Insecticide susceptibility of Phlebotomus argentipes & assessment of vector control in two districts of West Bengal, India.
OBJECTIVE
Kala-azar or visceral leishmanisis (VL) is known to be endemic in several States of India including West Bengal (WB). Only meager information is available on the vector dynamics of its vector species, Phlebotomus argentipes particularly in relation to control measure from this State. Hence, a pilot study was undertaken to assess the control strategy and its impact on vector in two endemic districts of WB, India.


METHODS
Two villages each from the two districts, Maldah and Burdwan, were selected for the study. Seasonal variation of sandflies was observed during pre-monsoon, post-monsoon and winter seasons. Susceptibility test of P. argentipes against DDT and bioassay on DDT sprayed wall and on long lasting insecticide nets (LN) Perma Net [®] 2.0 were conducted as per the WHO standard methods.


RESULTS
P. argentipes density was high during March to October. Susceptibility status of P. argentipes ranged from 40 to 61.54 per cent. Bioassay test showed 57.89 per cent mortality against LN PermaNet [®] -2.0. and 50 per cent against DDT on wall within 30 min of exposure.


CONCLUSIONS
Despite the integrated vector management approach, the sandfly population was high in the study area. The reason could be development of resistance in P. argentipes against DDT and low effectiveness of LN PermaNet [®] -2.0. The more pragmatic step will be to conduct large studies to monitor the susceptibility level in P. argentipes against DDT.
Vijay
V
Kumar
Lokesh
L
Shankar
Shreekant
S
Kesari
Gouri Shankar
GS
Bhunia
Diwakar Singh
DS
Dinesh
Rakesh
R
Mandal
Department of Vector Biology & Control, Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India.
Pradeep
P
Das
D000818:Animals; D003634:DDT / Q000494:pharmacology*; D019353:Endemic Diseases / Q000517:prevention & control; D006801:Humans; D007194:India; D007303:Insect Vectors / Q000187:drug effects; D007306:Insecticides / Q000494:pharmacology*; D007898:Leishmaniasis, Visceral / Q000517:prevention & control* / Q000635:transmission; D010691:Phlebotomus / Q000187:drug effects* / Q000472:pathogenicity; D012621:Seasons
D007306:Insecticides; D003634:DDT