Some observations on abundance and breeding habitats of Anopheles sp. in Trincomalee, Sri Lanka

Abstract

Malaria is one of the most serious vector-borne diseases affecting millions of people in the world annually. More than 90% of the deaths, resulting from malaria occurred particularly in children aged 1-5 years. Despite the huge burden and the absence of an effective vaccine, few tools are available to control malaria. Malaria is transmitted by Anopheles mosquitoes. The abundance of Anopheles mosquitoes was not studied in some parts of the island, especially in North and East areas over 30 years because of the ethnic conflict. The main aim of this study was to explore the habitat range and distribution of Anopheline species in the Trincomalee district. Five hundred and seventy one Anopheles larvae were collected from different breeding sites in 5 areas (Sirajnagar, Hatharaela, Paraipanchankulam, Indiwewa and Uppuweli) in Trincomalee district in March 2010 using standard larval collection techniques. These areas were situated about 10 km apart from each other. Collected mosquito larvae weretransferred to the laboratory and reared. Emerged adult Anopheles mosquitoeswereidentified using taxonomic keys. Nine anopheline species wererecorded: Anophelesculicifacies 6% (32/571), An. subpictus 25% (145/571), An.vagus 23% (134/571), An. peditaeniatus 5% (28/571), An. nigerrimus 35% (200/571), An. barbirostris 2% (14/571), An.jemesi 1% (7/571), An. pallidus 0.3% (2/571) and An. varuna 0.3% (2/571). Overall, Anopheles nigerrimus, An. subpictus and An. Vagus were the most prevalent, and An. culicifacies, An. peditaeniatus, An. barbirostris, An. jemesi, An. varuna and An. pallidus were the least prevalent species. Paddy fields, burrow pits, field channels, ponds, irrigation channels, edges of tanks, mud pools and marshy lands were the main breeding sites of Anopheles mosquitoes in selected areas in Trincomalee district. The presence of some Anopheline mosquitoes which can act as potential malaria vectors may cause malaria epidemics in these areas. Acknowledgements: Financial assistance from the Global Fund for Aids, Tuberculosis and Malaria (GFATM) (Round 8)