Malaria Journal最新文献

Background: The rotational use of insecticides with diverse modes of action in indoor residual spraying (IRS) is pivotal for enhancing malaria vector control and addressing insecticide resistance. A key factor in national malaria vector control/elimination programmes is the rate at which these insecticides decay. VECTRON™ T500, with broflanilide as its active ingredient, is a recently developed candidate insecticide formulation which has shown promising results in certain phase II experimental hut trials. However, its residual efficacy across different settings has not been thoroughly investigated. This study evaluated the efficacy of VECTRON™ T500 on various wall surfaces (mud, dung, paint, and cement) and assessed its decay rates over time in Ethiopia.

Methods: Insectary-reared Anopheles arabiensis Sekoru strain mosquitoes were used to evaluate the residual efficacy of VECTRON™ T500. Female mosquitoes, aged three to five days were used for the bioassays. Seven 'tukul' type test huts, each hut with a distinct wall type (mud, dung, painted, and cemented) were used for the study. Three huts received VECTRON™ T500; three huts were sprayed with Actellic 300CS, and one hut served as a negative control (sprayed with water only).

Results: VECTRON™ T500 induced over 80% mortality across all wall surface types throughout the entire nine-month study period. In contrast, Actellic^® 300CS achieved over 80% mortality for six months, except on dung wall surfaces, after which its efficacy declined sharply below 80%.

Conclusion: Overall, the mortality rates achieved with VECTRON™ T500 extended up to nine months across all treated wall surface types, outperforming Actellic^® 300CS. This could make VECTRON™ T500 a promising candidate insecticide formulation for use in IRS in malaria-endemic countries such as Ethiopia.

Background: Burji special Woreda is one of the malaria endemic areas in Southern Ethiopia. The objective of this study was to determine the prevalence of malaria and associated factors among febrile cases in Burji special Woreda.

Methods: Institutional based cross-sectional study conducted from November 2022 to January 2023. The trend of malaria prevalence was determined based on five years malaria retrospective data (2018-2022). Blood samples were collected from 317 suspected febrile cases to determine the prevalence of malaria in the study area. Thin and thick blood smears were prepared, stained with 10% Giemsa and examined under light microscope. The data on socio-demographic and other determinant factors were collected by interviewers administered pre-tested questionnaire for suspected febrile cases. Bivariate and multivariable logistic regression analysis were done using SPSS software version 20.

Results: Among febrile cases, 22.4% (71/317) were positive for malaria. Being male (P-value = 0.026), living in grass thatched house (P-value = 0.044), availability of mosquito breeding site around residents (p-value = 0.044) and not providing IRS regularly (p-value = 0.008) were significantly associated with Plasmodium infection. Based on five years retrospective data (2018-2022), the prevalence of malaria was 27.2% in the study area. The prevalence of malaria showed fluctuating trend between 2018 and 2022 in the study area. Malaria is still prevalent in Burji special Woreda and remains the major public health problems in study area. Interventions against malaria have to be strengthened in order to reduce the burden of malaria in Burji Special Woreda. Furthermore, continuous research on the magnitude of malaria and its associated factors is needed to eliminate the disease from the study area.

Background: Rwanda has made significant strides in malaria control. This study reviews malaria epidemiology and control strategies in Rwanda from 2018 to 2023, documenting their impact, persistent gaps and emerging challenges.

Methods: Data on Rwanda's malaria context from 2018 to 2023 were obtained through a literature review of peer-reviewed articles and grey literature, including annual reports from the malaria programmes, partners, the African Union, and the World Health Organization (WHO). Specific keywords used for the search included "malaria", "Rwanda", "case management", "control", "treatment", and "prevention". Moreover, epidemiological data for this period was extracted from the Health Management Information System (HMIS). Data analysis was done using R & R-Studio, ANOVA to assess the statistical significance (P < 0.05) of observed trends and T-test to compare the focal and blanket IRS techniques.

Results/discussion: Between 2018 and 2023, all malaria indicators showed improvement. Malaria incidence dropped from 345 to 40 cases per 1000 persons (P = 0.00292), the severe malaria rate decreased from 112 to 10/100,000 persons (P = 0.018), and the mortality rate fell from 2.72 to 0.258 deaths /100,000 persons (P = 0.00617). Among children under 5 years of age, incidence decreased significantly from 331 to 52/1,000 persons (P = 0.00123), the severe malaria rate dropped from 214 to 29/100,000 persons (P = 0.00399), and mortality declined from 5 to 0.453/100,000 persons (P = 0.00504). Over the same period, key malaria interventions expanded. The proportion of cases treated by CHWs increased significantly, improving access to early diagnosis and treatment (from 13 to 59%), and the new generations of ITNs (PBO and dual-active ingredient nets) were deployed in 9 districts. Since 2019, a blanket spraying technique has been adopted in 12 IRS districts replacing the focal spraying technique contributing to the significant decrease of malaria incidence from 2019 to 2023 (P = 0.0025). However, new challenges have emerged, including the rise of the K13 R561H mutation associated with artemisinin resistance, the spread of insecticide resistance, and limited intervention coverage due to resource constraints.

