvents with different polarities using In vtro studies. The study was a true experimental study withIn vtro protocols, which included: (P1), control negative; (P2) P. falciparum medium with n-hexane extract of curry fish; (P3) P.falciparum medium with ethyl acetate extract of curry fish. The parameters were as follows: phytochemical assay, growth %, inhibitory rate, and IC50. The phytochemical analysis found various bioactive components in the ethyl acetate extract, including flavonoids, alkaloids, steroids, and tannins, whereas the n-hexane extract includes fewer active components, including flavonoids, alkaloids, steroids, and tannins. The extract's antimalarial action is demonstrated by a decrease in parasite growth, a rise in the inhibitory rate with increasing extract dose, and IC50 less than 5 µg/ml when administered with ethyl acetate and n-hexane. Both solvents in curry fish extract displayed high antimalarial activity; however, n-hexane had a lower IC50 than ethyl acetate.

Relation between Increased IL-10 Levels and Malaria Severity: A Systematic Review and Meta-Analysis

The roles of anti-inflammatory cytokines in the pathogenesis of severe malaria have been widely studied, and the role of IL-10 in the pathogenesis of severe malaria remains unclear. Therefore, we performed a systematic review and meta-analysis to determine the difference in IL-10 levels between patients with severe malaria and those with non-severe malaria. The search for relevant studies was performed using PubMed, Scopus, and Embase from 1 February 2022 to 12 February 2022. The quality of the included studies was assessed according to the guidelines of the Strengthening the Reporting of Observational Studies in Epidemiology. The random-effects model was used to estimate the pooled effect. In all, 1215 studies were identified, and 19 were included in the quantitative syntheses. The results showed that patients with severe malaria had a higher IL-10 level than those with non-severe malaria (p = 0.03, pooled standardized mean difference: 0.74, 95% CI: 0.08-1.40, I2: 97.22%, 19 studies/21 sub studies). The meta-analysis results demonstrated increased IL-10 levels in patients with severe malaria compared with those with non-severe malaria. However, with the heterogeneity of the meta-analysis results, further studies are required to confirm the changes in the IL-10 levels according to the severity of malaria and to investigate whether a combination of other severity parameters with IL-10 levels could be an alternative marker for severe malaria.

Kaempferol: Antimicrobial Properties, Sources, Clinical, and Traditional Applications

Flavonoids are a category of plant-derived compounds which exhibit a large number of health-related effects. One of the most well-known and studied flavonoids is kaempferol, which can be found in a wide variety of herbs and plant families. Apart from their anticarcinogenic and anti-inflammatory effects, kaempferol and its associated compounds also exhibit antibacterial, antifungal, and antiprotozoal activities. The development of drugs and treatment schemes based on these compounds is becoming increasingly important in the face of emerging resistance of numerous pathogens as well as complex molecular interactions between various drug therapies. In addition, many of the kaempferol-containing plants are used in traditional systems all over the world for centuries to treat numerous conditions. Due to its variety of sources and associated compounds, some molecular mechanisms of kaempferol antimicrobial activity are well known while others are still under analysis. This paper thoroughly documents the vegetal and food sources of kaempferol as well as the most recent and significant studies regarding its antimicrobial applications.

Perceived performances of peer learning and education approach on malaria prevention through primary schools communities in rural Ethiopia: Peer educators' perspectives

Background

Schools are viewed as natural hubs and an effective strategy for promoting community healthy practices such as malaria prevention and control. This study examined the perceived performance of the peer learning and education approach to malaria prevention in rural primary school communities in Ethiopia, which has thus far received little attention.

Methods

Post-intervention data were collected from 404 randomly selected peer educators between 2 April and June 2020 using a structured questionnaire. The data were analyzed using the Statistical Package for Social Sciences (SPSS) version 24.0. Multiple linear regression was used to identify independent predictors of perceived performance of school-based peer learning and educational approach. A statistically significant p-value of < 0.05 was considered statistically significant.

Results

Four hundred and one educators (99.2%) completed the interview. The mean score of perceived performance was 44.31 (SD = 6.13) which was above the expected mean level range of 11-55. Feasibility (β = 0.253, 95% CI = [0.313, 0.682]), and appropriateness (β = 0.163, 95% CI = [0.099, 0.442]) were significantly associated with perceived performance. Self-efficacy, malaria risk perception, eagerness to share and learn from each other's experiences, and preference for more than one subject were all significantly associated with perceived performance, with (β = 0.097, CI = [0.017, 0.242]), (β = 0.143, CI = [0.071, 0.233]), (β = 0.207, CI = [0.308, 0.826]) and (β = 0.075, CI = [0.084, 2.511]) at 95% CI, respectively.

Conclusions

The peer learning and education approach to malaria prevention and control in schools has a noticeably high level of perceived performance. Thus, it is recommended that when designing and implementing such programs through schools, personal and social (team) factors such as self-efficacy, risk perceptions, and peer education team spirit be considered.

Blood transfusion malaria among blood donors in the Central Blood Bank in Kassala State, Sudan

Background and aims: Although blood transfusion is generally believed to save human lives, blood can be a vehicle for the transmission of some infectious and parasitic diseases including malaria. So, this study aims to determine the prevalence of blood transfusion malaria among blood donors in the Central Blood Bank in Kassala State, according to age and blood groups. Materials and methods: A cross-sectional study was carried out in the central blood bank in Kassala State among blood donors; this study involved one hundred blood samples, collected from donors aged from 18 to 41 years.  Results: The results showed that 1 (1%) of the donors was infected with the malaria parasite. The results also showed that the species of the malaria parasite was Plasmodium falciparum; the other Plasmodium species were not found. The results revealed that most donors were blood group O, while AB was the least common blood group; the blood group that harbored the malaria parasite was blood group O, and the other blood groups tested negative. The results also showed the highest number of blood donors was found in the age group of 24-29, and the positive donor was found in the same age group.  Conclusions: Both the blood films and immune chromatography test showed one positive result for the donor and the percentage of blood transfusion malaria was 1%.

Prevalence of non-Plasmodium falciparum species in southern districts of Brazzaville in The Republic of the Congo

BACKGROUND

Although Plasmodium falciparum infection is largely documented and this parasite is the main target for malaria eradication, other Plasmodium species persist, and these require more attention in Africa. Information on the epidemiological situation of non-P. falciparum species infections is scarce in many countries, including in the Democratic Republic of the Congo (hereafter Republic of the Congo) where malaria is highly endemic. The aim of this study was to determine the prevalence and distribution of non-P. falciparum species infections in the region south of Brazzaville.

METHODS

A cross-sectional survey was conducted in volunteers living in rural and urban settings during the dry and rainy seasons in 2021. Socio-demographic and clinical parameters were recorded. Plasmodium infection in blood samples was detected by microscopic analysis and nested PCR (sub-microscopic analysis).

