Pneumococcal carriage, serotype distribution and risk factors in children with community-acquired pneumonia, 5 years after introduction of the 10-valent pneumococcal conjugate vaccine in Ethiopia

Abstract

Background: There is a scarcity of data on pneumococcal serotypes carried by children in Ethiopia. We studied pneumococcal nasopharyngeal carriage rate, serotypes, and risk factors among children with community acquired pneumonia (CAP). Methods: A prospective observational cohort study was performed in children with CAP, aged 0-15 years, in 2 pediatric emergency departments in Addis Ababa, Ethiopia. Nasopharyngeal swabs were cultured, and serotypes of Streptococcus pneumoniae were determined by sequencing the cpsB gene and by the Quellung reaction. Risk factors were analyzed by using binary logistic regression. Results: Nasopharyngeal swabs were collected from 362 children with CAP. Pneumococcal carriage rate was 21.5% (78 of 362). The most common serotypes were 19A (27%), 16F (8.5%), and 6A (4.9%). In addition, 8.5% of the pneumococcal isolates were nontypeable. In bivariate analysis, children with a parent that smokes were more likely to carry pneumococci (crude odds ratio, 3.9; 95% confidence interval [CI], 1.2-12.3; P =.023) than those with parents that do not smoke. In multivariable analysis, living in a house with >= 2 rooms (adjusted odds ratio [AOR], 0.48; 95% CI, 0.28-0.82; P =.007) and vaccination with = 2 doses of 10-valent pneumococcal conjugate vaccine (PCV10) (AOR, 0.37; 95% CI, 0.15-0.92; P =.033) were protective of pneumococcal carriage. Conclusions: Five years after introduction of PCV10 in Ethiopia, the vaccine-related serotype 19A was predominant in the nasopharynx of children with CAP. Continued evaluation of the direct and indirect impact of PCV10 on pneumococcal serotype distribution in Ethiopia is warranted