A Surveillance Study of the Serotypes of Streptococci in the Throat and Skin Lesions in Acute Rheumatic Fever and Rheumatic Heart Disease Patients and their Families

Abstract

Abstract Objectives: The objectives of this study were to determine the colonization of the throat and skin among patients of rheumatic heart disease (RHD) or acute rheumatic fever (ARF) and to elucidate the different Lancefield serotypes of streptococci (Group A, Group C, and Group G) among them. Methods: The prospective observational surveillance study was conducted from November 2016 to March 2018 among 161 enrolled family members belonging to 30 families with one of their patients being diagnosed with RHD/ARF. The outcome measures were period prevalence of serotypes of streptococci, streptococcal colonization of throat and skin lesions, and association of age and antibody titers with RHD/ARF. Results: Out of 30 families enrolled in our study, positive throat (n = 18)/skin (n = 1) cultures were found in 7 families (n = 19). The cultures were positive only for Group A streptococci (GAS), while none of the samples showed positivity for Group C or G serotypes. Overall period prevalence for our study period was 3.2%. Among the 18 members positive for GAS throat culture, 13 (72.2%) belonged to the age group <15 years (P < 0.025). The positive cultures in the throat sample were more in the ARF families than RHD families (P < 0.001). There was no association of culture positivity with antibody titer (P > 0.05). Conclusion: In conclusion, we found only GAS colonization in significantly higher proportion among the family members of cases of ARF in comparison to RHD. Rather there was no case of Group C and G streptococci colonization in cases or family members of RHD/ARF.