Nasopharyngeal carriage and serotype distribution of Streptococcus pneumoniae among HIV-infected children aged >6 years: before and after vaccination of 13-valent pneumococcal conjugate vaccine

Abstract

Purpose: The objective of this study was to determine the prevalence of colonization, serotype distribution, and antimicrobial susceptibility profile of Streptococcus pneumo-niae (Pneumococcus) isolated from human immunodeficiency virus (HIV)-infected children before and after single-dose of 13-valent pneumococcal conjugate vaccine (PCV13) vaccination. Materials and Methods: We conducted a prospective cohort study among HIV-infected children above six years of age in Jakarta, Indonesia. Nasopharyngeal swabs were col-lected from 50 children before vaccination, 12 months, and 18 months after PCV13 vacci-nation. The swabs were evaluated by bacterial culture, and serotyping were performed using sequential multiplex polymerase chain reactions and Quellung reactions. Antimi-crobial susceptibility profiles were determined using the disk diffusion method. Results: We found Streptococcus pneumoniae colonized 46% (23/50) of total children enrolled before vaccination, which decreased to 19% (n=9/47) at 12 months post-vacci-nation and 29% (14/48) at 18 months post-vaccination. There was no significant difference in the prevalence of pneumococcal colonization between vaccinated and unvaccinated HIV-infected children (p>0.05). There was a significant decrease in pneumococcal colonization between the baseline, 12 months, and 18 months after vaccination among vaccinated children (p<0.05). Vaccine-type (VT) serotypes (6B, 23F, and 19A) were more prevalent than non-vaccine serotypes before vaccination. Non-vaccine type (NVT) serotypes (6C, 15C) were more prevalent at 12 months post-vaccination. VT serotypes were found at 18 months post-vaccination in vaccinated children. There was a high prevalence of antimicrobial resistance to S. pneumoniae isolates to oxacillin, tetracycline, and sulfa-methoxazole-trimethoprim before and after vaccination. Conclusion: There was a decrease in pneumococcal carriage after PCV vaccination in HIV-infected children, accompanied by changes in serotype distribution from VT sero-types to NVT serotypes.