Prevalence and factors associated with malaria gametocyte carriage among school-aged children in Masaka District, Uganda

Abstract

Background: Despite the scale-up of malaria control measures, certain populations remain prone to malaria parasitemia. Malaria among school-aged children is often underrated since most infections are asymptomatic. However, these infections are significant as they remain untreated for long periods, thus sustaining malaria transmission within communities. Malaria gametocyte carriage, which is common among school-aged children, has been associated with high rates of mosquito infectivity and so it is important to identify and treat children with gametocytes to break malaria transmission. Objective: To determine the prevalence and factors associated with malaria gametocyte carriage among school-aged children in Masaka district, Uganda. Methods: A community-based cross-sectional study was carried out among school-aged children (5-15 years) in Masaka district. The study was conducted during the COVID-19 pandemic, which led to a country lockdown that affected schools. Instead, school-aged children were identified from the community and screened for eligibility to join the study. A questionnaire was administered to all eligible children to capture information on socio-demographic characteristics, risk factors for gametocyte carriage, and the use of malaria control interventions. All study children were screened for malaria parasites and the presence of malaria gametocytes by microscopy. The proportion of school-aged children with gametocytes was used to determine the prevalence of malaria gametocyte carriage. The Poisson regression was deployed to determine the factors associated with malaria gametocyte carriage in the study population. Results: Between December 2021 and January 2022, 497 asymptomatic school-aged children were enrolled in the study. Of the 497 participants enrolled, 50(10.1%) had malaria parasites, and P.falciparum species caused the most infections. The microscopic malaria gametocyte carriage prevalence was 3.4% (17/497). Older children (10-15 years) were more likely to carry malaria gametocytes than those aged 5-9 years [58.8% versus 41.2% (p value=0.71)]. The factors significantly associated with malaria gametocyte carriage were living near ongoing bricklaying activities (APR: 6.89; 95% CI: 1.61-9.92; p-value = 0.003)¸ history of fevers in the past two weeks (APR: 4.49; 95% CI: 1.89 -10.65; p value=0.001) and staying within 0.5 to 1km to the nearest water source (0.5 to 1 km) (APR: 2.97; 95% CI: 1.04–8.46; p value= 0.042). Conclusion: The prevalence of malaria gametocyte carriage is high in this community. Older children with a history of fever in the previous two weeks and those close to water sources were more likely to carry malaria gametocytes in their blood. Recommendations: Older children and those living near water bodies/open water ditches should be prioritized for screening and treatment for malaria gametocytes to interrupt malaria transmission in Masaka district. The government should introduce more efficacious gametocidal drugs such as primaquine into routine care. Overall, the community should be prioritized for periodic malaria screening and treatment of asymptomatic school-aged children. Keywords: Asymptomatic malaria¸ Malaria gametocyte carriage¸ School-aged children.