Conclusion: To sustain the progress achieved, it is essential to intensify malaria control efforts, foster compliance with intervention strategies, enhance surveillance systems for timely and effective responses, and secure long-term funding to sustain these measures.

Background: Asymptomatic malaria parasitemia patients constitute an effective transmission pool for malaria infection in the community. However, less attention has been given to malaria control and elimination strategies. Therefore, to achieve a malaria elimination strategy, investigating the magnitude of asymptomatic malaria in different settings in Ethiopia is crucial. However, there is not enough information on the prevalence of asymptomatic malaria infection and associated risk factors in the Bench Sheko Zone, southwest Ethiopia. This study, therefore, aimed to provide information and help achieve sustainable malaria elimination.

Methods: A community-based cross-sectional study was conducted from February to April 2019 in Mizan-Aman town, southwest Ethiopia. A semi-structured questionnaire was used to collect sociodemographic information. Plasmodium species were screened using microscopy and rapid diagnostic test (RDT). HemoCue was used to measure haemoglobin levels. Statistical Package for the Social Sciences (SPSS) version 20.0 was used for descriptive and logistic regression statistics to risk factors. A P-value of 0.05 was used as a cutoff-value for significance.

Results: A total of 353 malaria-like symptom free participants were enrolled in this study. 17 seventeen (4.8%, 95% Confidence interval = 2.57, 7.03) asymptomatic malaria cases were revealed; among these, 12 (70.58%) (95% CI = 65.75, 75.25) were due to Plasmodium vivax and 5 (29.41%) (95% CI = 24.74, 34.25) were due to Plasmodium falciparum. Asymptomatic malaria was significantly associated with the presence of mosquito breeding sites [Adjusted odd ratio (AOR) = 6.06 (1.76-20.82)], insecticide-treated nets (ITN) use [AOR = 3.51 (0.97-12.68)], and indoor residual spraying (IRS) [AOR = 3.95 (1.26-12.37)]. Mild anaemia was found in 20% (3/15) of the asymptomatic malaria patients. Additionally, there was a significant association between malaria and anaemia [OR = 5.786 (1.46-22.85)] in this study.

Conclusions: The population of the current study area will be at risk because asymptomatic malaria is present. Low coverage of the IRS, ITN, and proximity of stagnant water in residences had an impact on asymptomatic malaria. Further studies are needed on the burden of asymptomatic malaria via molecular methods, and the Bench Sheko regional health office is better able to scale-up malaria prevention and control tools.

Background: Long-lasting insecticidal nets (LLIN) and vaccines are effective malaria control tools. However, inadequate uptake has been reported in countries where both interventions are available. To maximize the impact these tools provide, it is crucial to identify populations that are not being reached and the barriers to uptake.

Methods: In a cross-sectional study conducted in April 2024 in Kanyamwa Kologi Ward in Homa Bay County, Kenya, 4,662 households in 58 randomely selected villages were visited and interviewed. The proportions of households that (1) received at least one new LLIN within the previous five months (net distribution), (2) reported all children used LLIN (net usage), (3) reported at least one child had received one dose of the RTS,S vaccine (vaccine uptake), and (4) reported all children had received four doses of the vaccine (vaccine completion) were examined. Bayesian spatial autoregression analyses were used to estimate adjusted odds ratio (aOR) and its credible intervals (CrI) to identify the association between the household-level characteristics and the four outcomes.

Results: The overall uptake proportions were 89.9% for net distribution, 84.4% for net usage, 88.2% for vaccine uptake, and 53.7% for vaccine completion. All four outcomes showed geographical heterogeneity with significant (p < 0.05) Moran's I. Households headed by adults of > 40 years had higher odds of having received a new LLIN (aOR = 2.02, 95% CrI 1.02-5.42), having one child who had received one vaccine dose (aOR = 1.83, 0.69-4.66), and having all children fully vaccinated (aOR = 2.36, 1.09-5.46), but lower odds of net usage by all children (aOR = 0.62, 0.40-0.96). Households with five or more children had higher odds of having received a new LLIN (aOR = 5.36, 2.24-27.0) but lower odds of net usage by all children (aOR = 0.24, 0.14-0.38) and having all children fully vaccinated (aOR = 0.20, 0.04-0.61). Distance to the nearest health centre was negatively associated with all outcomes. Household wealth was positively associated with all outcomes.

Conclusion: Uptake of LLIN and malaria vaccine in Homa Bay County, Kenya varied by geography and household characteristics. These findings suggest that different sets of actions should be considered to improve the coverage and compliance of these interventions in different areas.

