Objective This work aims to evaluate the factors associated with Streptococcus pneumoniae nasopharyngeal colonization and antimicrobial susceptibility among pediatric outpatients in southwestern Colombia, 2019.

Methods A cross-sectional study was performed using survey-based interviews and the collection of nasopharyngeal-swab specimens for microbiological characterization and antimicrobial susceptibility testing. Logistic regression analyses were performed for factors associated with nasopharyngeal carriage.

Results A total of 452 children under the age of 5 years were examined in which 41.8% carried S. pneumoniae. Higher pneumococcal carriage frequencies were observed among participants aged <2 years and in individuals belonging to indigenous communities, which were lacking established pneumococcal-conjugated vaccine-10 immunization schemes. Additionally, children attending childcare institutions were also highly colonized by pneumococci. S. pneumoniae showed 57.7% nonsusceptibility 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%).

Conclusion The 41.8% of participants carrying S. pneumoniae show a scenario with the presence of multidrug and extensively drug-resistant strains, which constitutes important reservoirs of bacterial transmission by children aged <5 years in Colombia, leading to an onset of pneumococcal diseases. Hence, there is an urgent need to expand conjugate pneumococcal immunization in the community and ensure compliance with established immunization schedules.

目的 本研究旨在评估2019 年哥伦比亚西南部儿科门诊患者肺炎链球菌鼻咽部定植和抗菌药物敏感性的相关因素。

方法 使用基于调查的访谈和收集鼻咽拭子标本进行横断面研究，以进行微生物表征和抗菌药物敏感性测试。对与鼻咽部携带相关的因素进行逻辑回归分析。

结果 共检查452名5岁以下儿童，其中41.8%携带肺炎链球菌。在年龄小于 2 岁的参与者和土著社区的个人中观察到较高的肺炎球菌携带频率，这些社区缺乏既定的肺炎球菌结合疫苗 10 免疫计划。此外，在托儿机构就读的儿童也被肺炎球菌高度定植。肺炎链球菌表现出 57.7% 对苄青霉素不敏感（脑膜炎切除）；对苄青霉素（口服）的中等敏感性为 45.5%，对头孢噻肟的敏感性为 21.7%；对红霉素 (40.7%)、四环素 (36.0%)、甲氧苄啶/磺胺甲恶唑 (24.9%)、克林霉素 (24.3%) 和头孢曲松 (27.0%) 的耐药性。

结论 携带肺炎链球菌的参与者中有 41.8%表现出存在多重耐药菌株和广泛耐药菌株的情况，这是哥伦比亚 <5 岁儿童细菌传播的重要宿主，导致肺炎球菌疾病的发作。因此，迫切需要扩大社区中的结合肺炎球菌免疫接种并确保遵守既定的免疫接种计划。