Impacts of Urbanization on Vector Biology and Transmission of Dengue in China

描述（申请人提供）：中国城市化对登革热病媒生物学和传播的影响。 登革热是中国南方的一个主要公共卫生问题。近年来，我国南方登革热暴发流行间隔时间缩短，疫区不断扩大。由于登革热流行与中国经济发展导致的快速城市化相吻合，因此有人认为城市化为登革病媒的生存和繁殖以及登革病毒的传播创造了有利条件。这一应用检验了中心假设，即城市化导致的环境变化影响了白纹伊蚊的生物学和媒介能力，白纹伊蚊是中国南方的主要登革热媒介。我们将进一步研究过去二十年广州市主要暴发的登革病毒在城市地区的分子流行病学。这项研究的长期目标是确定登革热在城市环境中流行的机制，并制定有效的预防和控制方法。我们设计了以下两个具体目标。首先，我们将确定城市化对白纹伊蚊幼虫和成虫生态的影响，白纹伊蚊是广州地区唯一的登革热媒介，本研究将在广州地区进行。这一目标将检验以下假设：城市化为白纹伊蚊幼虫的生存和发展创造了有利条件，从而增加了登革热病媒的丰度。其次，我们将确定登革热病毒在城市环境中的传播模式。这一目的将检验登革热暴发与登革热病毒新血清型或基因型的引入和传播有关，以及Ae.白纹伊蚊在登革病毒血清型和基因型之间变化，因此最有利的DENV血清型/基因型可能成为流行类型。该研究利用了中国广州独特的登革热流行病学和媒介人群情况，广州经常发生登革热疫情，并利用了Ae。白纹伊蚊在城市环境中繁殖活跃。本研究将显著提高我们对登革热在城市地区传播的认识，并有助于制定有效的登革热监测和控制方案。 公共卫生相关性：登革热在中国造成重大的公共卫生问题;然而，登革热发病频率和规模增加的机制尚不清楚。目前的建议将用于测试的中心假设，即城市化造成的环境变化影响的生物学和矢量能力的Ae。白纹伊蚊是我国南方登革热病毒的主要传播媒介。本研究的结果将有助于确定登革热的流行机制，并制定有效的预防和控制方法。

DESCRIPTION (provided by applicant): Impacts of Urbanization on Vector Biology and Transmission of Dengue in China. Dengue is a major public health problem in southern China. In recent years, the epidemic interval of Dengue outbreaks in southern China has become shorter and the epidemic area is expanding. Because Dengue epidemics coincide with rapid urbanization in China as a result of economic development, it has been suggested that urbanization creates favorable conditions for the survival and reproduction of Dengue vectors and for the transmission of Dengue virus. This application tests the central hypothesis that environmental changes resulting from urbanization affect the biology and vectorial capacity of Aedes albopictus, the major Dengue vector in southern China. We will further examine the molecular epidemiology of the Dengue virus in urban areas for major outbreaks in Guangzhou city in the past two decades. The long-term goal of this research is to determine the mechanisms of Dengue epidemics in urban environments and to develop effective prevention and control methods. We have designed the following two specific aims. First, we will determine the impact of urbanization on the larval and adult ecology of Aedes albopictus mosquitoes, the sole Dengue vector in the Guangzhou area where the present study will be conducted. This aim will test the hypothesis that urbanization creates favorable conditions for the survivorship and development of Aedes albopictus larvae and subsequently, increases the abundance of the Dengue vector. Second, we will determine the transmission patterns of Dengue virus in urban environments. This aim will test the hypothesis that Dengue outbreaks are associated with the introduction and circulation of new serotypes or genotypes of Dengue virus, and that vector competence of Ae. albopictus varies among Dengue viral serotypes and genotypes, and thus the most favored DENV serotype/genotype may become the epidemic type. The proposed research takes advantage of the unique Dengue epidemiological and vector population situations in Guangzhou, China where frequent Dengue outbreaks have occurred and Ae. albopictus is actively breeding in the urban environment. This research will significantly enhance our understanding of Dengue transmission in urban areas, and contribute to the development of effective surveillance and control programs of Dengue in China. PUBLIC HEALTH RELEVANCE: Dengue causes a major public health problem in China; however the mechanisms for increased frequencies and magnitude of Dengue are not clear. The present proposal will use to test the central hypothesis that environmental changes resulting from urbanization affect the biology and vectorial capacity of Ae. albopictus, the major vector of Dengue virus in southern China. The result of this research will be useful to determine the mechanisms of Dengue epidemics and develop effective prevention and control methods for Dengue.