Department of Biology, University of Florida, Gainesville, Florida, United States of America.
Department of Mathematics, University of Florida, Gainesville, Florida, United States of America.
PLoS Comput Biol. 2014 Jun 26;10(6):e1003668. doi: 10.1371/journal.pcbi.1003668. eCollection 2014 Jun.
The early detection of disease epidemics reduces the chance of successful introductions into new locales, minimizes the number of infections, and reduces the financial impact. We develop a framework to determine the optimal sampling strategy for disease detection in zoonotic host-vector epidemiological systems when a disease goes from below detectable levels to an epidemic. We find that if the time of disease introduction is known then the optimal sampling strategy can switch abruptly between sampling only from the vector population to sampling only from the host population. We also construct time-independent optimal sampling strategies when conducting periodic sampling that can involve sampling both the host and the vector populations simultaneously. Both time-dependent and -independent solutions can be useful for sampling design, depending on whether the time of introduction of the disease is known or not. We illustrate the approach with West Nile virus, a globally-spreading zoonotic arbovirus. Though our analytical results are based on a linearization of the dynamical systems, the sampling rules appear robust over a wide range of parameter space when compared to nonlinear simulation models. Our results suggest some simple rules that can be used by practitioners when developing surveillance programs. These rules require knowledge of transition rates between epidemiological compartments, which population was initially infected, and of the cost per sample for serological tests.
疾病的早期检测可降低疾病成功传入新环境的机会，减少感染数量，并降低经济影响。当疾病从可检测水平以下发展为流行时，我们开发了一个框架来确定在人畜共患病宿主-媒介流行病学系统中进行疾病检测的最佳采样策略。我们发现，如果知道疾病的传入时间，则最佳采样策略可以在仅从媒介种群采样和仅从宿主种群采样之间突然切换。当进行定期采样时，我们还构建了时间独立的最佳采样策略，其中可以同时采样宿主和媒介种群。根据是否知道疾病的传入时间，这两种时间相关和独立的解决方案都可以用于采样设计。我们用西尼罗河病毒（一种在全球范围内传播的人畜共患病虫媒病毒）来说明这种方法。尽管我们的分析结果是基于对动力系统的线性化，但与非线性模拟模型相比，在广泛的参数空间中，采样规则似乎具有很强的鲁棒性。我们的结果提出了一些简单的规则，从业者可以在制定监测计划时使用这些规则。这些规则需要了解流行病学隔室之间的转移率、最初感染的种群以及血清学检测的每个样本的成本。
