The Global Burden of Malaria and Control Strategies

This study aimed to determine the prevalence of co-infection with malaria and intestinal parasites and assess its association with anemia in school-aged children from rural and urban settlements in Gabon. This cross-sectional study involved afebrile school children recruited at schools between May and June 2021. Blood and stool samples were collected from participants whose parents or legal guardians provided informed consent to participate in the study. Hemoglobin concentration (Hb) was measured using a HemoCue photometer (HemoCue 201, HemoCue, Angelholm, Sweden). Giemsa-stained blood films were examined to detect malaria parasites and any filarial infections, while the merthiolate-iodine concentration (MIC) method was used to identify intestinal parasitic infections (IPI). A total of four hundred and seventy (470) school-aged children were successfully enrolled in this study. The observed prevalence values were as follows: malaria infection at 69.6%, IPIs at 19.1%, filaria at 5.1%, Schistosoma infection at 15.0%, and anemia at 29.0%. Co-infections of malaria with IPIs, filaria, and Schistosoma were present in 12.3%, 4.7%, and 6.6% of the children, respectively. Malaria and filaria infections were associated with residing in Lastourville city (p < 0.05) and were also correlated with age (p < 0.05), whereas IPIs were associated with male gender and living in the city of Lastourville. Anemia was linked to malaria infection (p < 0.05) and was more prevalent among children living in rural areas. The findings of this study indicate that malaria, IPIs, and Schistosoma infections continue to pose a significant public health problem in the study area, even though only malaria infection appeared to be associated with anemia. Nevertheless, these results highlight the need for implementing control measures to reduce the prevalence of malaria, IPIs, filaria, and Schistosoma, particularly in Lastourville. Full article

Indoor residual spraying (IRS) and the use of insecticide-treated bednets for malaria vector control have contributed substantially to a reduction in malaria disease burden. However, these control tools have important shortcomings including being donor-dependent, expensive, and often failing because of insufficient uptake. We assessed the safety and efficacy of a user-friendly, locally tailored malaria vector control approach dubbed “Hut Decoration for Malaria Control” (HD4MC) based on the incorporation of a WHO-approved insecticide, Actellic^® 300 CS, into a customary hut decoration practice in rural Uganda where millions of the most vulnerable and malaria-prone populations live in mud-walled huts. Three hundred sixty households were randomly assigned to either the HD4MC (120 households), IRS (120 households) or control group without any wall treatment (120 households). Entomological indices were assessed using pyrethrum spray catching, CDC light traps and human landing catches. The Actellic^® 300 CS toxicity on acetylcholinesterase activity among applicators of HD4MC was evaluated using the Test-mate (Model 400) erythrocyte acetylcholinesterase (AChE) test V.2, whereas toxicity in household occupants was monitored clinically. The Actellic^® 300 CS level in house dust was analyzed using reversed-phase high-performance liquid chromatography (RP-HPLC). Entomological indices were compared between the three study arms at 1.5, 3 and 6 months post-intervention. HD4MC- and IRS-treated huts had a significantly reduced malaria vector density and feeding rate compared to control huts. There was no significant reduction in acetylcholinesterase activity at 1.5 and 24 h post exposure. Actellic^® 300 CS exposure did not result in any serious adverse events among the household occupants. In conclusion, HD4MC was safe and had comparable efficacy to canonical IRS. Full article

Malaria remains a significant public health problem in India. Although temperature influences Anopheline mosquito feeding intervals, population density, and longevity, the reproductive potential of the Plasmodium parasite and rainfall influence the availability of larval habitats, and evidence to correlate the impact of climatic factors on the incidence of malaria is sparse. Understanding the influence of climatic factors on malaria transmission will help us predict the future spread and intensification of the disease. The present study aimed to determine the impact of temporal trend of climatic factors such as annual average maximum, minimum, mean temperature, and rainfall on the annual incidence of malaria cases in India for a period of 61 years from 1961 to 2021 and relative humidity for a period of 41 years from 1981 to 2021. Two different analyses were performed. In the first analysis, the annual incidence of malaria and meteorological parameters such as annual maximum, minimum, and mean temperature, annual rainfall, and relative humidity were plotted separately in the graph to see if the temporal trend of climatic factors had any coherence or influence over the annual incidence of malaria cases. In the second analysis, a scatter plot was used to determine the relationship of the incidence of malaria in response to associated climatic factors. The incidence of malaria per million population was also calculated. In the first analysis, the annual malaria cases showed a negative correlation of varying degrees with relative humidity, minimum, maximum, and mean temperature, except rainfall, which showed a positive correlation. In the second analysis, the scatter plot showed that the rainfall had a positive correlation with malaria cases, and the rest of the climatic factors, such as temperature and humidity, had negative correlations of varying degrees. Out of the total 61 years studied, in 29 years, malaria cases increased more than 1000 square root counts when the minimum temperature was at 18–19 °C; counts also increased over a period of 33 years when the maximum temperature was 30–31 °C, over 37 years when the mean temperature was 24–25 °C, over 20 years when the rainfall was in the range of 100–120, and over a period of 29 years when the relative humidity was at 55–65%. While the rainfall showed a strong positive correlation with the annual incidence of malaria cases, the temperature and relative humidity showed negative correlations of various degrees. The increasing temperature may push the boundaries of malaria towards higher altitude and northern sub-tropical areas from the southern peninsular region. Although scanty rainfall reduces the transmission, increases in the same would increase the malaria incidence in India. Full article

