Indoor and outdoor density of adult Phlebotomus argentipes the vector of Visceral leishmaniasis in an endemic foci of Bihar India

Chandrima Das; Shilpa Raj; A.K.Mukhopadhyay

Volume : VIII, Issue : I, January - 2018

Indoor and outdoor density of adult Phlebotomus argentipes the vector of Visceral leishmaniasis in an endemic foci of Bihar India

Chandrima Das, Shilpa Raj, A. K. Mukhopadhyay

Abstract :

Since, 1976 to 2014, DDT, and from 2015 till date, alpha cypermethrin insecticide is being sprayed for two rounds per year as indoor residual spray up to 1.8 meter i.e 6 feet height in human dwellings as well as in cattle sheds in Bihar, India, as a part of Kala –azar elimination programme. This is being practiced out of the belief that Phlebotomus argentipes the vector of kala azar is endophilic in nature and cannot hop beyond 6feet (1.8 meters) height. A sixteen months study was therefore conducted in three villages in a kala azar endemic block Warisnagar, district Samastipur, Bihar from September 2016 to November 2017 to note the vertical distribution of P.argentipes in indoors and their distribution in outdoors. In all the three study villages, density of adult P.argentipes was found more in Cattle sheds than in human dwellings. Irrespective of IRS and non IRS villages, significant numbers (p value 0.47) of P.argentipes were found above 1.8 meter (above 6 feet) in CS and HD of which 33.37 percent blood fed and gravid females. Sizable number of P.argentipes was also found in outdoor peridomestic situations throughout the study period. Therefore it may be the time to evaluate vector control strategies in kala azar endemic areas of Bihar for successful elimination of the disease from India.