Background: As a widely accepted field standard diagnostic tool for malaria, microscopic examination is often difficult to perform in resource-poor settings. The immunochromatographic HRP2/pLDH (Pf/Pan) Rapid Diagnostic Tests (RDTs) serve as alternatives to microscopic examination for falciparum and non-falciparum malaria in co-endemic areas by detecting the histidine-rich protein 2 (HRP2) and pan-plasmodial lactate dehydrogenase (pLDH) antigen. However, Pf/Pan RDTs do not directly quantify parasitaemia. In this study, the diagnostic performance of Pf/Pan RDT and its association with parasite density was examined.

Methods: Blood smears from patients who were screened for PRIMA Clinical Trial (Trial Registration Number: NCT03916003) conducted in East Sumba, Indonesia, and enrolled to its sub-study, ACROSS, were examined for microscopic examination and RDT using CareStart^™ Malaria HRP2/pLDH (Pf/PAN) Combo (CareStart^™ Pf/Pan RDT). Results were analysed for both diagnostic performance of RDT and its relationship with parasite density using a logistic regression model.

Results: 317 participants were included in this study and 158 (49.8%) were malaria positive by microscopy. Among all malaria-positive participants, Plasmodium falciparum infections accounted for 149 (94.3%) cases. The sensitivity and specificity of HRP2 band were 97.3% (95% CI 93.3-99.2) and 97.6% (95% CI 94.0-99.4), respectively, while that of pLDH band were 87.3% (95% CI 81.1-92.0) and 100% (95% CI 97.7-100). For each ten-fold increase in parasite density, the RDT had 12 times the odds of returning Pf/Pan-positive results (n = 126) compared to Pf-positive (n = 19) (OR: 12.1; 95% CI 5.18 to 34.8; p < 0.001).

Conclusions: CareStart^™ Pf/Pan RDT is reliable in diagnosing falciparum malaria and Pf/Pan-positive results indicate higher parasite density. Pf/Pan-positive results should alert the clinical staff of the increased risk of poor clinical outcome, and should be prioritized for microscopic examination compared to Pf-positive results.

Background: A significant portion of malaria-related deaths occur in Africa, and Uganda is an endemic region where malaria remains a public health concern. This study aimed to determine the prevalence of malaria and its associated factors among febrile children under 15 years of age at Bududa General Hospital, Eastern Uganda.

Methods: This cross-sectional study was conducted between April and June 2023. Informed consent was obtained from parents/guardians before 250 febrile children below 15 years were enrolled in this study. A structured questionnaire was administered to parents/guardians to collect sociodemographic characteristics and identify factors associated with malaria. Venous blood samples were collected from the children and screened for the presence of malaria parasitaemia using blood smear microscopy. The data collected were entered into an Excel spreadsheet and analysed using STATA version 14. Logistic regression models were used to determine the factors associated with malaria, and we considered ≤ 0.05 as the level of significance.

Results: Out of the 250 study participants, the overall prevalence of malaria was 111(44.4%). Among the children who tested positive for malaria, 98 (88.3%) had Plasmodium falciparum, 11 (9.9%) had Plasmodium malariae, and (1.8%) had Plasmodium ovale infection. The mean parasite count was 21,951 parasites/µL of blood. The highest parasite count was 154,387 parasites/µL of blood, and the lowest count was 146 parasites/µL of blood. The prevalence rates of low, moderate, and high malaria parasitaemia were 46.8%, 28.0%, and 25.2%, respectively. In the multivariate analysis, the factors associated with malaria infections were older age; 1 to 5 years (p = 0.013), 6 to 10 years (p = 0.000), 11 to 15 years (p = 0.000), secondary education (p = 0.050), and no use of insecticide-treated bed nets (p = 0.002).

Conclusion: The prevalence of malaria among febrile children in this study was high, with nearly half of the participants showing severe infections. Health education on the correct use of insecticide-treated mosquito nets should be prioritized to help control malaria.

Background: With the recent approval of the malaria vaccine by the World Health Organization, it is expected that global acceptance and subsequent uptake of the intervention can help to reduce the burden of the disease in Africa. This study adopted a proactive approach in assessing parents' acceptance of the malaria vaccine, alongside their willingness to pay for the novel public health intervention.

Methods: A national cross-sectional survey was undertaken in Nigeria using a questionnaire as the data collection instrument. The study tool was administered to parents of child-bearing age. Descriptive and inferential statistical analyses were performed using the Statistical Package for Social Sciences (SPSS) software version 25.

