Potential vectors of dengue and the profile of dengue in the North-Eastern Region of India : an epidemiological perspective / P. Dutta, J. Mahanta

A comprehensive entomological survey conducted during 2004-2005 in the seven states of the north- eastern (NE region of India revealed that the region is very rich in mosquito fauna, especially Aedes and related species. The known dengue vectors, viz. Aedes Stegomyial aegypti and Aedes (Stegomyial albopictus, being the container breeder mosquitoes, were recorded from all the seven states in the present study, although in earlier surveys, Ae. aegypti was not recorded from Mizoram Nagaland and Tripura. Profuse breeding of these two vectors of dengue was recorded in different container habitats originating from solid-waste materials frequently dumped in urban areas and industrial townships of the region. The breeding potential of Ae. aegypti, the primary vector of dengue in India, was more pronounced showing positive breeding in all types of solid-waste containers than Ae. albopictus, while in rural areas with rich natural vegetation, Ae. albopictus was the dominant species. However, in urban/ industrial areas, the breeding preference of Ae. aegypti was noticed in old tyres, while Ae. albopictus preferred to breed in open battery boxes. Some parts of this region exhibited mild to prominent dengue virus activity particularly for DENV-2, while on one occasion, DENV-4 activity with haemorrhagic manifestations was also observed. In Nagaland, entomological studies carried out at two points of time, 1994 and 2004, provided clear evidence of replacement of Ae. albopictus by Ae. aegypti. With the evidence of dengue vinus activity in the present as well as earlier studies, it is noteworthy that this region could be vulnerable to a widespread dengue outbreak situation in the near future.

Nursing.