Malaria Journal最新文献

Background: Anopheles funestus group and Anopheles gambiae complexes are among the most efficient malaria vectors in Africa, thriving in a variety of environments and well adapted to develop in semi-permanent and permanent water bodies. This study investigated the spatial distribution of the An. funestus group and their contribution to malaria transmission in Burkina Faso.

Methods: An entomological survey was conducted from October to December 2022 across 67 sites within the ecological zones of Burkina Faso (once a month); An. funestus was detected in 22 of these sites. Mosquitoes were collected using pyrethrum spray catches (PSC) and identified at the species complex level using morphological keys. A polymerase chain reaction (PCR) was performed for species identification among An. funestus group, blood meal sources and Plasmodium falciparum infection.

Results: A total of 617 members of the An. funestus group (45 males and 572 females) were collected across eight regions of Burkina Faso. Anopheles funestus s.s. was the most prevalent specie identified with a frequency of up to 95% (589/617). Most An. funestus s.s. were found in the Hauts-Bassins and the Sud-Ouest regions with 30% (177/589) and 55% (329/589), respectively. Hybrids between An. rivulorum and An. rivulorum-like were identified at a frequency of 3.57% (22/617). Additionally, results showed a high prevalence of zoophilic behaviour (64.3% of the blood source) in An. funestus. Plasmodium falciparum infection was detected in 5.76% (33/572) of the An. funestus s.l. populations with a frequency of 5.6% (32/572) and 0.174% (1/572) in An. funestus s.s. and An. rivulorum-like, respectively.

Conclusions: This study updates the distribution of the An. funestus group and its potential role in malaria transmission in Burkina Faso. It emphasizes the need to strengthen malaria vector surveillance and highlights the importance of incorporating An. funestus in developing innovative vector control interventions.

Background: Malaria remains a leading cause of morbidity and mortality among children under five in Nigeria, with pronounced subnational disparities. This study analyzed the temporal and spatial inequalities in malaria incidence and mortality among children aged 0-4 years across Nigeria's 36 states and the Federal Capital Territory from 2010 to 2019.

Methods: Estimates from the Institute for Health Metrics and Evaluation (IHME) were analyzed using the WHO Health Equity Assessment Toolkit (HEAT). Subnational inequalities were quantified using five metrics: coefficient of variation (COV), difference (D), ratio (R), population-attributable risk (PAR), and population-attributable fraction (PAF).

Results: From 2010 to 2019, national malaria incidence declined from 103 to 74.5 cases (27.7% reduction), while mortality fell from 477.3 to 237.6 deaths per 100,000 (50.2% reduction). However, progress was uneven. Northern states such as Zamfara, Kano, and Katsina had the highest baseline burden in 2010 (incidence > 150 per 1000; mortality > 700 per 100,000) and, despite declines, remained among the most affected in 2019. Southern states including Lagos, Delta, and Anambra consistently recorded lower burdens (incidence < 60 per 1000; mortality < 300 per 100,000). Subnational inequality narrowed over time, with incidence COV peaking at 46.3% in 2013 before falling to 28.1% in 2019, and mortality COV declining from a 2013 peak of 42.9% to 22.3% in 2019.

Conclusion: Nigeria's malaria incidence and mortality among under-five children have decreased, but subnational disparities persist, particularly in northern states, although a reduction in D and R values indicates modest progress in equity, necessitating geographically targeted interventions.

Background: Mathematical modeling can be a useful approach to explore potential impact of malaria interventions and thereby inform resource prioritization decisions. However, expertise for applied modeling for public health decision-making is limited in malaria-endemic countries. A 4-month faculty enrichment program (FEP) in applied malaria modeling was implemented at Northwestern University, USA, in 2022 and 2023 with components including technical skills development, communication skills development, and domain knowledge on malaria epidemiology.

Methods: Two cohorts of FEP participants and instructors were interviewed at baseline, midline, and endline to understand their expectations, experiences, and challenges with the program.

Results: Participants valued their growth in technical expertise, research skills, and communication ability, as well as clear opportunities for knowledge transfer at their home institutions. Participants reported challenges with cross-disciplinary learning, balancing program components, and adapting to new teaching and learning styles. Instructors adapted program structures and teaching approaches to adjust to participant needs and reported strengthening of their own technical capacity.

Conclusion: Training programs for technical skill development must be informed by the needs and priorities of prospective participants and include continuous feedback mechanisms to respond to emerging needs. Multi-pronged approaches increase long-term program value to participants and help establish pathways for knowledge transfer.

