Prevalence, Staging, and Factors Associated With Rheumatic Heart Disease Among Primary School Children, in Mwanza, Tanzania

Background Rheumatic heart disease (RHD) is a preventable acquired heart disease affecting children and adolescents. RHD is primarily prevented through the treatment of throat infections or, secondarily, through early detection and monthly treatment with appropriate penicillin to halt the progression of valvular damage caused by recurrent acute rheumatic fevers. Early detection is achieved by screening asymptomatic children for RHD using echocardiography and providing appropriate intervention based on disease stage. Objectives This study aimed to determine the prevalence, staging, and factors associated with RHD among primary school children in Mwanza, Tanzania. Methods A community-based cross-sectional study, conducted from January to May 2025, involving children aged 6–15 years from 6 urban primary schools. Participants were randomly selected after obtaining informed consent from their parents or guardians. Data collection included a standardized questionnaire for socio-demographic and clinical information, a focused physical examination, and echocardiographic screening adhering to the 2023 World Heart Federation guidelines for RHD diagnosis. Data analysis used Stata 15.0, with chi-square tests for categorical variables, Student’s t-tests for continuous variables, and multivariable logistic regression for factors with p < 0.2 from univariable analysis, considering p < 0.05 significant. Results A total of 2,280 participants were approached, and 1,325 were enrolled after meeting the inclusion criteria. The median age was 9.9 ± 2.3, with the predominance of girls by 53.7%. The RHD prevalence was 3.9% (52/1,325 cases), with 19.2% and 80.8% of cases being Stage A (subclinical) and Stage B (mild RHD), respectively; no moderate or severe cases were found. Factors significantly associated with RHD included age ≥ 8 years (OR = 2.729, p = 0.04), extended family structure (OR = 5.74, p = 0.02), self-employed main caregiver (OR = 1.92, p = 0.047), and poor oral hygiene (OR = 3.86, p = 0.03). Gender, household size, and a history of sore throat showed no significant associations. Conclusions This study highlights a significant RHD burden in Mwanza, driven by socioeconomic factors like extended families, self-employed caregivers, and poor oral hygiene, with early-stage cases detectable through echocardiography. Routine school-based screening, health education on oral hygiene, and benzathine penicillin prophylaxis are recommended to manage early RHD, alongside longitudinal studies to track progression and intervention efficacy in high-risk settings.