Epidemiology of dengue in India

Dengue fever is a widespread mosquito borne viral disease in tropical and sub-tropical regions of the world. In India it is an endemic disease in several parts of the country.

Epidemiology of dengue in India: Dengue fever has been known to occur in India for a long time, but dengue hemorrhagic fever was first reported from Calcutta in 1963. Subsequently several outbreaks of dengue fever have been reported.

According to reports as many as 13 states have reported cases of DF/DHF in endemic and epidemic proportions. The disease is reported not only from urban areas but has spread to several rural areas of the country as well.

According to trend data, there is an increase in the number of dengue cases from August onwards, which is post the monsoon season. However, breeding of Aedes mosquitoes begins in June itself. This data indicates that advance planning for dengue prevention and control should be started before June and sustained throughout the rainy season.

Aedes aegypti mosquito is the vector for dengue. Dengue infection is transmitted by the bite of female Aedes mosquito.

Prevalence of dengue in India: A major outbreak of dengue hemorrhagic fever occurred in 1996. During this outbreak,  16517 cases and 545 deaths were reported from all over the country of which 10,252 cases and 423 deaths were reported from Delhi itself. Cases and deaths from dengue were reported from several parts of the country.

After the 1996 outbreak, the number of DF/DHF cases and deaths reported were low up till 2002 (cases-1926 and 33 deaths) but since 2003 rise in dengue cases has been reported. By August 2010, 7262 cases were reported and there were 25 deaths from dengue. For the last 10 years case fatality has been above 1% and most of reported dengue cases and deaths are from the capital city Delhi (outbreaks and deaths from other states often go unreported).

Better mosquito control measures are needed to prevent dengue infection. As the Aedes aegypti breeds almost entirely in man-made water bodies present around households, construction sites and factories, care should be taken to avoid water collections.

If you have dengue like symptoms consult your doctor. The risk of complications and death increases in cases which are not managed properly.