Delhi is battling one of its worst dengue seasons but the strain that has hit the city is yet to be identified, vital information that will help in better understanding and management of the viral disease.
According to government data, the city had till August 29 reported 831 cases and two deaths. Civic bodies fear the numbers could be much higher. The worst, however, is expected in the second and third week of October, when the mosquito-borne disease normally peaks.
“The report of serotype (virus strain) in circulation in Delhi is awaited,” said a statement from union health secretary BP Sharma, who reviewed the country’s dengue situation on Wednesday.
The process of identification of the strain was underway at All India Institute of Medical Sciences and the result was expected within a week, Sharma said.
“Usually, virus type 2 and 4 are known to have more severe disease manifestations while the remaining two (1 and 3) are less severe,” said a senior researcher at national vector borne disease control programme, requesting anonymity.
The researcher cited the example of influenza — every year there is different strain and the flu vaccine is changed accordingly “that is how this knowledge helps”.
Transmitted by the bite of female mosquitoes, dengue is characterised by high fever, severe pain and nausea. In extreme cases it can cause internal bleeding as blood platelet count drops.
Identifying the serotype helps in knowing the overall pattern, causes, and effects on health and disease conditions.
“This is primarily for doctors and academics to help understand which virus is circulating,” the researcher said.
Experts acknowledge Delhi has seen an upsurge in dengue cases but it still can’t be called an outbreak. “Outbreak is when the numbers are in excess of normal expectancy of the disease for which we consider last five years data. In 2010, Delhi saw a similar situation,” the researcher said. The city reported 6, 259 cases in 2010, the worst on record.