Viral Etiology of Severe Pneumonia Among Kenyan Infants and Children

CONTEXT: Pneumonia is the leading cause of childhood death in sub-Saharan Africa. Comparative estimates of the contribution of causative pathogens to the burden of disease are essential for targeted vaccine development. OBJECTIVE: To determine the viral etiology of severe pneumonia among infants and children at a rural Kenyan hospital using comprehensive and sensitive molecular diagnostic techniques. DESIGN, SETTING, AND PARTICIPANTS: Prospective observational and case-control study during 2007 in a rural Kenyan district hospital. Participants were children aged 1 day to 12 years, residing in a systematically enumerated catchment area, and who either were admitted to Kilifi District Hospital meeting World Health Organization clinical criteria for severe pneumonia or very severe pneumonia; (2) presented with mild upper respiratory tract infection but were not admitted; or (3) were well infants and children attending for immunization. MAIN OUTCOME MEASURES: The presence of respiratory viruses and the odds ratio for admission with severe disease. RESULTS: Of 922 eligible admitted patients, 759 were sampled (82% median age, 9 months). One or more respiratory viruses were detected in 425 of the 759 sampled (56% 95% confidence interval CI, 52%-60%). Respiratory syncytial virus (RSV) was detected in 260 participants (34% 95% CI, 31%-38%) and other respiratory viruses were detected in 219 participants (29%; 95% CI, 26%-32%), the most common being Human coronavirus 229E (n = 51 6. 7%), influenza type A (n = 44 5. 8%), Parainfluenza type 3 (n = 29 3. 8%), Human adenovirus (n = 29 3. 8%), and Human metapneumovirus (n = 23 3. 0%). Compared with well control participants, detection of RSV was associated with severe disease (5% corrected in control participants; adjusted odds ratio, 6. 11 95% CI, 1. 65-22. 6) while collectively, other respiratory viruses were not associated with severe disease (23% in control participants; adjusted odds ratio, 1. 27 95% CI, 0. 64-2. 52). CONCLUSION: In a sample of Kenyan infants and children admitted with severe pneumonia to a rural hospital, RSV was the predominant viral pathogen.