Abstract

Background

Limited information is available on pneumococcal colonization among adults. We studied pneumococcal carriage dynamics in healthy adults using high-sensitivity approaches.

Methods

Eighty-seven adults (25–50 years old) were followed for 6 months in Portugal. Nasopharyngeal, oropharyngeal, and saliva samples were obtained monthly; pneumococcal carriers were also sampled weekly. Carriage was investigated by quantitative polymerase chain reaction (targeting lytA and piaB) and culture. Positive samples were serotyped.

Results

Approximately 20% of the adults were intermittent carriers; 10% were persistent carriers (>4 months). Pneumococcal acquisition and clearance rates were 16.5 (95% confidence interval [CI], 11.2–24.2) and 95.9 (95% CI, 62.3–145.0) cases/1000 person-weeks, respectively. Living with children increased pneumococcal acquisition (hazard ratio, 9.7 [95% CI, 2.6–20.5]; P < .001). Median duration of carriage was 7 weeks and did not depend on regular contact with children.

Conclusions

The pneumococcal carrier state in healthy adults is more dynamic than generally assumed: Acquisition is frequent and duration of carriage is often long. This suggests that some adults may act as reservoirs of pneumococci and hence, depending on the social structure of a community, the magnitude of herd effects potentially attainable through children vaccination may vary. These findings are important when designing strategies to prevent pneumococcal disease in adults.

中文翻译：

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成人肺炎球菌携带动力学：旧范式的新视角

摘要

背景

关于成人肺炎球菌定植的信息有限。我们使用高灵敏度方法研究了健康成人的肺炎球菌携带动力学。

方法

在葡萄牙对 87 名成年人（25-50 岁）进行了为期 6 个月的随访。每月采集鼻咽、口咽和唾液样本；还每周对肺炎球菌携带者进行采样。通过定量聚合酶链式反应（靶向lytA和piaB）和培养来研究载运。对阳性样品进行血清分型。

结果

大约 20% 的成年人是间歇性携带者；10% 是持续携带者（>4 个月）。肺炎球菌感染率和清除率分别为 16.5（95% 置信区间 [CI]，11.2-24.2）和 95.9（95% CI，62.3-145.0）例/1000 人周。与儿童一起生活增加了肺炎球菌感染（风险比，9.7 [95% CI，2.6–20.5]；P  < .001）。平均运输时间为 7 周，不依赖于与儿童的定期接触。

结论

健康成人的肺炎球菌携带者状态比一般假设的更具动态性：获得频繁且携带持续时间通常很长。这表明一些成年人可能是肺炎球菌的宿主，因此，根据社区的社会结构，通过儿童疫苗接种可能达到的群体效应的程度可能会有所不同。在设计预防成人肺炎球菌病的策略时，这些发现非常重要。