Background: Malaria remains a major public health challenge, particularly in sub-Saharan Africa, which accounted for approximately 95% of global malaria cases and 96% of malaria deaths in 2022. This study examined the prevalence of malaria among children aged 6-59 months in Ghana and assessed the influence of household characteristics and water, sanitation, and hygiene (WASH) factors on malaria prevalence.

Methods: We analyzed data from the 2022 Ghana Demographic and Health Survey (GDHS), using a weighted sample of 3255 households with children aged 6-59 months. Malaria testing was performed with rapid diagnostic tests (RDTs). Descriptive statistics, chi-square tests, and multivariate logistic regression models were used to identify factors associated with malaria prevalence.

Results: The prevalence of malaria among children aged 6-59 months was 3.7%. Insecticide-treated net (ITN) ownership was high (78.9%), but only 51.5% of children slept under ITNs. Approximately 41.5% of children were anaemic. In multivariate analysis, children in households headed by persons aged 40-49 years (aOR = 0.22; CI 0.08-0.62) and 50-59 years (aOR = 0.18; CI 0.04-0.72) had lower odds of malaria compared to those in households headed by persons aged 70 + . Children from wealthier households had significantly lower odds of malaria (aOR = 0.15; CI 0.03-0.71). Unexpectedly, children who did not sleep under ITNs had lower odds of malaria (aOR = 0.52; CI 0.30-0.92) compared to those who did. Anaemic children had more than twice the odds of malaria (aOR = 2.03; CI 1.36-3.04). Drinking untreated water (aOR = 0.47; Cl 0.26-0.47) and improved sanitation (aOR = 0.59; Cl 0.39-0.90) were associated with lower malaria risk, whereas having toilets located outside (aOR = 16.64; CI 2.06-134.57) the dwelling was associated with higher odds of malaria.

Conclusion: These findings emphasise the need for targeted interventions in households with lower wealth and inadequate sanitation, alongside enhanced ITN distribution programs and sustainable WASH improvements to reduce malaria prevalence in children.

Background: Malaria is a major global health burden that accounts for the morbidity and mortality of the population. The 2020 World Health Organization reports showed that malaria affects around 241 million people worldwide. Therefore, the study evaluated the pooled prevalence of Glucose-6-phosphate dehydrogenase deficiency (G6PDd) in patients with malaria.

Methods: Various electronic databases were used to search all relevant studies through consideration of all study periods. The data were collected from PubMed, Cochrane, and Hinari, databases. Additionally, the Google Scholar search engine was used to screen research articles in the study area. The pooled prevalence of G6PDd was determined using a random effects model. On the other hand, sensitivity analysis and publication bias were performed during the meta-analysis.

Results: The overall pooled prevalence of G6PDd was 6% (0.04-0.08: 95% CI). The highest and lowest prevalence of G6PDd were 23% (0.06-0.41: 95% CI) and 1% (0.00-0.03: 95% CI) estimated at Jimma and three malaria endemic regions respectively.

Conclusions: In this study, the overall pooled prevalence of G6PDd was 6%. The prevalence of emerging mutant variants such as ChrX:154535443, ChrX:6369, ChrX:6504, and G267 + 119C/T has been detected in specific study areas. However, the majority of G6PDd cases were associated with the A376G and A376T mutant variants. The G6PDd G202A was also detected even if its distribution was low compared to these mutants.