RESULTS

Of the 773 participants enrolled in the study, 93.7% were from the rural area, of whom 97% were afebrile. The prevalence of microscopic and sub-microscopic Plasmodium spp. infection was 31.2% and 63.7%, respectively. Microscopic Plasmodium malariae infection was found in 1.3% of participants, while sub-microscopic studies detected a prevalence of 14.9% for P. malariae and 5.3% for Plasmodium ovale. The rate of co-infection of P. malariae or P. ovale with P. falciparum was 8.3% and 2.6%, respectively. Higher rates of sub-microscopic infection were reported for the urban area without seasonal fluctuation. In contrast, non-P. falciparum species infection was more pronounced in the rural area, with the associated risk of the prevalence of sub-microscopic P. malariae infection increasing during the dry season.

CONCLUSION

There is a need to include non-P. falciparum species in malaria control programs, surveillance measures and eradication strategies in the Republic of the Congo.

Evaluation of prediction models for the malaria incidence in Marodijeh Region, Somaliland

Malaria is a major public health concern in tropics and subtropics. Accurate malaria prediction is critical for reporting ongoing incidences of infection and its control. Hence, the purpose of this investigation was to evaluate the performances of different models of predicting malaria incidence in Marodijeh region, Somaliland. The study used monthly historical data from January 2011 to December 2020. Five deterministic and stochastic models, i.e. Seasonal Autoregressive Moving Average (SARIMA), Holt-Winters' Exponential Smoothing, Harmonic Model, Seasonal and Trend Decomposition using Loess (STL) and Artificial Neural Networks (ANN), were fitted to the malaria incidence data. The study employed Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE) and Mean Absolute Scaled Error (MASE) to measure the accuracy of each model. The results indicated that the artificial neural network (ANN) model outperformed other models in terms of the lowest values of RMSE (39.4044), MAE (29.1615), MAPE (31.3611) and MASE (0.6618). The study also incorporated three meteorological variables (Humidity, Rainfall and Temperature) into the ANN model. The incorporation of these variables into the model enhanced the prediction of malaria incidence in terms of achieving better prediction accuracy measures (RMSE = 8.6565, MAE = 6.1029, MAPE = 7.4526 and MASE = 0.1385). The 2-year generated forecasts based on the ANN model implied a significant increasing trend. The study recommends the ANN model for forecasting malaria cases and for taking the steps to reduce malaria incidence during the times of year when high incidence is reported in the Marodijeh region.

Current methods for the detection of Plasmodium parasite species infecting humans

Malaria is the world’s fatal parasitic disease. The ability to quickly and accurately identify malaria infection in challenging environments is crucial to allow efficient administration of the best treatment regime for human patients. If those techniques are accessible and efficient, global detection of Plasmodium species will become more sensitive, allowing faster and more precise action to be taken for disease control strategies. Recent advances in technology have enhanced our ability to diagnose different species of Plasmodium parasites with greater sensitivity and specificity. This literature review provides a summary and discussion of the current methods for the diagnosis and identification of Plasmodium spp. in human blood samples. So far not a single method is precise, but advanced technologies give consistent identification of a Plasmodium infection in endemic regions. By using the power of the recent methods, we can provide a broader understanding of the multiplicity of infection and or transmission dynamics of Plasmodium spp. This will result in improved disease control strategies, better-informed policy, and effective treatment for malaria-positive patients.

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Summary of the methods currently available for the detection of Plasmodium spp. infecting humans.

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No single method is perfect for every application to identify Plasmodium spp.

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Newly developed methods give promise for more reliable characterisation of Plasmodium spp.

Uncovering the Burden of Dengue in Africa: Considerations on Magnitude, Misdiagnosis, and Ancestry

Dengue is a re-emerging neglected disease of major public health importance. This review highlights important considerations for dengue disease in Africa, including epidemiology and underestimation of disease burden in African countries, issues with malaria misdiagnosis and co-infections, and potential evidence of genetic protection from severe dengue disease in populations of African descent. The findings indicate that dengue virus prevalence in African countries and populations may be more widespread than reported data suggests, and that the Aedes mosquito vectors appear to be increasing in dissemination and number. Changes in climate, population, and plastic pollution are expected to worsen the dengue situation in Africa. Dengue misdiagnosis is also a problem in Africa, especially due to the typical non-specific clinical presentation of dengue leading to misdiagnosis as malaria. Finally, research suggests that a protective genetic component against severe dengue exists in African descent populations, but further studies should be conducted to strengthen this association in various populations, taking into consideration socioeconomic factors that may contribute to these findings. The main takeaway is that Africa should not be overlooked when it comes to dengue, and more attention and resources should be devoted to this disease in Africa.

Epidemiological Trends of Malaria in Five Years and under Children of Nsanje District in Malawi, 2015-2019

Background: Malaria continues to be a major public health problem in Malawi and the greatest load of mortality and morbidity occurs in children five years and under. However, there is no information yet regarding trends and predictions of malaria incidence in children five years and under at district hospital level, particularly at Nsanje district hospital. Aim: Therefore, this study aimed at investigating the trends of malaria morbidity and mortality in order to design appropriate interventions on the best approach to contain the disease in the near future. Methodology: Trend analysis of malaria morbidity and mortality together with time series analysis using the SARIMA (Seasonal Autoregressive Integrated Moving Average) model was used to predict malaria incidence in Nsanje district. Results: The SARIMA model used malaria cases from 2015 to 2019 and created the best model to forecast the malaria cases in Nsanje from 2020 to 2022. An SARIMA (0, 1, 2) (0,1,1)₁₂ was suitable for forecasting the incidence of malaria for Nsanje. Conclusion: The mortality and morbidity trend showed that malaria cases were growing at a fluctuating rate at Nsanje district hospital. The relative errors between the actual values and predicted values indicated that the predicted values matched the actual values well. Therefore, the model proved that it was adequate to forecast monthly malaria cases and it had a good fit, hence, was appropriate for this study

Redesigning Primer of ITS2 (Internal Transcribed Spacer 2) for Specific Molecular Characterization of Malaria Vectors Anopheles Species

BACKGROUND

Anopheles mosquitoes are vectors of malaria, which is a serious health issue in Indonesia. Thus, vector control is an important approach taken to overcome this disease. The first and most important step in vector control is vector identification. As some Anopheles species share similar morphological features, molecular identification helps make the process more accurate by using specific DNA sequences as molecular markers such as Internal Transcribed Spacer 2 (ITS2). Many of the available ITS2 primers are universally designed for insects and, as such, are typically less specific for identifying certain genera, such as Anopheles sp. Therefore, redesigning a specific ITS2 primer is needed for specific Anopheles identification.

OBJECTIVE

Our objective was to redesign a specific PCR primer for Anopheles species.

