Prevalence and risk factors for Subclinical Rheumatic Heart Disease among primary school children in Dar es Salaam, Tanzania: a community based cross-sectional study

Parvina Titus Kazahura,Edward Kija,Mazen Albaghdadi,Pedro Pallangyo,Mohamed Janabi,Theophylly L Mushi,Naizihijwa Majani,Rodrick Kisenge

doi:10.1186/s12872-021-02377-9

Abstract

BackgroundRheumatic heart disease (RHD) is the most common acquired heart disease occurring in children and adolescents. RHD is associated with significant morbidity and mortality particularly in low and middle- income countries (LMICs) where the burden is estimated to be higher compared to high income countries. Subclinical RHD is the presence of valvular lesion diagnosed by echocardiography in a person with no clinical manifestation of RHD. This study aimed at determining the prevalence, types and factors associated with subclinical RHD among primary school children in Dar Es Salaam, Tanzania.MethodsA descriptive community-based cross-sectional study was conducted in primary school children from February to May 2019. A standardized structured questionnaire was used to collect demographic characteristics, history of upper respiratory tract infections (URTIs), anthropometric measurements, and chest auscultation findings. Moreover echocardiographic screening was done to all children recruited into the study. World Heart Federation echocardiographic classification was used to define the types and prevalence of subclinical RHD.ResultsA total of 949 primary school children were enrolled with females being predominant (57.1%). The prevalence of subclinical RHD was 34 per 1000. All the participants had mitral valve disease only whereby 17 had definite disease and 15 had a borderline disease. The associated factors for subclinical RHD were older age of more than 9 years (OR 10.8, 95% CI 1.4–82.2, P = 0.02) having three or more episodes of URTI in previous six months (OR 21, 95% CI 9.6–46, P = 0.00) and poor hygiene (OR 3, 95% CI 1.3–6.8, P = 0.009).ConclusionSubclinical RHD as detected by echocardiographic screening is prevalent in primary school children, uniformly affects the mitral valve, and is associated with potentially modifiable risk factors. Children with a history of more than three episodes of URTI in six months represents a high-risk population that should be targeted for RHD screening.

Highlights

Rheumatic heart disease (RHD) is the most common acquired heart disease occurring in children and adolescents
We found that subclinical RHD as detected by echocardiographic screening is not uncommon in primary school children in Dar es salaam, uniformly affects the mitral valve, and is associated with potentially modifiable risk factors
Subclinical RHD detected by echocardiography is common in primary school children in Tanzania

Summary

Introduction

Rheumatic heart disease (RHD) is the most common acquired heart disease occurring in children and adolescents. Subclinical RHD is the presence of valvular lesion diagnosed by echocardiography in a person with no clinical manifestation of RHD. Rheumatic fever (RF) is a multi-system, post infectious inflammatory disease, which presents as a delayed sequela to Group A streptococcal (GAS) pharyngitis. In developing countries it remains a major health concern. After a patient has had RF, there is often a prolonged period of subclinical disease characterized by changes in valvular morphology and function [4]. Subclinical RHD is a term used to describe the presence of morphological and functional valvular lesions detected by echocardiography but with no corresponding heart murmur [7]. The latent period of subclinical RHD provides a window of opportunity for screening, initiation of secondary prophylaxis, and referral for valvular intervention when appropriate

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