Entomological Survey for New Vector Incrimination and Re-Confirmation of Established Malaria Vectors in Endemic Areas of Bangladesh (4 Sentinel Sites)

Abstract

In Bangladesh malaria is one of the major public health problems and there are 3 malaria endemic hill tract districts which are the major areas among the red zones of malaria enedemicity. This study was aimed at assessment of the new vector incrimination as well as re-confirmation of the established vectors in Naikhangchari, Thanchi, Laxmichari and Baghachari. The anopheline population were collected and tested to incriminate the vector of malaria and their role in transmission, to find out the sporozoite rate, determination of oocyst rate of parasite and entomological innocultaion rate was diagnosed. Anopheline mosquito samples were directly collected from the sites using human bait, cattle landing and CDC light traps. The collected mosquitoes were dissected to find out the sporozoite in the salivary gland, oocyst in the midgut and to see the ovary for determination of the mosquito’s status of parous or nail-parous to determine the length of gonotropic cycle. The highest collection of a primary vector An. philippinensis was in Laxmichari (186 samples) and the highest collection of a secondary vector species An. vagus was in Thanchi (392). After the dissection no sporozoite or oocyst were detected among the collected anopheles’ samples. The vectoral capacity of An. philippinesis should be re-evaluated in the further studies. The pick biting hours of An. philippinensis and An. vagus varied in the 3 study sites which is an important finding of this study.