Prevalence of group A Streptococcal infection in Africa to inform GAS vaccines for rheumatic heart disease: A systematic review and meta-analysis

• Published in: International journal of cardiology Vol. 307; pp. 200 - 208
• Main Authors: Barth, Dylan D., Moloi, Annesinah, Mayosi, Bongani M., Engel, Mark E.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.05.2020
• Subjects: Africa; Group A Streptococcus; Prevalence; Rheumatic heart disease; Systematic review; Vaccine; Group A Streptococcus; Systematic review; Vaccine; Prevalence; Rheumatic heart disease; Africa
• ISSN: 0167-5273; 1874-1754
• DOI: 10.1016/j.ijcard.2019.11.109

The prevalence of group A streptococcal (GAS) disease is estimated at >18.1 million cases with an incidence of >1.78 million cases per year. While a significant cause of mortality and morbidity on the global scale, the burden of GAS disease in Africa is unknown. We conducted a systematic review on the prevalence of GAS disease among children and adults in Africa and the frequency and distribution of emm types among isolates. We performed a comprehensive literature search in a number of databases, using an African search filter. Two reviewers independently selected articles meeting pre-specified criteria and extracted relevant data as per a data extraction form. We applied the random-effects meta-analysis model to aggregate GAS prevalence estimates with 95% CI for GAS prevalence, incorporating the Freeman-Tukey transformation to account for between-study variability. Twenty-five studies were included. Invasive GAS disease prevalence ranged from 0.6% to 10.8% in samples from normally-sterile sites including blood, CSF and soft tissue. A single study reported a prevalence of 74% in skin infections. Prevalence of emm types varied with up to 88 different strains reported, corresponding to a vaccine coverage of 28% to 65%. The pooled prevalence of GAS in persons presenting with pharyngitis was 21% (95% CI, 17% to 26%). The prevalence of GAS remains high among symptomatic individuals residing in Africa. Data on molecular strain characterisation of GAS in Africa is largely non-existent, thus the need for further studies is warranted to inform current prevention efforts including vaccine development. •The prevalence of Group A Streptococcus (GAS) pharyngitis among people living in Africa remains high.•Putative vaccines, based on emm type sequence, have limited coverage of isolates from Africa.•African data on prevalence of GAS-disease are scarce, warranting the need for further studies.