海南岛媒介伊蚊生态及其登革热效能研究

Hainan Island is a tropical area with wide distribution of Aedes mosquitoes, which is a vector of dengue virus. Hainan Island is endemic for dengue and nowadays, dengue fever was frequently reported in the surrounding areas of Hainan Island. There is a high risk of dengue fever outbreak in Hainan Island due to the frequent movement of people associated with international tourism. Vector control is an important way to reduce the transmission of dengue fever. However, there is no systematic study on the ecology and vector competence of Aedes mosquitoes in Hainan Island. Due to the shortage of adult Aedes mosquito surveillance tools in China, first, we planned to use a novel BG Sentinel Trap to study the ecology of Aedes mosquitoes in Hainan Island, including species diversity, distribution, population seasonal dynamics, blood-feeding pattern, adult life span and dengue virus infectivity rate in the wild caught Aedes mosquitoes. Second, we intended to study the vector competence of Aedes mosquitoes (Aedes aegypti and Aedes albopictus) to dengue viruses by establishing an artificial infectivity system. It includes detecting the sensitivity, infectivity and vertical transmission capability of Aedes towards four serotypes of dengue virus. The objective of this project is to study the impact of tropical climates in Hainan Island on the ecology and vector competence of Aedes mosquitoes. Additionally our study is aimed towards predicting the risk of outbreak of dengue fever, and to provide the field and lab information for the control and prevention of dengue fever and other Aedes transmitted diseases in Hainan Island.

海南岛地处热带，媒介伊蚊分布广，是登革热流行区。目前海南岛周边地区登革热暴发流行频繁，作为国际旅游岛，人员流动频繁，登革热暴发流行风险大。媒介控制是减少登革热传播的重要措施，然而目前尚未有海南岛媒介伊蚊系统的生态研究，媒介伊蚊登革热效能研究相对滞后。鉴于国内伊蚊成蚊监测工具存在不足，首先本研究拟运用新型BG Sentinel捕蚊器对海南岛媒介伊蚊的生态进行研究，研究各地区伊蚊的种类、分布、季节消长、吸血宿主、成蚊寿命及登革病毒携带水平。其次拟采用伊蚊实验室体外人工膜饲血感染系统对海南岛媒介伊蚊（埃及伊蚊和白纹伊蚊）登革热效能进行研究，包括媒介伊蚊对I-IV型登革病毒的易感性、传播性和经卵传播能力。本研究目标是通过研究海南岛热带气候对媒介伊蚊生态及其登革热效能的影响，预测海南岛登革热暴发流行的风险，为海南岛登革热及相关伊蚊传播疾病的防控提供现场及实验室依据。

登革热是由登革病毒引起媒介伊蚊传播的病毒性传染病。历史上，海南岛登革热流行强度大，同时其周边地区包括广东、台湾、马来西亚、越南、老挝、菲律宾和柬埔寨等每年都有登革热暴发流行。海南岛作为我国唯一的热带海岛，探究特殊气候和地理位置对媒介伊蚊的生态及其登革热效能的影响，有利于为登革热防控提供重要的数据。研究内容包括：（1）利用新型的BG捕蚊器调查媒介伊蚊在海南的分布、密度及季节消长；（2）利用寿命表法研究登革热重要媒介白纹伊蚊在海南热带气候下的生长、发育、生殖等规律；（3）调查分析海南岛媒介伊蚊幼虫孳生地的类型及分布；（4）研究海南岛重要媒介白纹伊蚊对常规杀虫剂的抗药性；（5）研究海南白纹伊蚊对登革病毒的敏感性。本项目研究发现登革热媒介白纹伊蚊在海南岛广泛分布，在五个研究市县均发现白纹伊蚊，且全年均有白纹伊蚊存在。对屋内、半遮盖和完全遮盖条件下白纹伊蚊生长发育研究发现，半遮盖条件有利于白纹伊蚊羽化及雌蚊的生殖，食物是幼虫发育及化蛹的关键因素。蚊虫孳生水体调查发现，临高县白纹伊蚊具有多样的孳生水体，包括塑料容器、金属容器、排水沟、轮胎、陶瓷容器等。抗药性研究发现，海南白纹伊蚊成蚊对拟除虫菊酯类杀虫剂产生广泛的抗药性，这对于登革热防控具有挑战性。同时，初步探究海口白纹伊蚊对登革2型病毒的敏感性。通过本项目研究，可以为海南岛登革热及相关伊蚊传播疾病的防控提供现场及实验室据。