METHODS

The redesigned primer, named sma-ITS2, was then tested using mosquito samples from the Anopheles genus and other genera. Each mosquito was identified morphologically and their genomes were extracted. DNA samples were then amplified using the redesigned primer.

RESULTS

The sma-ITS2 primer pair was capable of amplifying ITS2 sequences from all of the Anopheles samples and unable to amplify any of the non-Anopheles samples, suggesting that it is specific to Anopheles only. ll Anopheles samples were also able to be identified, only An. indefinitus were not able to be separated from its complex species, An. vagus.

CONCLUSION

The sma-ITS2 primer pair was able to identify intra-species of Anopheles, but its efficiency in making differentiations within a species complex should be evaluated further.

Acceptability of peer learning and education approach on malaria prevention (PLEA-malaria) through primary schools communities in rural Ethiopia: peer educators' perspectives

BACKGROUND

Evidence on peer educators' experiences of implementing the school-based educational interventions on malaria prevention would be used as inputs for malaria eliminating efforts. This study explored the acceptability of the school-based peer-learning and education approach on malaria prevention (PLEA-malaria) among peer educators in Ethiopia.

METHODS

This process evaluation study was aimed to examine the success of the school-based PLEA-malaria that was implemented in 75 primary schools in Jimma from 2017 to 2019. A mixed research method was employed to collect post-intervention data from 404 peer educators and key stakeholders. Data were collected using a structured questionnaire and interview guide. Multivariable linear regression modelling was performed using SPSS software version 26.0. Atlas ti 7.5 for windows was used to analyse the qualitative data. The result was presented by triangulating the findings of the qualitative and quantitative methods.

RESULTS

The mean score (M, range = R) of acceptability of PLEA-malaria was (M = 20.20, R = 6-30). The regression modelling showed that age; (β = 0.264, 95% CI 0.266 to 0.632), GPA; (β = 0.106, 95% CI 0.008 to 0.074), parental readiness for malaria education; (β = 0.184, 95% CI 0.711 to 2.130), frequency of peer education; (β = 0.232, 95% CI 1.087 to 2.514) and team spirit; (β = 0.141, 95% CI 0.027 to 0.177) were positively associated with the acceptability while this relationship was negative for the number of ITN in the household; (β =  - 0.111, 95% CI - 1.182 to -0.13) and frequency of parent-student communication; (β =  - 0.149, 95% CI  - 1.201 to - 0.293). The qualitative study identified facilitators of PLEA-malaria (e.g. team formation process, outcome efficacy, presence of schools' structures, schools priority, and support) and barriers (e.g. low commitments, threat appraisal, response efficacy, and PLEA-malaria implementation gaps).

CONCLUSION

The results suggested that the acceptability of the school-based PLEA-malaria was higher implying the strategy is promising in promoting malaria prevention in primary schools. Considering factors related to personal, access to malaria preventive services, school system, and social support in education and behaviour change interventions would be important to improve the acceptability. The relationship about how an improvement in the level of acceptability would in turn influences malaria preventive behaviours among the students should be investigated.

Towards malaria control in Nigeria: implications of the malaria parasite rate and spleen rate among children living in a rural community in southwest Nigeria

BACKGROUND

The World Health Organization prioritizes malaria surveillance for accurate tracking of progress of intervention programmes. The malaria parasite rate (PR) and spleen rate (SR) are economical surveillance tools. There has been a global decline in the burden of malaria over the last decade, but most African countries, like Nigeria, have a slow rate of decline. There is a need for adequate malaria surveillance to guide malaria control strategies and policymaking.

METHODS

A community-based cross-sectional study was conducted among 363 children ages 1-15 y in rural southwest Nigeria. The participants' PR was determined by microscopy and the SR was determined by palpation and ultrasonography. The associations between PR and SR and other covariates were assessed.

RESULTS

The PR was 26.7% and the SR was 12.9%. There was no significant association between PR or SR across age groups, but low social class was significantly associated with PR (55 [33.5%], p=0.004) and SR (29 [17.3%], p=0.013). The odds of having splenomegaly doubled with malaria parasitaemia (odds ratio 2.03 [95% confidence interval 1.06 to 3.88).

CONCLUSIONS

The PR and SR suggest that the study area is meso-endemic. The PR in the study area was almost equal across age groups; our findings suggest there may be a need for policy review to plan malaria intervention programmes and include older children, not just children <5 y of age. Routine malaria surveillance using simple tools such as the PR and SR are necessary for reviewing malaria control programmes in the community.

Development of Cooperative Primer-Based Real-Time PCR Assays for the Detection of Plasmodium malariae and Plasmodium ovale

Plasmodium malariae and Plasmodium ovale are increasingly gaining public health attention as the global transmission of falciparum malaria is decreasing. However, the absence of reliable Plasmodium species-specific detection tools has hampered accurate diagnosis of these minor Plasmodium species. In this study, SYBR Green-based real-time PCR assays were developed for the detection of P. malariae and P. ovale using cooperative primers that significantly limit the formation and propagation of primers-dimers. Both the P. malariae and P. ovale cooperative primer-based assays had at least 10-fold lower detection limit compared with the corresponding conventional primer-based assays. More important, the cooperative primer-based assays were evaluated in a cross-sectional study using 560 samples obtained from two health facilities in Ghana. The prevalence rates of P. malariae and P. ovale among the combined study population were 18.6% (104/560) and 5.5% (31/560), respectively. Among the Plasmodium-positive cases, P. malariae and P. ovale mono-infections were 3.6% (18/499) and 1.0% (5/499), respectively, with the remaining being co-infections with Plasmodium falciparum. The study demonstrates the public health importance of including detection tools with lower detection limits in routine diagnosis and surveillance of nonfalciparum species. This will be necessary for comprehensively assessing the effectiveness of malaria interventions and control measures aimed toward global malaria elimination.

Annona muricata Linn and Khaya grandifoliola C.DC. Reduce Oxidative Stress In Vitro and Ameliorate Plasmodium berghei-Induced Parasitemia and Cytokines in BALB/c Mice

Background.

Annona muricata and Khaya grandifoliola are ethnomedicinally used for the treatment of malaria and have been experimentally shown to have an anti-plasmodial effect, but the mechanisms involved are not fully understood. This study investigated the effect of the ethanol extracts of their leaves on parasitemia, radical scavenging and cytokines in Plasmodium berghei ANKA-infected BALB/c mice.

Methods.

BALB/c mice were infected with P. berghei and treated with chloroquine, A. muricata or K. grandifoliola extract for 4 days. The percentage of parasitemia and the level of cytokine expression were determined after treatment. Trace element, phytochemical and nitric oxide (NO) scavenging activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging properties assays were done to study the antioxidant effects of AN and KG in vitro.

Results.

