DEN-2 virus among two serotypes found in city

Dengue infection is caused chiefly by four viruses known as serotypes – DEN-1,DEN-2,DEN-3 and DEN-4. According to experts,DEN-2 virus is the most threatening of the four viruses.

“The virus has the probability of camouflaging itself. At present,we have no scientific proof,but the ability of the virus to modulate itself can explain why breeding spots are also found outdoors and not only indoors,” said Dr Om Srivastava,director of infectious diseases at Jaslok hospital.

Dr A C Dhariwal,director of NVBDCP,said,“In 1996,when high cases of dengue were reported in Delhi,DEN-2 virus was the cause of it.”

In the past two months,cases of dengue has seen a sudden rise with more than 30 cases reported every week in the city. While the dengue carrier,Aedes aegypti,has the ability to breed in only domestic places,breeding spots were also found on blue tarpaulin sheets in slums.

According to Rajan Naringrekar,insecticide officer in BMC,35-40 per cent breeding spots are found on blue tarpaulin sheets.

Srivastava said in the past four months,the disease had witnessed a shift in its normal pattern. “The time between the mosquito bite and incubation is getting shorter. People infected with dengue virus are now showing its symptoms quickly. The virus has modulated the immunity response of people it infects,” he said.

BMC’s additional municipal commissioner Manisha Mhaiskar rejected any scope of mutation. However,Dhariwal said,“To confirm mutation,we will have to conduct genotyping,which involves studying the genetic pattern of a virus.”

While the state has recorded 3,583 dengue cases and 33 deaths this year,Mumbai contributes to more than 750 cases and 12 deaths. In addition to it, 615 suspected dengue cases were reported from 38 private hospitals.

tabassum.barnagarwala@expressindia.com