Echocardiographic screening of 4107 Nigerian school children for rheumatic heart disease

OBJECTIF: Le depistage echocardiographique de la cardiopathie rhumatismale (CR) en Afrique a revele des taux de prevalence compris entre 0,5 et 7,4%. Il n'existe pas de grande etude recente de population au Nigeria. L'objectif de l’etude etait de determiner la prevalence de la CR dans un grand echantillon d’ecoliers nigerians. METHODES: A l'aide d'une echocardiographie et d'une auscultation trans-thoraciques portables, des ecoliers âges de 5 a 16 ans de Lagos, au Nigeria, ont ete soumis a un depistage de la CR. Le diagnostic reposait sur les criteres echocardiographiques de la Federation Mondiale du Cœur de 2012. RESULTATS: Les 4.107 enfants testes avaient un âge moyen de 11,3 ans (DS = 2,6) et 2.206 (53,7%) etaient de sexe feminin. Il y avait des echocardiogrammes anormaux chez 38 enfants, dont 11 (0,27%) presentaient une CR, y compris deux cas de CR bien definie, donnant une prevalence de 2,7/1000 [2,9/1000 dans les zones periurbaines, 2,4/1000 dans les zones urbaines). L’echocardiographie a detecte une CR 10 fois mieux que l'auscultation [echocardiographie 11 (0,27%) contre auscultation 1 (0,02%); p = 0,003]. Les 27 enfants restants dont les echocardiogrammes etaient anormaux avaient une cardiopathie congenitale (CHD), ce qui donnait une prevalence de 6,6/1.000 pour les cardiopathies congenitales, donnant une prevalence de 6,6/1000, un rendement superieur a celui de la CR. METHODS: Using portable transthoracic echocardiography and auscultation, school children aged 5 years to 16 years in Lagos, Nigeria were screened for RHD. Diagnosis was based on the 2012 World Heart Federation echocardiographic criteria. RESULTS: The 4107 children screened had mean age of 11.3 years (SD = 2.6) and 2206 (53.7%) were females. There were 38 children with abnormal echocardiograms, of which 11 (0.27%) showed RHD including two cases of definite RHD giving a prevalence of 2.7/1000 [2.9/1000 in the peri-urban, 2.4/1000 in the urban area). Echocardiography detected RHD 10 times better than auscultation [echocardiography 11 (0.27%) vs. auscultation 1 (0.02%); P = 0.003]. The remaining 27 children with abnormal echocardiograms had congenital heart defects (CHD) giving a prevalence of 6.6/1000 for CHD, a yield higher than for RHD. CONCLUSION: Prevalence of RHD among school children in Lagos, South West Nigeria is low compared to other African countries, possibly due to better access to medical care and antibiotic treatment for infections. Our data provides evidence that RHD prevalence may vary substantially within sub-Saharan Africa, necessitating targeted population-based sampling to better understand disease burden and distribution. Further work is needed to compare within- and between-country RHD prevalence as a basis for programme planning and control efforts.