Gu Weidong, Novak Robert J
Illinois Natural History Survey, Medical Entomology Laboratory, 182 Natural Resources Building, 607 E. Peabody Drive, Champaign, IL 61820, USA.
Am J Trop Med Hyg. 2004 Nov;71(5):636-8.
An important component of arbovirus surveillance is monitoring the vector for presence of the pathogen. Intervention and preventive programs need early detection of arboviral activity in mosquito populations. In this report, we examine the factors affecting the probability of detection of mosquito infections. Since arbovirus infection rates in mosquito populations are very low, observations of zero-infected mosquito samples are common. Using statistical models, we describe methods to estimate the probability of detection and upper bounds of confidence intervals of mosquito infection rates as measures of confidence for observations of zero infection. Our results show that detection of low levels of mosquito infections requires large samples (greater than 1,600 individuals) for a high probability (0.8) of detection. Due to focal transmission of arboviruses, grouping samples over different sampling sites and times is often inappropriate for detection of mosquito infection. We emphasize sample size as a key determinant in detection of mosquito infections and recommend intensified entomologic surveys at sentinel sites to detect arboviral activity.
虫媒病毒监测的一个重要组成部分是监测病媒中病原体的存在情况。干预和预防计划需要尽早发现蚊虫种群中的虫媒病毒活动。在本报告中，我们研究了影响蚊虫感染检测概率的因素。由于蚊虫种群中的虫媒病毒感染率非常低，未感染蚊虫样本的观察结果很常见。我们使用统计模型描述了估计检测概率和蚊虫感染率置信区间上限的方法，以此作为零感染观察结果的置信度衡量标准。我们的结果表明，要以较高概率（0.8）检测到低水平的蚊虫感染，需要大量样本（超过1600只个体）。由于虫媒病毒的局灶性传播，将不同采样地点和时间的样本分组通常不适用于蚊虫感染的检测。我们强调样本量是蚊虫感染检测的关键决定因素，并建议在哨点加强昆虫学调查以检测虫媒病毒活动。
