Unusual winter trend: Delhi sees 7 dengue cases last week

Public health experts said the corporations should ensure anti-mosquito drives are not limited to the post monsoon period.

Delhi reported seven more dengue cases over the past week, taking the number of the vector borne disease in the Capital to 15 this year. This has sparked fears that the aedes aegypti mosquito -- which spreads the dengue virus -- may be adapting to cold conditions.

An MCD worker fumigating an area. Delhi recorded 9,613 dengue cases and 23 fatalities in 2021, making it the second worst annual outbreak on record. (HT Archive)

No dengue cases were reported in the first 15 days of January in 2021, 2020 and 2019.

Public health experts said the corporations should ensure anti-mosquito drives are not limited to the post monsoon period.

Noting that dengue cases used to flatten out during extreme summer and peak winters till a few years ago, Dr BK Tripathi, professor in the department of medicine at Safdarjung Hospital, said that mosquitoes are now adapting to harsh climatic conditions. “The civic bodies need to ensure that preparations and drives against controlling mosquito population should be carried out all through the year,” Dr Tripathi said.

A senior municipal official from public health department said changes in the behaviour of adult mosquitoes needs to be studied more, but added that the increase in reportage may also be due to the disease being notified as notifiable disease in October last year. “The 36 hospitals under the ‘sentinel surveillance system’ used to share weekly data with us but now, corporations are getting data from 180 health care facilities of the city,” the official said.

Delhi recorded 9,613 dengue cases and 23 fatalities in 2021, making it the second worst annual outbreak on record.

Of the 15 cases reported in January so far, three each have been reported in areas under the north corporation and two in East Delhi, while addresses of the remaining seven could not be traced, the report said. Additionally, seven other cases showed that the infections were acquired from other states.

A report by civic bodies shows that 187 cases of mosquito breeding have been detected in this period, as against 46 and 44 in the corresponding periods of 2021 and 2020 respectively.

A senior municipal official from public health official said that 210 legal notices have been issued to property owners for negligence leading to mosquitogenic conditions and prosecution has been launched in 17 cases.

On Friday last week, while hearing a case on the dengue outbreak in the city, the Delhi high court said mosquito infestation and spread of vector-borne diseases are not merely seasonal.

“No doubt they may get heightened during the monsoon period. However, that does not mean other factors are not responsible for mosquito breeding and the spread of vector-borne diseases… It is for the municipal authorities to undertake a campaign to deal with such situations on a daily basis and the menace cannot be addressed only by addressing the problem in particular months of the year,” it said.