Showing no signs of waning, dengue has already claimed three young lives in Delhi and over 1,400 people have tested positive since January, according to the Delhi government.
Private hospitals, however, claim that the numbers are almost thrice of what has been reported by the government and hospitals in the city are flooded with patients with dengue fever and symptoms.
Delhi is staking claim to world-class city status but it has not been able to check this vector-borne disease over many years. Doctors say newer strains are coming to light now.
Delhi Municipal Corporation health officer N.K. Yadav said that this year, transmission through Aedes albopictus mosquitoes (also known as the Asian tiger) has been found. “It could be the reason for the recent spike in dengue cases. Though not much is known about this species, we have found that it carries dengue-causing virus. This mosquito breeds in the open and was first identified in southern India.”
Dr. Yadav said: “This year, Delhi started reporting a large number of dengue cases from the last week of September, and the number of new cases is yet to decline, in spite of a drop in temperature. The maximum number of cases is from South and Central Delhi, with the South Delhi Municipal Corporation confirming a peak of over 509 cases this year. This could be because of high human density, greenery, lack of civic agencies and the residents’ inability to check mosquito breeding.”
“The Delhi government has intensified its checks on mosquito breeding and has also appealed to residents to support the civic agencies and prevent the spread of malaria, dengue and chikungunya,” Dr. Yadav said.
The Delhi Municipal Corporation’s records also show that unlike other vector-borne diseases, dengue seems to carry a bias towards the higher economic zones. The mosquitoes primarily breed in clean stagnating water in households. Larvae were detected by civic squads in coolers, flower pots and uncovered water tanks in posh colonies. Breeding was also found in several government hospitals, buildings and schools.
“Since there is no treatment for dengue, the only way out is prevention of mosquito breeding and bites,” said Health Minister A.K. Walia. After the city witnessed an increase in the number of cases, the government directed government hospitals and blood banks to ensure that there were enough blood components and beds.
“One reason for the discrepancy in the Delhi government and private hospitals dengue figures is our insistence on confirming dengue through an IgM Capture, or Elisa test for both antigen and antibody. The Elisa test has higher sensitivity and specificity level. Most private hospitals use rapid NS1 antigen tests whose results we don’t accept to record dengue cases. We have now asked private hospitals to also report all dengue cases so that we have actual data about the number of cases and deaths due to the viruses. The good news for Delhi is that some hospitals here are now reporting fewer dengue cases and we hope that with the further drop in temperature dengue cases will come down significantly,” Dr. Walia said.
Stating that dengue had become endemic to India with outbreaks occurring almost every year and the capital seeing a large number of cases, Indian Medical Association member Anil Bansal noted: “This year has been unique for the city with dengue patients coming in with cross infections, including typhoid and symptoms of viral fever. Since September, Delhi has been the hotbed for infections, with dengue, malaria and viral infections topping the charts.”
“Over the years, Delhi has been reporting all the four serotypes of the virus, and every year, we have a dominate type,” said Sir Ganga Ram Hospital consultant physician Atul Gogia. There was no vaccine available for dengue, and hospitals only offered supportive treatment.
“Children, older people and those with compromised immunity are at the maximum risk,” said Dr. Gogia. Delhi, he noted, had witnessed outbreaks caused by various dengue virus types over the years, and incidence figures were low after the 1996 epidemic for the next six years till the big upsurge occurred during 2003, which saw all four serotypes for the first time. Later, 2010 saw 5,682 cases being reported with eight deaths by this time of the year.