Systematic Review and Meta-Analysis on the Aetiology of Bacterial Pneumonia in Children in Sub-Saharan Africa
Abstract BackgroundBefore the introduction of vaccination to protect children from pneumonia, Streptococcus pneumoniae and Haemophilus influenzae type B (HiB) were the most frequent aetiological agents causing bacterial pneumonia in children under five years old. However, under the influence of these vaccines, the aetiology of childhood pneumonia appears to be changing and non-vaccine-type S. pneumoniae, non-typeable H. influenzae, and Staphylococcus aureus are becoming more relevant. MethodsWe conducted a systematic review aimed at identifying the common causes of bacterial pneumonia in children in sub-Saharan Africa. We searched PubMed, Web of Science and African Index Medicus and included primary studies conducted since January 2010 that reported on the bacterial causes of pneumonia in children under five from sub-Saharan Africa. We extracted data items (about the study setting, pneumonia diagnosis, sampling, microbiological methods, and etiological agents) as well as study quality indicators.ResultsEleven studies (published in twelve records), involving 5362 pneumonia cases, were included in our review: nine were case-control studies and two were case series. S. pneumoniae was the most common bacteria identified from blood cultures in children with pneumonia (8%, 95% CI: 4 – 14%), and H. influenzae was the second most common (3%, 95% CI: 1 - 17%). Common isolates from nasopharyngeal swabs were S. pneumoniae (66%), Moraxella catarrhalis (62%), and H. influenzae (44%) were commonly identified in the nasopharynx of children Conclusion S. pneumoniae and H. influenzae remain relevant causes of bacterial pneumonia in children in sub-Saharan Africa. Our review also highlights the ubiquitous occurrence of several potentially pathogenic bacteria in the nasopharynx of children under five group and makes the case for continued research aimed at understanding how nasopharyngeal colonization results in pneumonia.