Pandey Siddharth, Das M K, Dhiman Ramesh C
National Institute of Malaria Research, GECH Project site-Ranchi, India.
National Institute of Malaria Research, Field Unit, Ranchi, Jharkhand, India.
J Vector Borne Dis. 2016 Oct-Dec;53(4):327-334.
BACKGROUND & OBJECTIVES: The Ramgarh district of Jharkhand state, India is highly malarious owing to abundance of different malaria vector species, namely Anopheles culicifacies, An. fluviatilis and An. annularis. In spite of high prevalence of malaria vectors in Ramgarh, their larval ecology and climatic conditions affecting malaria dynamics have never been studied. Therefore, the objective of this study was to identify the diversity of potential breeding habitats and breeding preferences of anopheline vectors in the Ramgarh district.
Anopheles immature collection was carried out at potential aquatic habitats in Ramgarh and Gola sites using the standard dipper on fortnightly basis from August 2012 to July 2013. The immatures were reared till adult emergence and further identified using standard keys. Temperature of outdoor and water bodies was recorded through temperature data loggers, and rainfall through standard rain gauges installed at each site.
A total of 6495 immature specimens representing 17 Anopheles species including three malaria vectors, viz. An. culicifacies, An. fluviatilis and An. annularis were collected from 11 types of breeding habitats. The highly preferred breeding habitats of vector anophelines were river bed pools, rivulets, wells, ponds, river margins, ditches and irrigation channels. Larval abundance of vector species showed site-specific variation with temperature and rainfall patterns throughout the year. The Shannon-Weiner diversity index ranged from 0.19 to 1.94 at Ramgarh site and 0.16 to 1.76 at Gola site.
INTERPRETATION & CONCLUSION: The study revealed that malaria vector species have been adapted to breed in a wide range of water bodies. The regular monitoring of such specific vector breeding sites under changing ecological and environmental conditions will be useful in guiding larval control operations selectively for effective vector/ malaria control.
印度恰尔肯德邦的拉姆格尔地区疟疾高发，原因是存在大量不同的疟疾传播媒介物种，即库氏按蚊、溪流按蚊和环纹按蚊。尽管拉姆格尔地区疟疾传播媒介的患病率很高，但从未对其幼虫生态学以及影响疟疾动态的气候条件进行过研究。因此，本研究的目的是确定拉姆格尔地区按蚊媒介潜在繁殖栖息地的多样性及其繁殖偏好。
2012年8月至2013年7月，每两周使用标准水勺在拉姆格尔和戈拉地区的潜在水生栖息地采集按蚊幼虫。将幼虫饲养至成虫羽化，然后使用标准检索表进一步鉴定。通过温度数据记录器记录室外和水体的温度，通过安装在每个地点的标准雨量计记录降雨量。
从11种繁殖栖息地共采集到6495个未成熟标本，代表17种按蚊，其中包括三种疟疾传播媒介，即库氏按蚊、溪流按蚊和环纹按蚊。媒介按蚊高度偏好的繁殖栖息地是河床池、小溪、水井、池塘、河边、沟渠和灌溉渠道。媒介物种的幼虫丰度全年随温度和降雨模式呈现出特定地点的变化。拉姆格尔地区的香农-维纳多样性指数在0.19至1.94之间，戈拉地区在0.16至1.76之间。
该研究表明，疟疾传播媒介物种已适应在广泛的水体中繁殖。在不断变化的生态和环境条件下，对这些特定媒介繁殖地点进行定期监测，将有助于指导有针对性的幼虫控制行动，以有效控制媒介/疟疾。