Results: A total of 1413 valid responses were received with male (49.5%) and female (50.5%) participants represented by similar proportions. Close to two-thirds (62.5%) of the participants were between the ages of 31 and 40 years, and 47.4% of the participants were educated up to national diploma level. More than two-thirds (69.6%) of the participants indicated that they were worried about side effects that may be associated with the malaria vaccine. A strong majority (90%) of the participants indicated that the vaccine should be administered at no cost to citizens, while 46.7% of the respondents were willing to pay for the malaria vaccination. Levels of education attained by the respondents influenced their willingness to pay for malaria vaccination. This variable also underpinned participants'  reasons for non-acceptance of the vaccine. Those who attained only primary and secondary levels of education were significantly more likely to reject the malaria vaccine because they were against vaccines in general (AOR = 6.63; 95% CI = 1.33 - 39.25; p = 0.021).

Conclusion: This study provides critical novel insights which could influence vaccination efforts aimed at reducing the burden of malaria in Nigeria, as well as similar settings.

Background: In sub-Saharan Africa, malaria remains a public health problem despite some reports of declining incidence in the period 2000-2018. Since 2019, there have been some reports of disease epidemics and resurgences in areas that had registered steep declines and unusual clinical presentations. This study aimed to describe the epidemiology, clinical spectrum, and outcomes of severe malaria in children among malaria-endemic Eastern Uganda, a region that has recently experienced disease epidemics.

Methods: This prospective study was conducted at Mbale Regional Referral Hospital, Uganda, from 08th May 2019 to August 15, 2023, as part of the Malaria Epidemiological, Pathophysiological and Intervention studies in Highly Endemic Eastern Uganda (EDCTP-TMA2016SF-1514-MEPIE Study). Children aged 60 days to 12 years who at admission tested positive for malaria and fulfilled the clinical World Health Organization criteria for surveillance of severe malaria were enrolled into the study following appropriate informed consent. Data were collected using a customized proforma on social demographic characteristics, clinical presentation, treatment, and outcomes. Laboratory analyses included complete blood counts, lactate, glucose, blood gases, electrolytes, metabolites, and coagulation markers. In addition, urinalysis using dipsticks was done. Data were analysed using STATA V15. The study had ethical and regulatory approval before data collection commenced.

Results: A total of 1,379 participants were recruited. The median age was 4 years (2 months-12 years). Most children 757/1379 (54.9%) were under 5 years, and 825/1379 (59.8%) were males. The common symptoms were fever 1368 (99.2%), poor appetite 1095 (79.5%), inability to sit upright 1051 (76.2%), vomiting 944 (68.4%) and yellow eyes 833 (60.4%). The common signs included prostration, haemoglobinuria and jaundice. Prolonged hospitalization was found in 284/1339 (21.2%) and was associated with impaired consciousness 116/166 (30.1%), P = 0.003; haemoglobinuria 514/705 (27.1%), P < 0.001 and jaundice 505/690 (26.8%) P < 0.001. The overall mortality was 40/1347 (3.0%). Children who had > 1 severity feature were at a higher risk of mortality.

Conclusion: In this prospective study of children with severe malaria in Eastern Uganda, the overall mortality was 3.0% and the more the disease clinical syndromes the higher the risk of death.

Background: Tanzania is a malaria-endemic country that relies solely on anti-malarial drugs and vector control measures, including insecticide-treated bed nets and indoor residual spraying. However, the growing resistance to these interventions threatens their effectiveness, highlighting the need for additional strategies to accelerate malaria eradication efforts. Currently, malaria vaccines have begun to roll out in endemic areas. However, hesitancy emanating from misinformation on vaccine efficacy and safety has been recorded in various parts of the world. In this context, this study investigated the knowledge and willingness of caregivers towards the malaria vaccine.

Methods: This is a health facility-based cross-sectional survey conducted from September 2022 to March 2023. In total, 293 caregivers attending Ante-Natal Clinics (ANC) in selected health facilities in Dar es Salaam were recruited. A semi-structured questionnaire was used to collect caregivers' demographic information, knowledge of malaria, knowledge of malaria vaccines and willingness to receive malaria vaccines.

Results: The respondents were predominantly women (97.3%) aged 18 to 52 years. Overall, 87.4% had knowledge of malaria disease, while 14% did not know how malaria is transmitted. Most respondents (86.3%) knew about malaria prevention/control methods. However, only 14.7% of the recruited caregivers were aware of the malaria vaccine. Of those exposed to vaccine messages, 67.4% were aware that the vaccine was for children under 5 years of age, while 53.5% knew that the vaccine was for pregnant women. Despite their low exposure, most respondents (92.8%) were willing to receive the malaria vaccine for their children under five years.

Conclusion: Malaria knowledge and willingness to vaccinate against malaria was high among Tanzanian caregivers despite the low awareness of malaria vaccines. This suggests the need for targeted information, education and communication strategies (IECs) for communities to curb misconceptions and complement their high willingness to accept the malaria vaccine in Tanzania.