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

描述(申请人提供)：城市化对中国登革热传播和媒介生物学的影响。登革热是中国南部的一个主要公共卫生问题。近年来，中国南部地区登革热暴发疫情间隔变短，疫区不断扩大。由于登革热疫情与中国经济发展导致的快速城市化不谋而合，因此有人认为，城市化为登革热病媒的生存和繁殖以及登革热病毒的传播创造了有利条件。这一应用验证了中心假设，即城市化导致的环境变化影响白纹伊蚊的生物学和媒介能力，白纹伊蚊是中国南部登革热的主要媒介。我们将进一步研究城市地区登革热病毒的分子流行病学，以应对过去20年来广州市的重大疫情。这项研究的长期目标是确定登革热在城市环境中的流行机制，并开发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。这一目标将检验城市化为白纹伊蚊幼虫的生存和发展创造有利条件的假说，从而增加登革热媒介的丰度。第二，确定登革热病毒在城市环境中的传播模式。这一目标将检验这样一种假设，即登革热疫情与新的登革热病毒血清型或基因型的引入和传播有关，以及Ae的媒介能力。白纹伊蚊在不同的登革热病毒血清型和基因型别之间存在差异，因此最受欢迎的DENV血清型/基因型可能成为流行型。建议的研究利用了广州独特的登革热流行病学和媒介人群情况，以及登革热暴发频繁的中国和Ae。白纹伊蚊在城市环境中活跃繁殖。本研究将大大提高我们对城市地区登革热传播的认识，并为制定有效的中国登革热监测与控制方案做出贡献。 公共卫生相关性：登革热在中国造成了一个主要的公共卫生问题；然而，登革热频率和程度增加的机制尚不清楚。本提案将用来检验中心假设，即城市化导致的环境变化影响Ae的生物学和媒介能力。白纹伊蚊是中国南部登革热病毒的主要传播媒介。这项研究结果将有助于确定登革热流行的机制，并制定有效的登革热防控方法。

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.