No abstract

Streptococcus pneumoniae is an important cause of infection and commonly colonizes the nasopharynx of young children, along with other potentially pathogenic bacteria. The objectives of this study were to estimate the carriage prevalence of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus in young children in Indonesia, and to examine interactions between these bacterial species. 302 healthy children aged 12–24 months were enrolled in community health centers in the Bandung, Central Lombok, and Padang regions. Nasopharyngeal swabs were collected and stored according to World Health Organization recommendations, and bacterial species detected by qPCR. Pneumococcal serotyping was conducted by microarray and latex agglutination/Quellung. Overall carriage prevalence was 49.5% for S. pneumoniae, 27.5% for H. influenzae, 42.7% for M. catarrhalis, and 7.3% for S. aureus. Prevalence of M. catarrhalis and S. pneumoniae, as well as pneumococcal serotype distribution, varied by region. Positive associations were observed for S. pneumoniae and M. catarrhalis (OR 3.07 [95%CI 1.91–4.94]), and H. influenzae and M. catarrhalis (OR 2.34 [95%CI 1.40–3.91]), and a negative association was found between M. catarrhalis and S. aureus (OR 0.06 [95%CI 0.01–0.43]). Densities of S. pneumoniae, H. influenzae, and M. catarrhalis were positively correlated when two of these species were present. Prior to pneumococcal vaccine introduction, pneumococcal carriage prevalence and serotype distribution varies among children living in different regions of Indonesia. Positive associations in both carriage and density identified among S. pneumoniae, H. influenzae, and M. catarrhalis suggest a synergistic relationship among these species with potential clinical implications.

Nasopharyngeal carriage of Streptococcus pneumoniae underpins disease development and transmission. This study was performed to examine pneumococcal carriage dynamics, including density and multiple serotype carriage, in Indonesian infants during the first year of life. Methods: Two hundred healthy infants were enrolled at 2 months of age. Eight nasopharyngeal swabs were collected from enrolment until 12 months of age. Pneumococci were detected using quantitative PCR and serotyped by microarray. Regression models assessed factors influencing pneumococcal carriage and density. Results: Eighty-five percent of infants carried pneumococci at least once during the study. The median age at first acquisition was 129 days (interquartile range 41-216 days). The median duration of carriage was longer for the first pneumococcal acquisition compared with subsequent acquisitions (151 days vs. 95 days, p < 0.0001). Of the 166 infants who carried pneumococci during the study, the majority (63.9%) carried a single pneumococcal serotype at a time. Pneumococcal carriage density was higher when upper respiratory tract infection symptoms were present, lower during antibiotic usage, decreased with age, and tended to decrease over time during a carriage episode. Conclusions: The majority of Indonesian infants carry pneumococcus at least once during the first year of life. Pneumococcal carriage is a dynamic process, with pneumococcal density varying during a carriage episode.