P. berghei consistently increased parasitemia in BALB/c mice. The tested doses (100-, 200-, and 400 mg/kg) of A. muricata and K. grandifoliola attenuated the P. berghei-induced elevation of parasitemia and cytokines (TNF-α, IL-5, and IL-6) in vivo during the experimental period, though not as much as chloroquine. Moreover, both extracts scavenged the DPPH and NO radicals, though A. muricata had more anti-oxidant effect than K. grandifoliola in-vitro.

Conclusion.

The ethanol extracts of A. muricata and K. grandifoliola reduce parasitemia in P. berghei-treated mice BALB/c by scavenging free radicals and reducing cytokines, though the extracts were not as effective as chloroquine.

Thymoquinone against infectious diseases: Perspectives in recent pandemics and future therapeutics

The recent pandemics caused by coronavirus infections have become major challenges in 21st century human health. Scientists are struggling hard to develop a complete cure for infectious diseases, for example, drugs or vaccines against these deadly infectious diseases. We have searched papers on thymoquinone (TQ) and its effects on different infectious diseases in databases like Pubmed, Web of Science, Scopus, and Google Scholar, and reviewed them in this study. To date research suggests that natural products may become a potential therapeutic option for their prodigious anti-viral or anti-microbial effects on infectious diseases. TQ, a natural phytochemical from black seeds, is known for its health-beneficial activities against several diseases, including infections. It is evident from different in vitro and in vivo studies that TQ is effective against tuberculosis, influenza, dengue, Ebola, Zika, hepatitis, malaria, HIV, and even recent pandemics caused by severe acute respiratory syndrome of coronaviruses (SARS-CoV and SARS-CoV-2). In these cases, the molecular mechanism of TQ is partly clear but mostly obscure. In this review article, we have discussed the role of TQ against different infectious diseases, including COVID-19, and also critically reviewed the future use of TQ use to fight against infectious diseases.

Zoonotic Malaria: Non-Laverania Plasmodium Biology and Invasion Mechanisms

Malaria, which is caused by Plasmodium parasites through Anopheles mosquito transmission, remains one of the most life-threatening diseases affecting hundreds of millions of people worldwide every year. Plasmodium vivax, which accounts for the majority of cases of recurring malaria caused by the Plasmodium (non-Laverania) subgenus, is an ancient and continuing zoonosis originating from monkey hosts probably outside Africa. The emergence of other zoonotic malarias (P. knowlesi, P. cynomolgi, and P. simium) further highlights the seriousness of the disease. The severity of this epidemic disease is dependent on many factors, including the parasite characteristics, host-parasite interactions, and the pathology of the infection. Successful infection depends on the ability of the parasite to invade the host; however, little is known about the parasite invasion biology and mechanisms. The lack of this information adds to the challenges to malaria control and elimination, hence enhancing the potential for continuation of this zoonosis. Here, we review the literature describing the characteristics, distribution, and genome details of the parasites, as well as host specificity, host-parasite interactions, and parasite pathology. This information will provide the basis of a greater understanding of the epidemiology and pathogenesis of malaria to support future development of strategies for the control and prevention of this zoonotic infection.

Erythrocyte miRNA regulators and malarial pathophysiology

Pathophysiology of Plasmodium falciparum and Plasmodium vivax in malaria vis a vis host and the parasite genome interactions has been deciphered recently to present the biology of cerebral malaria, severe anaemia and placental malaria. Small non-coding RNAs have exhibited their potential to be considered as indicators and regulators of diseases. The malarial pathologies and their associated mechanisms mediated by miRNAs and their role in haematopoiesis and red cell-related disorders are elucidated. Evidence of miRNA carrying exosome-like vesicles released during infection, delivering signals to endothelial cells enhancing gene expression, resulting in parasite sequestration and complications leading to pathologies of cerebral malaria are important breakthroughs. Pregnancy malaria showed Plasmodium surface antigen promoted erythrocyte sequestration in the placental intervillous space, provoking disease development and assorted complications. Syncytiotrophoblast-derived microparticles during pregnancy and fetus development may predict pathophysiological progression on account of their altered miRNA cargoes in malaria.

The high risk of malarial recurrence in patients with Plasmodium-mixed infection after treatment with antimalarial drugs: a systematic review and meta-analysis

Background

Malaria mixed infections are often unrecognized by microscopists in the hospitals, and a delay or failure to treat Plasmodium-mixed infection may lead to aggravated morbidity and increased mortality. The present study aimed to quantify the pooled proportion and risk of malarial recurrences after the treatment of Plasmodium-mixed infection. The results of the study may provide benefits in the management of Plasmodium-mixed infection in co-endemic regions.

Methods

This systematic review and meta-analysis searched the international Prospective Register of Systematic Reviews (PROSPERO; ID = CRD42020199709), MEDLINE, Web of Science, and Scopus for potentially relevant studies in any language published between January 1, 1936, and July 20, 2020, assessing drug efficacy in patients with Plasmodium-mixed infection. The primary outcome was the pooled prevalence of Plasmodium parasitemia after initiating antimalarial treatment for Plasmodium-mixed infection. The secondary outcome was the pooled risk ratio (RR) of malarial recurrence in Plasmodium-mixed infection compared with those in Plasmodium falciparum and Plasmodium vivax mono-infection. The pooled analyses were calculated by random-effects meta-analysis. After the initial treatment in different days of recurrences (≤ 28 days or > 28 days), the risk of Plasmodium parasitemia was compared in subgroup analysis.

Results

Out of 5217 screened studies, 11 were included in the meta-analysis, including 4390 patients from six countries. The pooled prevalence of all recurrences of Plasmodium-mixed parasitemia was 30% (95% confidence interval (CI) 16–43; I²: 99.2%; 11 studies). The RR of malarial recurrence within 28 days after the initial treatment (clinical treatment failure) of Plasmodium-mixed parasitemia compared with the treatment of P. falciparum was 1.22 (p: 0.029; 95% CI 1.02–1.47; Cochran Q: 0.93; I²: 0%; six studies), while there was no significant difference in the risk of recurrence 28 days after initial treatment compared with the treatment of P. falciparum (p: 0.696, RR: 1.14; 95% CI 0.59–2.18; Cochran Q < 0.05; I²: 98.2%; four studies). The subgroup analysis of antimalarial drugs showed that significant malarial recurrence within 28 days was observed in patients treated with artemisinin-based combination therapies (ACTs) with no significant heterogeneity (p: 0.028, RR: 1.31; 95% CI 1.03–1.66; Cochran Q: 0.834; I²: 0%).

Conclusions

The present findings showed a high prevalence of malarial recurrence after the initial treatment of Plasmodium-mixed infection. Moreover, significant malaria recurrence of mixed infection occurred within 28 days after treatment with ACTs.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04792-5.

