A team of department of Zoology, DAV College here, engaged in research on dengue is of the view that the fogging which is being undertaken by district authorities in different localities of the State capital to kill mosquito is erratic and non effective. This team is engaged in research on the vector of dengue, the aedes aegypti and Aedes albopictus mosquito. These varieties of mosquito act as vector of dengue virus and infect humans.
The Head, department of Zoology, DAV college, Dr RK Johri told The Pioneer that the civic authorities engaged in fogging should choose one area and undertake an extensive fogging of this area. He informed that the authorities should undertake fogging on alternate days to be more effective. “It has come to our notice that mosquito get temporarily stung by the erratic fogging but don’t get killed. These insects have also developed resistance to the insecticides which is a big area of concern,’’ he said. The research team has also reached on the conclusion that Aedes infest the urban areas more than rural areas due to which higher number of cases of disease are being reported from the urban areas. On a calming note, Dr Johri said that the serotype study of virus indicate that in Dehradun Den III type virus is prevalent which causes less mortality. The serotype testing is done to identify the type of virus of dengue.
There are four strains of dengue virus and out of these Den II and Den IV are said to be the more lethal than other two.
On being asked to comment on reason behind rising incidence of Dengue in hilly areas where it was uncommon, Dr Johri said that the change in climate is prompting Aedes to ascend the hills and infect the population there. He said that the prevalence of the disease would decrease with the onset of winters as the breeding of the Aedes is reduced in cold conditions.