Bureau of Communicable Disease,New York City Department of Health and Mental Hygiene,Long Island City,New York,USA.
Bureau of Epidemiology Services,New York City Department of Health and Mental Hygiene,Long Island City,New York,USA.
Epidemiol Infect. 2018 Oct;146(13):1628-1634. doi: 10.1017/S0950268818002236. Epub 2018 Aug 8.
In 2016, imported Zika virus (ZIKV) infections and the presence of a potentially competent mosquito vector (Aedes albopictus) implied that ZIKV transmission in New York City (NYC) was possible. The NYC Department of Health and Mental Hygiene developed contingency plans for a urosurvey to rule out ongoing local transmission as quickly as possible if a locally acquired case of confirmed ZIKV infection was suspected. We identified tools to (1) rapidly estimate the population living in any given 150-m radius (i.e. within the typical flight distance of an Aedes mosquito) and (2) calculate the sample size needed to test and rule out the further local transmission. As we expected near-zero ZIKV prevalence, methods relying on the normal approximation to the binomial distribution were inappropriate. Instead, we assumed a hypergeometric distribution, 10 missed cases at maximum, a urine assay sensitivity of 92.6% and 100% specificity. Three suspected example risk areas were evaluated with estimated population sizes of 479-4,453, corresponding to a minimum of 133-1244 urine samples. This planning exercise improved our capacity for ruling out local transmission of an emerging infection in a dense, urban environment where all residents in a suspected risk area cannot be feasibly sampled.
2016 年，输入性 Zika 病毒（ZIKV）感染和潜在有能力传播的蚊虫（白纹伊蚊）的存在表明，ZIKV 在纽约市（NYC）的传播是有可能的。如果怀疑有本地获得的确诊 ZIKV 感染病例，纽约市卫生和心理卫生部制定了应急计划，以便尽快进行尿筛查调查以排除持续的本地传播。我们确定了工具来（1）快速估计任何给定 150 米半径内（即白纹伊蚊典型飞行距离内）的人口数量，以及（2）计算进行检测和排除进一步本地传播所需的样本量。由于我们预计 ZIKV 的流行率接近零，因此依赖二项式分布正态逼近的方法是不适用的。相反，我们假设了一个超几何分布，最多有 10 个漏检病例，尿液检测的灵敏度为 92.6%，特异性为 100%。对三个疑似风险区域进行了评估，估计人口规模为 479-4453，对应的最小尿样数为 133-1244。这项规划工作提高了我们在密集城市环境中排除新发传染病本地传播的能力，在这种环境中，不可能对所有疑似风险区域的居民进行采样。
