SAMIPS-NPC: Southern Africa Mother Infant Pertussis Study, Nasopharyngeal Carriage

项目摘要 百日咳是由百日咳杆菌引起的，是所有传染病中最具传染性的疾病之一， 在所有疫苗可预防的儿科疾病中，控制最差的。由于改用非蜂窝网络 百日咳(AP)疫苗在美国和其他替代疫苗的国家的发病率，已经看到 发病率上升。流行病学和实验数据表明，AP疫苗的一个关键限制是 它们不会阻止无症状的携带和传播。然而，无症状载流子状态的存在 对于百日咳杆菌来说，百日咳从未得到证实，但这是因为这个问题以前从未在 经过适当设计的纵向队列研究，随着时间的推移收集系统的样本和症状。 在之前的出生队列研究中，南非母婴百日咳研究，我们收集了大约20,000 从2000对赞比亚母亲/婴儿从出生到14周大的鼻咽拭子， 症状都是平行编目的。对这组病例的初步分析表明，百日咳在以下人群中很常见 这些婴儿。此外，几乎所有受感染婴儿的母亲也感染了百日咳。 几乎没有人表现出任何症状。这是无症状携带者的推定证据，但仅基于分析。 约占总样本库的10%。我们认为，对此样本库的完整分析可以提供 以前所未有的方式洞察百日咳杆菌的流行病学和传播模式。数据 从这个拟议的分析库中可以回答关于无症状携带的基本问题，其 在母婴配对中的频率和并发性，也将对更新数学 百日咳传播模型，使我们能够第一次回答百日咳在总百日咳中所占的比例 传播是通过无症状链发生的吗？

Project Summary Whooping cough, caused by Bordetella pertussis, is one of the most contagious of all contagious diseases, and the least well controlled of all vaccine preventable pediatric diseases. Since switching to acellular pertussis (aP) vaccines, incidence in the US and other countries that made this vaccine substitution, have seen incidence rates rise. Epidemiologic and experimental data suggest that a key limitation of aP vaccines is that they do not block asymptomatic carriage and spread. However, the existence of an asymptomatic carrier state for B. pertussis has never been proven, but this is because the question has never before been asked in an appropriately designed, longitudinal, cohort study, with systematic sample and symptoms collection over time. In a previous birth cohort study, the Southern Africa Mother Infant Pertussis Study, we collected ~20,000 nasopharyngeal (NP) swabs from 2000 Zambian mother/infant pairs, from birth through 14 weeks of age, with symptoms catalogued in parallel. Preliminary analysis of this set suggests that pertussis is common among the infants. Moreover, nearly all of the mothers of the infected infants were also infected with pertussis, though few showed any symptoms. This is presumptive evidence of asymptomatic carriage, but rests only on analysis of about 10% of the total sample library. We contend that full analysis of this sample library could provide insight into the epidemiology and transmission patterns of B. pertussis in ways never before possible. Data from this proposed analysis of the library can answer fundamental questions about asymptomatic carriage, its frequency, and concurrence within the mother/infant pair, and will also be invaluable for updating mathematical models of pertussis transmission, allowing us to answer, for the first time, what proportion of overall pertussis transmission occurs via asymptomatic chains?