A snowball approach for screening of asymptomatic Rheumatic Heart Disease among school age children in Ethiopia: A comparative cross-sectional study

Abstract Background Rheumatic heart disease (RHD) is a common complication of acute rheumatic fever (ARF). ARF and RHD are the leading causes of cardiovascular morbidity and mortality. Early detection and structured prevention programs can halt the devastating effects of RHD. The study aimed to determine the overall prevalence of asymptomatic RHD and asses the case detection rates between random screening and snow ball approaches at selected schools in Addis Ababa, Ethiopia. Methods A community based, comparative, cross-sectional study was conducted at five elementary schools in Addis Ababa. Two groups of study population were identified as positive contact-known RHD patient in their class and negative contact-no known contact in their class. RHD screening was done using World heart federation 2012 echocardiographic criteria (as borderline and definitive RHD) by Lumify handheld device. Data was summarized using frequencies with percentages and median with interquartile range. Multivariable binary logistic regression model was run and adjusted odds ratio (AOR) was used to measure the strength. Results A total of 265 children (positive-108 and negative-157 contact) were screened. The median age of the participants was 11 years. The overall prevalence of asymptomatic RHD was 4.9%. The stratified prevalence among children with negative contact history-3/157 (1.9%) and positive contacts was 10/108 (9.3%). Out of the 10 cases, 2 students had mild mitral regurgitation. After adjusting for age and sex, the odds of developing asymptomatic RHD among participants with positive contact history was 5.67 times than participants with negative contact history (AOR= 5.67, 95% CI= 1.40, 22.98, p-value=0.015). Conclusion The prevalence of asymptomatic RHD was higher among children with positive contact history. The majority of these children were diagnosed with definitive RHD as compared to those with negative contact history. Screening using a snowball technique gives us a superior yield which needs further study with larger sample. Key messages RHD is the leading cause of morbidity and mortality in the developing countries. Early detection of asymptomatic RHD can help prevent progression of the disease. Screening of school children helps detect RHD early though costly and unreachable. Integration of snowball approach to trace contacts of RHD patients will minimize cost and improves detection rate.