Malaria overdiagnosis contributes to misuse of antimalarials and mistreatment of other illnesses. Although the DRC's national guidelines mandate rapid diagnostic tests (RDTs) for malaria testing and treatment, healthcare providers overreport malaria cases compared to the proportion of positive tests interpreted and recorded by an automated Deki reader and uploaded to a cloud server. Significantly higher test positivity rates (TPRs) are reported through the national Health Management Information System (HMIS) compared to the Deki reader database, especially in the dry season. Understanding the reasons behind malaria overdiagnosis and overreporting is important for providing appropriate treatment and avoiding antimalarial over-prescription. This qualitative study explores factors influencing provider nonadherence to malaria RDT results. Sixty-four semi-structured interviews were conducted with staff at 16 primary-level health facilities in Kasai Central and Haut Katanga provinces. Twelve key informant interviews with health officials and 24 focus groups with community members provided additional context. Providers and health facility supervisors were less likely to trust RDT results when they were negative than positive. To many providers, fever was synonymous with malaria and a positive RDT provided confirmation of their presumptive diagnosis while a negative RDT challenged it. To integrate the negative RDT into their existing mental model, providers explained how RDTs could return false negative results. Explanations for why RDTs may be inaccurate included that improperly treated malaria can result in a negative test, RDTs are negative early in infection, RDTs do not capture all malaria species, and the wide range in RDT accuracy. Providers and technical personnel noted financial incentives to carrying out microscopic examination rather than RDTs as per DRC's national guidelines. Guidance communicated to service providers in high-endemic, low-resource malaria settings prior to RDT availability, such as presumptive treatment of all fevers as malaria, leads providers to oppose basing treatment decisions on RDT results. Sharing data on RDT efficacy at the country level could increase confidence in RDT results, and better understanding of how RDTs work and what they measure would dispel misconceptions about false negatives. Better oversight of facility-level data, and comparisons with neighboring facilities, could improve adherence to national guidelines in the DRC.

Background: Historically malaria has been a major cause of morbidity and mortality in the Greater Mekong Sub-region. In recent years, significant progress towards malaria elimination has been made. Myanmar harbours most of the region's malaria burden, however after initial progress during peace time, the civil war and the COVID-19 pandemic have coincided with a resurgence of malaria. This observational study examines the resurgence of malaria in Eastern Myanmar and its contributory factors.

Methods and results: Malariometric and genomic data from a long-established network of malaria clinics and village health workers in eastern Karen State serving an estimated population of 350,000 were reviewed and analysed in the context of the COVID-19 pandemic and the military coup that followed. Data from 2020 and 2024 show that the number of cases of P. falciparum malaria increased 12-fold and those of P. vivax malaria increased threefold. This resurgence was greatest in the northern parts of Karen State and coincided with reduced access to timely diagnosis and treatment. This was associated with increased malaria transmission of P. falciparum (RR = 1.72, 95% CI 1.68-1.76) and P. vivax (RR = 1.82, 95% CI 1.80-1.84). Reported malaria-related deaths remained low during the study period though underreporting cannot be excluded.

Conclusion: Our study provides evidence that the disruption of services (early diagnosis and treatment) caused by the COVID-19 pandemic followed by insecurity, explains the resurgence of malaria in Karen State in Myanmar. Population movements and the clonal expansion of a specific parasite lineage were likely contributing factors. However, the decline recorded in 2024 in the number of cases and the near absence of malaria mortality showed that despite the difficulties, the malaria control system has been successful in containing the crisis. The battle for malaria control in Burma has not been lost, but the future remains uncertain.

Background: Long-lasting insecticidal nets (LLINs) are essential for malaria prevention, yet consistent use remains suboptimal. This study assessed LLIN use and associated factors in Thailand and Myanmar across diverse transmission contexts.

Methods: We analyzed cross-sectional data from 13,459 individuals attending malaria service points in three districts in Thailand and two townships in Myanmar (2017-2024). LLIN use was categorized as daily, intermittent, or non-use. Logistic regression identified factors linked to non-regular use in each country. A directed acyclic graph (DAG) illustrated hypothesized causal pathways.

Results: Among 3,062 participants in Myanmar, 16.9% reported intermittent or non-use. Higher odds were observed among individuals aged 5-14 years (aOR = 1.87, 95% CI: 1.29-2.75), 15-34 years (aOR = 3.42, 95% CI: 2.07-5.67), and ≥ 35 years (aOR = 4.42, 95% CI: 2.50-7.86), Rakhine ethnicity (aOR = 3.54, 95% CI: 2.76-4.57), residence in Paletwa (aOR = 20.9, 95% CI: 5.29-109), uncertain malaria history (aOR = 8.03, 95% CI: 3.61-18.4), and Plasmodium falciparum infection (aOR = 2.87, 95% CI: 2.02-4.06). Among 10,397 participants in Thailand, 31.2% reported intermittent or non-use. Significant factors included older age (aOR = 2.73, 95% CI: 2.07-3.62 for 15-34 years), male sex (aOR = 1.73, 95% CI: 1.56-1.91), agricultural occupation (aOR = 1.42, 95% CI: 1.04-1.95), residence in Bannang Sata (aOR = 17.9, 95% CI: 14.4-22.4) or Saba Yoi (aOR = 34.4, 95% CI: 23.3-52.3), P. falciparum (aOR = 3.61, 95% CI: 1.71-7.78), P. vivax (aOR = 2.74, 95% CI: 2.38-3.17), and lower odds with uncertain malaria history (aOR = 0.49, 95% CI: 0.35-0.68).