Multi-Nutrient Fortified Dairy-Based Drink Reduces Anaemia without Observed Adverse Effects on Gut Microbiota in Anaemic Malnourished Nigerian Toddlers: A Randomised Dose-Response Study

Prevalence of anaemia among Nigerian toddlers is reported to be high, and may cause significant morbidity, affects brain development and function, and results in weakness and fatigue. Although, iron fortification can reduce anaemia, yet the effect on gut microbiota is unclear. This open-label randomised study in anaemic malnourished Nigerian toddlers aimed to decrease anaemia without affecting pathogenic gut bacteria using a multi-nutrient fortified dairy-based drink. The test product was provided daily in different amounts (200, 400 or 600 mL, supplying 2.24, 4.48 and 6.72 mg of elemental iron, respectively) for 6 months. Haemoglobin, ferritin, and C-reactive protein concentrations were measured to determine anaemia, iron deficiency (ID) and iron deficiency anaemia (IDA) prevalence. Faecal samples were collected to analyse gut microbiota composition. All three dosages reduced anaemia prevalence, to 47%, 27% and 18%, respectively. ID and IDA prevalence was low and did not significantly decrease over time. Regarding gut microbiota, Enterobacteriaceae decreased over time without differences between groups, whereas Bifidobacteriaceae and pathogenic E. coli were not affected. In conclusion, the multi-nutrient fortified dairy-based drink reduced anaemia in a dose-dependent way, without stimulating intestinal potential pathogenic bacteria, and thus appears to be safe and effective in treating anaemia in Nigerian toddlers.

Antimalarial Effect of the Total Glycosides of the Medicinal Plant, Ranunculus japonicus

In traditional Chinese medicine, Ranunculus japonicus has been used to treat various diseases, including malaria, and the young stem of R. japonicus is consumed as a food in the Republic of Korea. However, experimental evidence of the antimalarial effect of R. japonicus has not been evaluated. Therefore, the antimalarial activity of the extract of the young stem of R. japonicus was evaluated in vitro using both chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) strains; in vivo activity was evaluated in Plasmodium berghei-infected mice via oral administration followed by a four-day suppressive test focused on biochemical and hematological parameters. Exposure to extracts of R. japonicus resulted in significant inhibition of both chloroquine-sensitive (3D7) and resistant (Dd2) strains of P. falciparum, with IC₅₀ values of 6.29 ± 2.78 and 5.36 ± 4.93 μg/mL, respectively. Administration of R. japonicus also resulted in potent antimalarial activity against P. berghei in infected mice with no associated toxicity; treatment also resulted in improved hepatic, renal, and hematologic parameters. These results demonstrate the antimalarial effects of R. japonicus both in vitro and in vivo with no apparent toxicity.

Olfaction in Anopheles mosquitoes

As vectors of disease, mosquitoes are a global threat to human health. The Anopheles mosquito is the deadliest mosquito species as the insect vector of the malaria-causing parasite, which kills hundreds of thousands every year. These mosquitoes are reliant on their sense of smell (olfaction) to guide most of their behaviors, and a better understanding of Anopheles olfaction identifies opportunities for reducing the spread of malaria. This review takes a detailed look at Anopheles olfaction. We explore a range of topics from chemosensory receptors, olfactory neurons, and sensory appendages to behaviors guided by olfaction (including host-seeking, foraging, oviposition, and mating), to vector management strategies that target mosquito olfaction. We identify many research areas that remain to be addressed.

The New Zoonotic Malaria: Plasmodium cynomolgi

Plasmodium cynomolgi is a simian malaria parasite that has been a central model parasite since it was first described in 1907. Recently it has made the zoonotic jump and started naturally infecting humans. In this paper, the interactions between Plasmodium cynomolgi and humans, the environment and the non-human animal intermediates or definitive host will be discussed, with a particular focus on the clinical implications of infection and approaches to management of this novel zoonotic parasite.

The Epidemiology of Plasmodium falciparum Malaria in the Bijagos Islands of Guinea-Bissau

Distribution of long-lasting insecticide-treated nets (LLINs), passive detection and treatment with artemisinin-based combination therapy (ACT), and intermittent preventive treatment in pregnancy (IPTp) are the mainstay malaria control measures of Guinea-Bissau’s national control programme. This study aimed to estimate the prevalence of Plasmodium falciparum on Bubaque, the most populous island of the country’s remote Bijagos archipelago. A cross-sectional survey was performed at the start of the rainy season in August 2017. Participants were recruited using systematic random sampling in a two-stage stratified cluster design. Malaria parasitemia was detected using rapid diagnostic tests (RDTs) and quantitative PCR (qPCR). Data on housing, education, larval source management, socioeconomic status, anemia, and malaria preventive measures were collected. Multivariable logistic regression models were constructed to identify associations with P. falciparum infection. Four hundred four persons (aged 6 months–79 years, median 17 years) were enrolled in the study. The prevalence of P. falciparum parasitemia was 5.8% by RDT (95% CI: 3.55–9.33) and 16.9% by qPCR (95% CI: 13.09–21.71). The prevalence of anemia was 74.3% (95% CI: 69.04–78.85) as defined by the WHO criteria. All sampled houses were found to have open eaves; 99.5% of the surveyed population reported sleeping under a bednet (95% CI: 97.8–99.9). Although reported LLIN use is high, there remains an appreciable prevalence of malaria, suggesting that transmission is ongoing and further tools are required to reduce the burden of the disease.

Evolutionary analyses of the major variant surface antigen-encoding genes reveal population structure of Plasmodium falciparum within and between continents

Malaria remains a major public health problem in many countries. Unlike influenza and HIV, where diversity in immunodominant surface antigens is understood geographically to inform disease surveillance, relatively little is known about the global population structure of PfEMP1, the major variant surface antigen of the malaria parasite Plasmodium falciparum. The complexity of the var multigene family that encodes PfEMP1 and that diversifies by recombination, has so far precluded its use in malaria surveillance. Recent studies have demonstrated that cost-effective deep sequencing of the region of var genes encoding the PfEMP1 DBLα domain and subsequent classification of within host sequences at 96% identity to define unique DBLα types, can reveal structure and strain dynamics within countries. However, to date there has not been a comprehensive comparison of these DBLα types between countries. By leveraging a bioinformatic approach (jumping hidden Markov model) designed specifically for the analysis of recombination within var genes and applying it to a dataset of DBLα types from 10 countries, we are able to describe population structure of DBLα types at the global scale. The sensitivity of the approach allows for the comparison of the global dataset to ape samples of Plasmodium Laverania species. Our analyses show that the evolution of the parasite population emerging out of Africa underlies current patterns of DBLα type diversity. Most importantly, we can distinguish geographic population structure within Africa between Gabon and Ghana in West Africa and Uganda in East Africa. Our evolutionary findings have translational implications in the context of globalization. Firstly, DBLα type diversity can provide a simple diagnostic framework for geographic surveillance of the rapidly evolving transmission dynamics of P. falciparum. It can also inform efforts to understand the presence or absence of global, regional and local population immunity to major surface antigen variants. Additionally, we identify a number of highly conserved DBLα types that are present globally that may be of biological significance and warrant further characterization.

