Lusaka University, South Africa
Title: Prevalence of rheumatic heart disease in Zambian school children
Introduction: The large global burden of rheumatic heart disease (RHD) has come to light in recent years following robust epidemiologic studies. As an operational research component of a broad program aimed at primary and secondary prevention of RHD, we sought to determine the current prevalence of RHD in the country’s capital, Lusaka, using a modern imaging-based screening methodology. In addition, we wished to evaluate the practicality of training local radiographers in echocardiography screening methods. Methods: Echocardiography was conducted on a random sample of students in 15 schools utilizing a previously validated, abbreviated screening protocol. Through a task-shifting scheme, and in the spirit of capacity-building to enhance local diagnostic and research skills, general radiographers based at Lusaka University Teaching Hospital (UTH) were newly trained to use portable echocardiography devices. Students deemed as screen-positive were referred for comprehensive echocardiography and clinical examination at UTH. Cardiac abnormalities were classified according to standard World Heart Federation criteria. Results: Of 1,102 students that were consented and screened, 53 students were referred for confirmatory echocardiography. Of those, three students had definite RHD, ten had borderline RHD, and 29 were normal. Eleven students were lost to follow-up. The rates of definite, borderline, and total RHD were 2.7 per 1,000, 9.1 per 1,000, and 11.8 per 1,000, respectively. Anterior mitral valve leaflet thickening and chordal thickening were the most common morphological defects. The pairwise kappa test showed good agreement between the local radiographers and an echocardiographer quality assurance specialist. Conclusion: The prevalence of asymptomatic RHD in urban communities in Zambia is on par with that reported in other sub-Saharan African countries. Task-shifting local radiographers to conduct echocardiography was feasible. The results of this study will be used to inform ongoing efforts in Zambia to control and eventually eliminate RHD.