Conclusion: Non-regular LLIN use was common and linked to demographic, occupational, and clinical factors. Context-specific strategies are needed to improve adherence and support malaria elimination goals.

Background: Malaria-associated acute kidney injury (MAKI) represents a severe complication of malaria, increasingly documented in both Plasmodium falciparum and Plasmodium vivax infections across endemic regions.

Methods: A systematic review and metaanalysis using PubMed, EMBASE, and Cochrane CENTRAL was conducted to identify studies published between 2000 and 2024. This review evaluates the existing literature on MAKI in adult population, aiming to synthesize data on demographics, Plasmodium species, kidney involvement, dialysis need, mortality, kidney histopathology, and long-term kidney outcomes.

Results: The review included 25 studies with 2,094 MAKI patients predominantly from South Asia, especially India followed by Pakistan and Thailand. Plasmodium falciparum was the most common species implicated, though severe AKI due to P. vivax was increasingly reported. AKI definitions varied, using serum creatinine thresholds or classifications like KDIGO, RIFLE, and WHO. The incidence of MAKI ranged from 2.4 to 45.5%, rising to as high as 77% among patients with severe malaria. The pooled incidence of AKI among adults patients with malaria was 26.5% (95% CI 19.8-34.4; I² = 97%). Dialysis was required in 20-90% of cases. The mean creatinine ranged from 1.5 to over 10 mg/dL. The pooled mortality among adults MAKI patients was 19.2% (95% CI 12.9-27.7%). Mortality varied from 5 to 52%, higher in cases with delayed presentation, cerebral malaria, sepsis, need for mechanical ventilation, metabolic acidosis, and multiorgan failure. Among 95 biopsied cases, acute tubular necrosis was most common but vascular injuries like thrombotic microangiopathy and acute cortical necrosis were strongly associated with P. vivax. Long-term data were limited, but 5-20% of patients developed chronic kidney disease or kidney failure. Sub-Saharan Africa remained underrepresented despite its high malaria burden.

Conclusion: MAKI is a severe complication of malaria with regional variation in species, outcomes, and care access. Improved diagnostics, timely dialysis, and long-term nephrology follow-up are essential in endemic regions.

Background: Vector-borne diseases are still responsible for the deaths of one million people worldwide every year, particularly in African countries. Plans to combat this worldwide burden, including strategies to control vectors, are still being investigated. Among them, the behavior of chimpanzees, our closest relatives living in African forests, has been studied. In Kibale National Park in Uganda, chimpanzees ingest plants that are biologically active against Plasmodium falciparum responsible for malaria but also select tree species to build their nests. The essential oils extracted from their leaves have repellent effects on Anopheles gambiae, which are vectors of Plasmodium falciparum.

Methods: To investigate the chemodiversity of trees used by chimpanzees, essential oils (EOs) from the leaves of Vepris nobilis, Lepisanthes senegalensis, Turraeanthus africanus, and volatile extracts from the leaves of Celtis africana, which are not used for nesting by chimpanzees, were studied via gas chromatography‒mass spectrometry. The repellent, irritant and toxic activities of the compounds selected on the basis of their abundance, availability and previously studied properties were subsequently tested under laboratory conditions alone and in mixtures on female An. gambiae.

Results: Volatile compounds abundant at concentrations greater than 0.1% in the four plants were identified. We demonstrate different chemical profiles between the three EOs and the volatile extract, with molecules present in the essential oils such as β-elemene, δ-elemene, caryophyllene, α-humulene, or germacrene D. Chemical families specific to Celtis africana include aldehydes, ketones, carboxylic acids, furans, and vinylphenols. Only linalool was present in all four extracts. The mix we prepared and tested on mosquitoes, which contained α-humulene, caryophyllene, linalool and citral, is toxic and irritant to An. gambiae.

Conclusions: This study describes volatile compounds present at more than 0.1% in the leaves of four species of Ugandan trees. Certain molecules present only in species used by chimpanzees in their nests can be combined to prepare solutions with anti-mosquito properties. The outcome of this work could lead to the formulation of a repellent spray inspired by chimpanzee behavior and the environment against An. gambiae to add a means of malaria prevention.