Effectiveness of the school-based social and behaviour change communication interventions on insecticide-treated nets utilization among primary school children in rural Ethiopia: a controlled quasi-experimental design

BACKGROUND

School-based behaviour change communication interventions could help to achieve behavioural changes in the school and enhance the enrollment of the students and teachers as health messengers to local communities. Evidence on the impacts of the school-engaged malaria preventive interventions are limited as far as the social and behaviour change communication (SBCC) is concerned. This study examined the effectiveness of the school-based SBCC approach on insecticide-treated nets (ITNs) utilization among primary school students in malaria-endemic settings of Ethiopia.

METHODS

Various participatory, educational, and communication interventions were implemented from 2017 to 2019 in 75 primary schools and respective villages in Jimma to promote malaria preventive practices. A quasi-experimental design was conducted with randomly selected 798 students (i.e. 399 intervention and 399 control groups). Data were collected by trained interviewers using structured questionnaires. The SPSS version 26 software was used to analyse the data. Propensity score matching analysis was performed to control for possible confounding biases. The average effects of the intervention were estimated using multivariate general linear modelling to estimate for mean differences and odds ratio based on the nature of data.

RESULTS

The result showed that the ITNs utilization was 6.857 folds in the intervention groups compared to the counterpart; (OR = 6.857; 95% CI: (4.636, 10.1430); effect size = 39%). A mean differences (MD) of self-efficacy (MD = 15.34; 95% CI: 13.73 to 16.95), knowledge (MD = 5.83; 95% CI: 5.12 to 6.55), attitude (MD = 6.01; 95% CI: 5.26 to 6.77), perceived malaria risk (MD = 2.14; 95% CI: 1.53 to 2.76), and perceived family supports (MD = 6.39; 95% CI: 5.57 to 7.22) were observed favoring the intervention. Multivariable logistic regression modelling results showed that knowledge (β = 0.194, 95% CI: 1.09 to 1.35) and perceived family supports (β = 0.165, 95% CI: 1.11 to 1.25) and self-efficacy (β = 0.10, 95% CI: 1.22 to 2.32) predicted the ITN utilization among the school children.

CONCLUSIONS

The finding of this study suggested that the school-based SBCC approach combined with peer education activities advanced the malaria-related knowledge, attitude, self-efficacy, risk perceptions, and family supports and ultimately improved the sustained use of ITNs among school-going children. Further research should be conducted to understand the mechanism of these effects given the influences of social, health services, and school systems are considered.

Biosensing based on field-effect transistors (FET): Recent progress and challenges

The use of field-Effect-Transistor (FET) type biosensing arrangements has been highlighted by researchers in the field of early biomarker detection and drug screening. Their non-metalized gate dielectrics that are exposed to an electrolyte solution cover the semiconductor material and actively transduce the biological changes on the surface. The efficiency of these novel devices in detecting different biomolecular analytes in a real-time, highly precise, specific, and label-free manner has been validated by numerous research studies. Considerable progress has been attained in designing FET devices, especially for biomedical diagnosis and cell-based assays in the past few decades. The exceptional electronic properties, compactness, and scalability of these novel tools are very desirable for designing rapid, label-free, and mass detection of biomolecules. With the incorporation of nanotechnology, the performance of biosensors based on FET boosts significantly, particularly, employment of nanomaterials such as graphene, metal nanoparticles, single and multi-walled carbon nanotubes, nanorods, and nanowires. Besides, their commercial availability, and high-quality production on a large-scale, turn them to be one of the most preferred sensing and screening platforms. This review presents the basic structural setup and working principle of different types of FET devices. We also focused on the latest progression regarding the use of FET biosensors for the recognition of viruses such as, recently emerged COVID-19, Influenza, Hepatitis B Virus, protein biomarkers, nucleic acids, bacteria, cells, and various ions. Additionally, an outline of the development of FET sensors for investigations related to drug development and the cellular investigation is also presented. Some technical strategies for enhancing the sensitivity and selectivity of detection in these devices are addressed as well. However, there are still certain challenges which are remained unaddressed concerning the performance and clinical use of transistor-based point-of-care (POC) instruments; accordingly, expectations about their future improvement for biosensing and cellular studies are argued at the end of this review.

Application of Epidemiological Geographic Information System: An Open-Source Spatial Analysis Tool Based on the OMOP Common Data Model

BACKGROUND

Spatial epidemiology is used to evaluate geographical variations and disparities in health outcomes; however, constructing geographic statistical models requires a labor-intensive process that limits the overall utility. We developed an open-source software for spatial epidemiological analysis and demonstrated its applicability and quality.

METHODS

Based on standardized geocode and observational health data, the Application of Epidemiological Geographic Information System (AEGIS) provides two spatial analysis methods: disease mapping and detecting clustered medical conditions and outcomes. The AEGIS assesses the geographical distribution of incidences and health outcomes in Korea and the United States, specifically incidence of cancers and their mortality rates, endemic malarial areas, and heart diseases (only the United States).

RESULTS

The AEGIS-generated spatial distribution of incident cancer in Korea was consistent with previous reports. The incidence of liver cancer in women with the highest Moran's I (0.44; p < 0.001) was 17.4 (10.3-26.9). The malarial endemic cluster was identified in Paju-si, Korea (p < 0.001). When the AEGIS was applied to the database of the United States, a heart disease cluster was appropriately identified (p < 0.001).

CONCLUSIONS

As an open-source, cross-country, spatial analytics solution, AEGIS may globally assess the differences in geographical distribution of health outcomes through the use of standardized geocode and observational health databases.

Global prevalence and mortality of severe Plasmodium malariae infection: a systematic review and meta-analysis

Background

Severe complications among patients with Plasmodium malariae infection are rare. This is the first systematic review and meta-analysis demonstrating the global prevalence and mortality of severe P. malariae infection in humans.

Methods

The systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All research articles published on the severity and mortality of P. malariae infection cases in humans were retrieved from three public databases: PubMed, Scopus, and ISI Web of Science. The pooled prevalence estimate and 95% confidence interval (CI) of complications in patients with P. malariae malaria was analysed using the random-effects model provided in Stata software. The pooled odds ratio (OR) and 95% CI of severe malaria for P. malariae infection and Plasmodium falciparum infection were analysed using Review Manager software.

