Epidemiology of infective endocarditis in Africa: a systematic review and meta-analysis

Abstract

Background: The epidemiology of infective endocarditis in Africa is inadequately characterised. We therefore aimed to comprehensively summarise the available data for the incidence, risk factors, clinical pattern, microbiology, and outcomes of infective endocarditis in Africa.

Methods: We did a systematic review and meta-analysis. We searched PubMed, Embase, African Index Medicus, and African Journals Online for all studies reporting primary data for the epidemiology of infective endocarditis in populations within Africa, published from inception to Jan 14, 2021, irrespective of the language. We used the search terms "endocarditis", "Africa", and the name of all African countries in the search strategy. We excluded articles that did not include primary data, primary studies with a small sample size (<30 participants), and those that report findings from before 1990. We recorded data for study characteristics, sample size, criteria used to define infective endocarditis, risk factors, potential entry site, clinical patterns, microbiology profile, outcomes including complications such as embolic events, heart failure, acute kidney injury, and death, and predictors of death. We used random-effects meta-analysis method to pool estimates. This study is registered with PROSPERO, CRD42021243842.

Findings: We retrieved 2141 records from the database and bibliographic searches, of which a total of 42 studies were included in this systematic review. Rheumatic heart disease was the most common risk factor for infective endocarditis in adults (52·0% [95% CI 42·4-61·5]), whereas congenital heart disease was the most common risk factor for infective endocarditis in children (44·7% [29·5-60·5]). Microbiological testing (mostly blood cultures) was positive in 48·6% (95% CI 42·2-51·1) of patients with infective endocarditis, with Staphylococcus species (41·3% [95% CI 36·2-46·5]) and Streptococcus species (34·0% [29·0-39·3]) the most commonly identified microorganisms. The pooled rate of surgical treatment of infective endocarditis was 49·1% (95% CI 43·2-55·1). The pooled in-hospital mortality rate was 22·6% (95% CI 19·5-25·9). Other frequent complications included heart failure (47·0% [95% CI 38·2-56·0]), acute kidney injury (22·8% [18·8-27·0]), and embolic events (31·1% [22·2-40·7]).

Interpretation: As the most prevalent risk factor in Africa, rheumatic heart disease should be central in interventions to reduce the burden of infective endocarditis on the continent. In tertiary hospitals with good access to cardiac surgery, the outcomes of infective endocarditis seem relatively similar to what has been reported in other parts of the world, especially in high-income countries.

Funding: None.