Background Streptococcus pneumoniae, or pneumococcus, is a leading cause of morbidity and mortality in children worldwide. Pneumococcal conjugate vaccines (PCV) reduce carriage in the nasopharynx, preventing disease. We conducted a pneumococcal carriage study to estimate the prevalence of pneumococcal colonization, identify risk factors for colonization, and describe antimicrobial susceptibility patterns among pneumococci colonizing young children in Port-au-Prince, Haiti, before introduction of 13-valent PCV (PCV13). Methods We conducted a cross-sectional study of children aged 6–24 months at an immunization clinic in Port-au-Prince between September 2015 and January 2016. Consenting parents were interviewed about factors associated with pneumococcal carriage; nasopharyngeal swabs were collected from each child and cultured for pneumococcus after broth enrichment. Pneumococcal isolates were serotyped and underwent antimicrobial susceptibility testing. We compared frequency of demographic, clinical, and environmental factors among pneumococcus-colonized children (carriers) to those who were not colonized (noncarriers) using unadjusted bivariate analysis and multivariate logistic regression. Results Pneumococcus was isolated from 308 of the 685 (45.0%) children enrolled. Overall, 157 isolates (50.8%) were PCV13 vaccine-type serotypes; most common were 6A (13.3%), 19F (12.6%), 6B (9.7%), and 23F (6.1%). Vaccine-type isolates were significantly more likely to be nonsusceptible to ≥1 antimicrobial (63.1% vs 45.4%, P = .002). On bivariate analysis, carriers were significantly more likely than noncarriers to live in a household without electricity or running water, to share a bedroom with ≥3 people, to have a mother or father who did not complete secondary education, and to have respiratory symptoms in the 24 hours before enrollment (P < .05 for all comparisons). On multivariable analysis, completion of the pentavalent vaccination series (targeting diphtheria, pertussis, tetanus, hepatitis B, and Haemophilus influenzae type b) remained significantly more common among noncarriers. Conclusions Nearly a quarter of healthy children surveyed in Haiti were colonized with vaccine-type pneumococcal serotypes. This baseline carriage study will enable estimation of vaccine impact following nationwide introduction of PCV13.

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肺炎球菌结合疫苗介绍前海地幼儿肺炎链球菌鼻咽携带情况

背景肺炎链球菌或肺炎球菌是全世界儿童发病和死亡的主要原因。肺炎球菌结合疫苗 (PCV) 可减少鼻咽部的携带，预防疾病。在引入 13 价 PCV (PCV13) 之前，我们进行了一项肺炎球菌携带研究，以估计肺炎球菌定植的流行率，确定定植的危险因素，并描述海地太子港肺炎球菌定植幼儿的抗菌药物敏感性模式。方法 我们在 2015 年 9 月至 2016 年 1 月期间在太子港的一家免疫诊所对 6-24 个月的儿童进行了一项横断面研究。就与肺炎球菌携带相关的因素对同意的父母进行了访谈；从每个孩子身上收集鼻咽拭子，在肉汤浓缩后培养肺炎球菌。对肺炎球菌分离株进行血清分型并进行抗菌药敏试验。我们使用未经调整的双变量分析和多变量逻辑回归比较了肺炎球菌定植儿童（携带者）与未定植儿童（非携带者）的人口统计学、临床和环境因素的频率。结果入组的685名儿童中有308名（45.0%）分离出肺炎球菌。总体而言，157 个分离株（50.8%）是 PCV13 疫苗型血清型；最常见的是 6A (13.3%)、19F (12.6%)、6B (9.7%) 和 23F (6.1%)。疫苗型分离株明显更有可能对≥1 种抗菌药物不敏感（63.1% 对 45.4%，P = .002）。在双变量分析中，携带者比非携带者更可能生活在没有电或自来水的家庭中，与 ≥3 人共用卧室，有未完成中学教育的母亲或父亲，以及在之前 24 小时内出现呼吸道症状注册（所有比较的 P < .05）。在多变量分析中，完成五价疫苗系列（针对白喉、百日咳、破伤风、乙型肝炎和 b 型流感嗜血杆菌）在非携带者中仍然更为常见。结论 在海地接受调查的健康儿童中，近四分之一被疫苗型肺炎球菌血清型定植。这项基线携带研究将能够估计在全国范围内引入 PCV13 后的疫苗影响。与 ≥3 人同住一间卧室，母亲或父亲未完成中学教育，并且在入学前 24 小时内出现呼吸道症状（所有比较 P < .05）。在多变量分析中，完成五价疫苗系列（针对白喉、百日咳、破伤风、乙型肝炎和 b 型流感嗜血杆菌）在非携带者中仍然更为常见。结论 在海地接受调查的健康儿童中，近四分之一被疫苗型肺炎球菌血清型定植。这项基线携带研究将能够估计在全国范围内引入 PCV13 后的疫苗影响。与 ≥3 人同住一间卧室，母亲或父亲未完成中学教育，并且在入学前 24 小时内出现呼吸道症状（所有比较 P < .05）。在多变量分析中，完成五价疫苗系列（针对白喉、百日咳、破伤风、乙型肝炎和 b 型流感嗜血杆菌）在非携带者中仍然更为常见。结论 在海地接受调查的健康儿童中，近四分之一被疫苗型肺炎球菌血清型定植。这项基线携带研究将能够估计在全国范围内引入 PCV13 后的疫苗影响。在多变量分析中，完成五价疫苗系列（针对白喉、百日咳、破伤风、乙型肝炎和 b 型流感嗜血杆菌）在非携带者中仍然更为常见。结论 在海地接受调查的健康儿童中，近四分之一被疫苗型肺炎球菌血清型定植。这项基线携带研究将能够估计在全国范围内引入 PCV13 后的疫苗影响。在多变量分析中，完成五价疫苗系列（针对白喉、百日咳、破伤风、乙型肝炎和 b 型流感嗜血杆菌）在非携带者中仍然更为常见。结论 在海地接受调查的健康儿童中，近四分之一被疫苗型肺炎球菌血清型定植。这项基线携带研究将能够估计在全国范围内引入 PCV13 后的疫苗影响。