PAVON has developed a malaria microscopy competency training scheme to augment competency in malaria microscopy. Here, data accrued from training activities between 2020 and 2023 in Botswana are presented. Three trainings were done for 37 central and peripheral level technicians for a two-week period. The scheme consisted of basic theory on Plasmodium parasites, malaria epidemiology and diagnosis. The practicals focused on standard slide preparation, staining, parasite detection, speciation and counting. Scores were assessed by the Wilcoxon signed rank test. Participants who excelled joined the WHO External Competency Assessment for Malaria Microscopy (ECAMM). The median competency scores for the three trainings were detection: 100 (IQR = 94–100), 100 (IQR = 94–100) and 92 (IQR = 92–100), respectively, from pre-test scores of 40 (IQR = 27–54), 44 (IQR = 32–52) and 20 (IQR = 10–40) (z = 2.937, p < 0.003, z = 3.110, p = 0.002 and (z = 2.251, p = 0.024), respectively. Speciation: 93 (IQR = 86–96), 81 (IQR = 73–96) and 88, (IQR = 88–100) from pre-test scores of 50 (IQR = 30–50), 36 (IQR = 20–45) and 17 (IQR = 17–50) (z = 2.936, p < 0.003, z = 3.152, p = 0.002 and z = 3.237, p = 0.001). The competency scores achieved in the ECAMM were 98/98 and 97/98 for sensitivity and specificity pre- and post-tests detection. The training was effective in raising the competency skills of participants and is open to NMPs (National Malaria Programs) for critical capacity building. Full article

Objective: Understanding the epidemiological features of malaria is a key step to monitoring and quantifying the impact of the current control efforts to inform future ones. This study establishes the prevalence and frequency of malaria in a forest–savannah ecozone for 5 consecutive years in Cameroon. Methods: A retrospective study was conducted in 3 health centers of Makenene from 2016 to 2020, a period covering the second long-lasting insecticide net mass distribution campaign. Malaria infectious records were reviewed from laboratory registers. The difference in exposure to malaria was estimated using a regression logistic model. Results: A total of 13525 patients underwent malaria diagnostic tests, with a general malaria prevalence of 65.3%. A greater prevalence of malaria was observed in males (68.39%) compared to females (63.14%). The frequency of consultations in health centers was dominated by females, with a gender ratio (M/F) of 0.66. Annual trends in malaria prevalence slightly varied from 2016 to 2020, exceeding 60%: 65.2% in 2016; 66.7% in 2017, 68.1% in 2018, 63.2% in 2019, and 65.3% in 2020, with a significant seasonal variation (p < 0.0001). The highest malaria prevalence was observed during the short rainy season, no matter the year. Among positive cases, the most represented age groups were 6–15 (p < 0.0001), followed by those under 5, while the age group >25 years was the least represented. Conclusion: Close monitoring and additional intervention measures for malaria control are needed, as are more studies on vector bionomics and transmission patterns. Full article

This study evaluated the impact of combining house screens with long-lasting insecticidal nets (LLINs) on mosquito host-seeking, resting, and biting behavior. Intervention houses received house screens and LLINs, while control houses received only LLINs. Centre for Disease Control light traps, pyrethrum spray collections and human landing catches were used to assess the densities of indoor and outdoor host-seeking, indoor resting, and biting behavior of malaria vectors in 15 sentinel houses per study arm per sampling method. The protective efficacy of screens and LLINs was estimated through entomological inoculation rates (EIRs). There were 68% fewer indoor host-seeking Anopheles funestus (RR = 0.32, 95% CI 0.20–0.51, p < 0.05) and 63% fewer An. arabiensis (RR = 0.37, 95% CI 0.22–0.61, p < 0.05) in screened houses than unscreened houses. There was a significantly higher indoor biting rate for unscreened houses (6.75 bites/person/h [b/p/h]) than for screened houses (0 b/p/h) (χ² = 6.67, df = 1, p < 0.05). The estimated indoor EIR in unscreened houses was 2.91 infectious bites/person/six months, higher than that in screened houses (1.88 infectious bites/person/six months). Closing eaves and screening doors and windows has the potential to reduce indoor densities of malaria vectors and malaria transmission. Full article