Results

Six studies were used to estimate the pooled prevalence of severe P. malariae malaria. Out of 10,520 patients infected with P. malariae, the pooled prevalence estimate of severe P. malariae infection was 3% (95% CI 2–5%), with high heterogeneity (I²: 90.7%). Severe anaemia (3.32%), pulmonary complications (0.46%), and renal impairments (0.24%) were the most common severe complications found in patients with P. malariae infection. The pooled proportion of severe anaemia for P. malariae infection and P. falciparum infection was comparable among the four included studies (OR: 0.74, 95% CI 0.22–2.45, I² = 98%). The pooled proportion of pulmonary complications was comparable between patients with P. malariae infection and those with P. falciparum infection among the four included studies (OR: 1.44; 95% CI 0.17–12.31, I²: 92%). For renal complications, the funnel plot showed that the pooled proportion of renal complications for P. malariae infection and P. falciparum infection was comparable among the four included studies (OR: 0.94, 95% CI 0.18–4.93, I²: 91%). The mortality rate of patients with P. malariae infection was 0.17% (18/10,502 cases).

Conclusions

This systematic review demonstrated that approximately two percent of patients with P. malariae infection developed severe complications, with a low mortality rate. Severe anaemia, pulmonary involvement, and renal impairment were the most common complications found in patients with P. malariae infection. Although a low prevalence and low mortality of P. malariae infection have been reported, patients with P. malariae infection need to be investigated for severe anaemia and, if present, treated aggressively to prevent anaemia-related death.

Parasitic diseases as a cause of acute abdominal pain: imaging findings

Acute abdominal pain can be seen in cases with parasitic diseases delivered to emergency departments. The diagnosis of the parasitic disease can be delayed because of the similar clinical signs encountered in other frequently seen causes of acute abdomen. Nevertheless, the features detected in imaging scans can be helpful in the diagnosis. The present study aims to raise awareness about abdominal parasitosis in emergency conditions and also to underline the association between imaging findings and the life cycle of parasites with illustrative cases.

Novel Quinazolin-2,4-Dione Hybrid Molecules as Possible Inhibitors Against Malaria: Synthesis and in silico Molecular Docking Studies

The research explores the synthesis of a series of novel hybrid quinazolin-2,4-dione analogs bearing acetyl/amide bridged-nitrogen heterocyclic moieties such as azetidinone, pyrrole, oxazole, oxadiazole, thiazole, pyrazole, and thiazolidine scaffolds 2-16. The newly synthesized compounds were structurally confirmed by means of IR, ¹H-NMR, ¹³C-NMR, MS and elemental analysis. In addition, an in silico molecular docking analysis of new compounds and standard drug (Chloroquine) has been performed to analyze the binding modes of interaction to the putative active site of Plasmodium falciparum Dihydroorotate dehydrogenase (pfDHODH). Aiming to search for potentially better antimalarials, a modern approach has been undertaken to identify new quinazolin-2,4-dione derivatives targeting pfDHODH. The identification of antimalarial activity of the newly synthesized compounds by using experimental techniques is expensive and requires extensive pains and labor. The compound 11 showed the highest binding affinity against pfDHODH. Moreover, the electrostatic potential (ESP) of the docked molecules was also calculated. Further, the pharmacokinetic properties (ADMET) of the prepared compounds were predicted through in silico technique.

Impact of seasonal malaria chemoprevention in children aged 3 to 59 months in the Kangaba and Kolokani health districts between 2013 and 2015

INTRODUCTION

Malaria is a public health problem in Mali. Seasonal chemo prevention (SCP) is of particular importance, hence its introduction by the WHO since 2012 in children aged 3 to 59 months from the start of the transmission season. This study aims to demonstrate the impact of SCP on malaria in the health districts of Kangaba and Kolokani.

MATERIALS AND METHODS

Our retrospective study was carried out from 2013 to 2015 in the health districts of Kangaba and Kolokani using the databases of the NGO AMCP / ALIMA. Data from 2014 and 2015 were compared to data from 2013.

RESULTS

The number of malaria cases in children under 5year in the area covered by the SCP shows a considerable decrease in Kangaba of 52% in 2014 and 49% in 2015, compared to the reference period being the year 2013. In Kolokani the decrease is 57% in 2014 and 40% in 2015 compared to the year 2013. Compared to deaths, a decrease of 50.5% was recorded in 2014 and 60.4% in 2015 compared to the year 2013, i.e. 51 and 61 fewer deaths compared to 2013, respectively, in health facilities.

CONCLUSION

The SCP had made it possible to reduce significant mortality and malaria morbidity in the two health districts of Kangaba and Kolokani.

Detecting geospatial patterns of Plasmodium falciparum parasite migration in Cambodia using optimized estimated effective migration surfaces

BACKGROUND

Understanding the genetic structure of natural populations provides insight into the demographic and adaptive processes that have affected those populations. Such information, particularly when integrated with geospatial data, can have translational applications for a variety of fields, including public health. Estimated effective migration surfaces (EEMS) is an approach that allows visualization of the spatial patterns in genomic data to understand population structure and migration. In this study, we developed a workflow to optimize the resolution of spatial grids used to generate EEMS migration maps and applied this optimized workflow to estimate migration of Plasmodium falciparum in Cambodia and bordering regions of Thailand and Vietnam.

METHODS

The optimal density of EEMS grids was determined based on a new workflow created using density clustering to define genomic clusters and the spatial distance between genomic clusters. Topological skeletons were used to capture the spatial distribution for each genomic cluster and to determine the EEMS grid density; i.e., both genomic and spatial clustering were used to guide the optimization of EEMS grids. Model accuracy for migration estimates using the optimized workflow was tested and compared to grid resolutions selected without the optimized workflow. As a test case, the optimized workflow was applied to genomic data generated from P. falciparum sampled in Cambodia and bordering regions, and migration maps were compared to estimates of malaria endemicity, as well as geographic properties of the study area, as a means of validating observed migration patterns.

RESULTS

Optimized grids displayed both high model accuracy and reduced computing time compared to grid densities selected in an unguided manner. In addition, EEMS migration maps generated for P. falciparum using the optimized grid corresponded to estimates of malaria endemicity and geographic properties of the study region that might be expected to impact malaria parasite migration, supporting the validity of the observed migration patterns.

CONCLUSIONS

Optimized grids reduce spatial uncertainty in the EEMS contours that can result from user-defined parameters, such as the resolution of the spatial grid used in the model. This workflow will be useful to a broad range of EEMS users as it can be applied to analyses involving other organisms of interest and geographic areas.

