‘Clean drains round the year,’ says Delhi task force to prevent malaria, dengue

The special task force, constituted to streamline the action plan against mosquito borne diseases, has asked drain owning agencies to speed up desilting of drains and to make the activity a yearlong exercise, unlike the present practise of desilting drains only ahead of monsoon, officials in the know of the matter said.

A senior South Delhi Municipal Corporation official, who was part of the STF meeting held on April 26, said under the current approach, deadlines of May 31 and June 30 have been fixed for completion of the annual desilting exercise. “This allows high mosquito breeding and increased vector density. Under the current conditions, especially with erratic rainfall, this action plan needs to be modified to make it a yearlong exercise,” the official said, asking not to be named.

Another municipal official from the public health department said the STF is now focusing on areas that witness a large influx of people and, hence, is at a higher risk of infection transmission. “High mosquito density does not translate into high number of dengue or malaria cases. It is only after the spread of infection within the mosquito population that a rise in the number of disease cases is observed. We are currently targeting places such as the CRPF camps and police training centres, which have a higher risk of infection transmission,” the second official said, requesting anonymity.

Slow desilting and erratic rain pose problems

Despite very high mosquito densities being observed early this summer, the three municipal corporations have been slow in desilting drains and now only a month remains to meet the annual desilting targets, the data from the engineering departments of the three civic bodies showed.

East Delhi Municipal Corporation (EDMC) claims to have carried out 24.52% desilting work, removing 11,048 tonnes of silt till April 26. A senior EDMC official said a target of 45,065 tons has been set up for the 218 drains spread over 120.7km. “Of the 218 drains, desilting work is in progress in 79 drains,” the official said.

SDMC has been able to remove only 11,534 tonnes of silt which is a third of the target that the civic body has to meet before May 31. North corporation report said 37% of desilting work has been carried out in 815 drains. Due to the slow progress and mosquito breeding in these sites, SDMC public health department has issued fines to 12 officials from the engineering department, an official said.

While the public health departments push for yearlong desilting drives, Delhi has observed waterlogging episodes even during the winter month of January due to erratic rains. Waterlogging and rainfall are directly linked to prevalence of mosquito breeding sites. In January, Delhi recorded 88.2m of rain, the highest ever for January since 1989, when the city recorded 79.7mm of rainfall. Delhi witnessed seven western disturbances in February, not only keeping both the maximum and minimum temperature under checks, but also causing 29.7mm of rainfall that month, the highest ever figure for February since 2014.

Experts have attributed the last year’s rise in dengue cases to the prolonged monsoon season. In 2021, Delhi witnessed an intense monsoon that continued well into late October. The city recorded 1,512.4mm of rainfall till December 29, the second highest ever tally, behind 1,534.3mm of rainfall in 1933.

Delhi recorded 9,613 dengue cases and 23 fatalities in 2021, making it the second worst annual outbreak on record — the dengue outbreak of 2015 had led to 60 deaths and 15,867 infections. The severity of the outbreak last year also prompted the Delhi high court to take suo motu cognizance and a case in this regard continues to be heard by the court