Malaria remains the leading cause of morbidity and mortality in Chad. The World Health Organization (WHO) has recommended that endemic countries stratify malaria to guide interventions. Thus, the Republic of Chad has initiated a stratification process based on malaria incidence with the aim of defining transmission risk and proposing interventions. We collected routine malaria data from health facilities from 2017–2021, the national survey on malaria indicators, the entomological data of NMCP operational research, the demographic and health surveys, and remote sensing of environmental data. Stratification was based on the adjusted incidence of malaria to guide interventions. The adjusted incidence of malaria was, on average, 374 cases per 1000 people in the country. However, it varied according to health districts. Health districts were stratified into very low malaria incidence (n = 25), low malaria incidence (n = 20), moderate malaria incidence (n = 46) and high malaria incidence (n = 38). Micro-stratification in health districts with very low incidence was carried out to identify districts with incidence <10 cases per 1000 person with a view to a malaria pre-elimination programme. Appropriate malaria control interventions were proposed based on the strata identified. Stratification enables the country to target interventions to accelerate the reduction of the burden caused by malaria with a pre-elimination goal. Full article

Malaria has been and remains a significant challenge in Africa and other endemic settings. Roughly, 95% of global morbidity and mortality due to malaria occurs within African populations and affects millions of individuals, especially those living in sub-Saharan countries, predominantly due to disease complications. Cultural factors such as unawareness of and disinterest in using recommended preventive tools and combating the primary host (i.e., the female Anopheles mosquito) play a significant role. This host transmits the malaria-causing Plasmodium parasite by biting an infected individual and spreading it to humans. The current overview focuses on the molecular markers associated with antimalarial drug resistance in Plasmodium falciparum (P. falciparum) in Rwanda, considered an exemplar of sub-Saharan countries where malaria is prevalent and effective policies on the development of malaria treatment, approved recently by WHO in 2025, have been adopted. The prevalence of mutations in key resistance genes, including pfcrt, pfmdr1, and pfdhfr/pfdhps, are linked to resistance against common antimalarial drugs such as chloroquine and sulfadoxine-pyrimethamine (SP). In addition, the Plasmodium falciparum kelch13 (pfk13) gene is linked to resistance against artemisinin, as its mutations can cause delayed parasite clearance and treatment failure. Despite changes in therapeutic use policies owing to high prevalence of variant alleles, which reduce the drug’s efficacy resistance to SP, the gene persists in Rwanda. Malaria parasites are becoming more resistant to chloroquine, leading to diminished effectiveness and slower recovery or treatment failure. Surveillance data reported from several studies provide crucial insights into the evolving trends of resistance markers and are vital for guiding treatment protocols and informing therapeutic use policy decisions. It is important that we continue to maintain and develop the effectiveness of malaria prevention strategies and treatments, due to the multiple types of resistance found in the population. Full article

Resistance to current antimalarial drugs is steadily increasing, and new drugs are required. Drug efficacy trials remain the gold standard to assess the effectiveness of a given drug. The World Health Organization (WHO)’s recommendation for the optimal duration of follow-up for assessing antimalarial efficacy is a minimum of 28 days. However, assessing antimalarial drug efficacy in highly endemic regions can be challenging due to the potential risks of acquiring a new infection in the follow-up period, and thus, it may underestimate the efficacy of the given drugs. A new treatment should be introduced if treatment failure rates exceed 10%. Overestimation occurs as a result of retaining a drug with a clinical efficacy of less than 90% with increases in morbidity and mortality, while underestimation may occur due to a misclassification of new infections as treatment failures with tremendous clinical and economic implications. Therefore, molecular genotyping is necessary to distinguish true new infections from treatment failures to ensure accuracy in determining antimalarial efficacy. There are three genetic markers that are commonly used in antimalarial efficiency trials to discriminate between treatment failures and new infections. These include merozoite surface protein 1 (msp-1), merozoite surface protein 2 (msp-2), and glutamate-rich protein (glurp). The genotyping of P. falciparum by nested polymerase chain reaction (n-PCR) targeting these markers is discussed with the inherent limitations and uncertainties associated with the PCR technique and limitations enforced by the parasite’s biology itself. Full article