Sociodemographic and socioeconomic predictors of asymptomatic malaria among children and adolescents in rural Guinea: a longitudinal study
Introduction Despite substantial progress in malaria control, asymptomatic malaria infection remains an important challenge for malaria elimination efforts in sub-Saharan Africa, particularly among older children and adolescents who may sustain ongoing transmissions. However, longitudinal evidence on the sociodemographic and socioeconomic determinants of asymptomatic malaria infection in rural areas remains limited. This study investigated the predictors and seasonal dynamics of asymptomatic malaria infection (AMI) in children and adolescents in Rural Guinea. Methods We conducted a longitudinal cohort study in the rural sub-prefecture of Maferinya, Guinea, between March 2022 and February 2023. Children and adolescents aged 1–19 years were followed through repeated monthly visits covering both dry and rainy transmission seasons. Sociodemographic, socioeconomic, and parasitological data were collected using standardized questionnaires and microscopy. Mixed-effects logistic regression models with random intercepts for participants were used to identify the predictors of AMI while accounting for repeated measurements. Interaction analyses explored heterogeneity across age groups and seasons, and adjusted predicted probabilities were estimated using the final model. Results Of 300 consented participants, 297 initiated study participation. After excluding 32 participants lost to follow-up (29 children, 0 adolescents), 268 participants (159 children aged 1–9 years and 109 adolescents aged 10–19 years) completed all nine scheduled monthly visits, contributing 2,412 visit-level observations to the final analysis. The predicted probabilities of malaria infection varied across age groups and seasons, with the highest probability observed among adolescents aged 10–14 years during the rainy season (5.2%, 95% CI: 1.3–18.6) and among those aged 15–19 years during the dry season (4.2%, 95% CI: 1.0–15.5). After adjustment, participants from households headed by individuals aged 35–49 years had higher odds of malaria infection than those from households headed by younger adults aged 22–34 years (aOR: 2.39, 95% CI: 1.04–5.48). Conclusion Malaria infection among children and adolescents in rural Guinea is shaped by both seasonal transmission dynamics and household social characteristics. Older children and adolescents may represent important reservoirs of persistent transmission, highlighting the need for age-sensitive malaria surveillance and prevention strategies that extend beyond children aged under five years.