Toward the Elimination of Malaria in China: A Retrospective Analysis of Malaria-Endemic Characteristics and Prevention Effects in Yantai, Shandong Province, 1951 to 2017

Objectives: To study the epidemiological characteristics of malaria and the effects of comprehensive malaria control implementation in Yantai, as well as to provide a scientific basis for future malaria elimination. Materials and Methods: A retrospective analysis was conducted to explore the epidemiological changes and prevention effects in Yantai from 1951 to 2017. The malaria data before 2004 were collected from paper-based annual reports, and data after 2004 came from the Infectious Diseases Information Reporting Management System. Results: A total of 81,286 malaria cases were identified in Yantai from 1957 to 2017, with two peaks occurring in 1966 (120.93/100,000) and 1970-1972 (366.12/100,000). From 1951 to 2003, the case classification was mainly Plasmodium vivax (99.80%); the first case attributed to Plasmodium falciparum occurred in 2004, and P. falciparum became the main cause of malaria after 2011. All cases reported since 2010 have been imported cases, and the last indigenous case was caused by P. vivax in 2008. A total of 129 imported cases were reported from 2010 to 2017, most of which originated in Africa (93.80%), mainly in men aged 30-49 years (68.28%). From 1951 to 1973, 73,868 cases of malaria were diagnosed with clinical symptoms, and from 1974 to 2017, 818,943 cases in fever patients were diagnosed with blood tests. Conclusions: To achieve the goal of eliminating malaria by 2020, Yantai should continue to strengthen the management of migrant population, including improving malaria surveillance for returnees and immigrants from overseas endemic areas, and continue to increase the training of medical personnel to improve their diagnostic ability.

Dengue and malaria infections in pregnancy : Maternal, fetal and neonatal outcomes at a tertiary care hospital

Background

Malaria and dengue cause major morbidity in developing nations and are more severe in pregnancy. Maternal, fetal, and neonatal outcomes in pregnant patients infected with dengue or malaria were studied.

Methods

The medical records of pregnant women admitted with either dengue or malaria infections from 2011–2015 to this hospital were reviewed. Clinical outcomes and laboratory tests were examined.

Results

Of 85 women, 56%, 21%, and 22% had contracted dengue, malaria, and multiple infections, respectively. Pregnant women who had contracted dengue fever alone were more likely to present to the hospital at an earlier gestational age (24 weeks, p = 0.03). Women with multiple infections, were more likely to deliver earlier (30 weeks, p < 0.01). Women with malaria were more likely to have low birth weight deliveries (mean birth weight 2394 g, p = 0.03). The incidence of in-hospital deaths among the cohort was 7%.

Conclusion

It is imperative to develop guidelines to screen for and diagnose dengue and malaria in pregnancy.

Electronic supplementary material

The online version of this article (10.1007/s00508-019-01606-8) contains supplementary material, which is available to authorized users.

Determinants of the persistence of malaria in Rwanda

Background

Malaria has a considerable impact on the health of the populations of developing countries; indeed, the entire population of Rwanda is at risk of contracting the disease. Although various interventions to control malaria have been implemented in Rwanda, the incidence of malaria has increased since 2012. There is an interest in understanding factors driving its persistence in Rwanda. This study aims at evaluating the effect of socio-economic and environmental factors, seasonality and the use of insecticide-treated mosquito nets (ITNs) on malaria persistence in Rwanda.

Methods

This study analysed data from the 2014–2015 Rwanda Demographic and Health Survey of 11,202 household’s members composed of children under the age of 5 and women aged between 15 and 49. Bivariate analysis was performed between the outcome and each covariate including wealth, altitude, education level, place of residence, and use of ITNs generating percentages. Chi square test was performed to compare malaria negatives and positives on each covariate. Significant variables were subjected to logistic regression analysis to evaluate factors that are significantly associated with malaria at P < 0.05. The analysis was performed in R x64 3.6 and QGIS3.6 was used to map geographical distribution of malaria cases.

Results

The lowest wealth category was associated with the incidence of malaria [AOR] = 1.54, 95% CI (1.78–2.03). Having a place of residence < 1700 m above sea level (asl) and non-use of ITNs were significantly associated with the incidence of malaria (adjusted odds ratio [AOR] = 2.93, 95% confidence interval [95% CI] 1.94–4.42 and [AOR] = 1.29, 95% C.I (1.03–1.60), respectively). Season and type of residence were not significantly associated with malaria prevalence while women had lower risk of contracting malaria than children.

Conclusion

Increased malaria prevalence was associated with lower income, non-compliance with bed-net usage and living below 1700 m of altitude. In addition to current malaria control strategies, potential interventions in individuals with lower income and areas at low altitudes should be taken into consideration when formulating malaria-control strategies, Also use of ITNs to control the spread of malaria should be emphasized.

Characterizing the Spatial Determinants and Prevention of Malaria in Kenya

The United Nations' Sustainable Development Goal 3 is to ensure health and well-being for all at all ages with a specific target to end malaria by 2030. Aligned with this goal, the primary objective of this study is to determine the effectiveness of utilizing local spatial variations to uncover the statistical relationships between malaria incidence rate and environmental and behavioral factors across the counties of Kenya. Two data sources are used-Kenya Demographic and Health Surveys of 2000, 2005, 2010, and 2015, and the national Malaria Indicator Survey of 2015. The spatial analysis shows clustering of counties with high malaria incidence rate, or hot spots, in the Lake Victoria region and the east coastal area around Mombasa; there are significant clusters of counties with low incidence rate, or cold spot areas in Nairobi. We apply an analysis technique, geographically weighted regression, that helps to better model how environmental and social determinants are related to malaria incidence rate while accounting for the confounding effects of spatial non-stationarity. Some general patterns persist over the four years of observation. We establish that variables including rainfall, proximity to water, vegetation, and population density, show differential impacts on the incidence of malaria in Kenya. The El-Nino-southern oscillation (ENSO) event in 2015 was significant in driving up malaria in the southern region of Lake Victoria compared with prior time-periods. The applied spatial multivariate clustering analysis indicates the significance of social and behavioral survey responses. This study can help build a better spatially explicit predictive model for malaria in Kenya capturing the role and spatial distribution of environmental, social, behavioral, and other characteristics of the households.

Toxicity profiling and prioritization of plant-derived antimalarial agents

Human malaria is the most widespread mosquito-borne life-threatening disease worldwide. In the absence of effective vaccines, prevention and treatment of malaria only depend on prophylaxis and drug-based therapy either in monotherapy or in combination. Unfortunately, the number of available antimalarial drugs presenting different mechanisms of action is rather limited. In addition, the appearance of drug-resistance in the parasite strains impacts the efficacy of the treatments. As a result, there is a crucial need to find new drugs to circumvent resistance problems. In the quest to identify new antimalarial agents a huge number of plant-derived compounds (PDCs) have been investigated. Surprisingly in the in silico PDC screening programs, toxicity filters are either never used or so simple that their interest is limited. In this context, the goal of this study was to show how to take advantage of validated toxicity QSAR models for refining the selection of PDCs. From an original data set of 507 PDCs collected from the literature, the use of toxicity filters for endocrine disruption, developmental toxicity, and hepatotoxicity in conjunction with classical pharmacokinetic filters allowed us to obtain a list of 31 compounds of potential interest. The pros and cons of such a strategy have been discussed.