Nasopharyngeal Colonization, Associated Factors and Antimicrobial Resistance of Streptococcus pneumoniae among Children under 5 Years of Age in the Southwestern Colombia

Streptococcus pneumoniae diseases are important causes of children death worldwide. Nasopharyngeal carriage of this pathobiont promotes bacterial spread and infections in the community. Here, a cross-sectional surveillance study was done to determine the proportion of nasopharyngeal colonization, antimicrobial susceptibility profile and associated factors in pediatric outpatients (southwestern Colombia, 2019). Data on factors associated with pneumococcal nasopharyngeal carriage were obtained through survey-based interviews. Nasopharyngeal swabs were collected and bacteria were microbiologically characterized. Antimicrobial susceptibility tests were done by VITEK-2. A logistic regression analysis was performed to examine associated factors. Tests with a p-value <0.05 were considered statistically significant. 452 children from the southwestern Colombia were examined and 41.8% carried S. pneumoniae. A higher pneumococcal carriage frequency was observed among participants <2-years and in individuals belonging to indigenous communities, which were not immunized against pneumococcus, because of lacking established immunization schemes. Additionally, children attending child-care institutions were also highly colonized by pneumococci. S. pneumoniae showed 57.7% non-susceptibility to benzyl-penicillin (meningitis-cut); 45.5% intermediate-sensitivity to benzyl-penicillin (oral-cut) and 21.7% to cefotaxime; and resistance to erythromycin (40.7%), tetracycline (36.0%), trimethoprim/sulfamethoxazole (24.9%), clindamycin (24.3%) and ceftriaxone (27.0%). The proportion of 41.8% of participants carrying S. pneumoniae shows a scenario with the presence of strains resistant to different antimicrobial agents (MDR and XDR), which constitutes important reservoirs of bacterial transmission by children <5-years in the southwest of Colombia. This situation could potentially lead to an onset of pneumococcal diseases. Hence, the need to expand conjugate pneumococcal immunization in the community and ensure compliance with established immunization schedules.