Abstract 19428: Evaluating the Risk of Rheumatic Heart Disease Among Family Members of Children Identified With Latent RHD in School-based Echocardiographic Screening

Abstract

Background: Poorly understood genetic susceptibility factors influence who develops acute rheumatic fever (ARF) and who develops the long-term complication, rheumatic heart disease (RHD). Risk of RHD in family members - and thus the need for screening of first degree relatives - once an index case has been identified, is not known. Methods: Sixty RHD positive children (30 borderline 30 definite RHD) and 67 age & gender matched controls were recruited from previous school-based echocardiographic screening. All first-degree relatives ≥ 5 years were invited for echocardiographic screening (2012 World Heart Federation Criteria). Absent family members were recorded with reason for absence including death. Continuous variables were compared using 2-tailed independent samples t-test, categorical variables by Fisher’s Exact Test, and relative risk was used to compare cases and controls. Results: A total of 454/733 (62%) family members were screened (106 mothers, 48 fathers & 300 siblings). Definite RHD was more common in childhood siblings of cases than controls (p=0.05), and children with RHD were 4.5 times as likely to have a sibling with RHD compared to controls. Mothers had more RHD than fathers without regard to child’s screening status. Conclusions: Siblings of children identified with latent RHD are at greater risk of having RHD and screening of these children should be considered. While no adult RHD screening data exists from sub-Saharan Africa, this study suggests that the prevalence of occult RHD in adult women is quite high (9.4%). Genotyping studies are needed to fully understand individual and family susceptibility to RHD.