The Aedes mosquito population will likely decline in Dhaka city in the coming days as the density of the dengue-carrying mosquito larvae is low in the pre-monsoon period this year, according to a survey of the Directorate General of Health Services (DGHS).
The health directorate shared the conclusion Tuesday – after completing its pre-monsoon Aedes larvae density survey. The result has eased the fears of many who feared a fresh dengue outbreak during the novel coronavirus outbreak in Dhaka.
"The health directorate conducted the survey from March 5 to March 15 and covered nearly 3,000 households under 98 wards of the capital," said Dr Shahnila Ferdousi, director of disease control at the DGHS.
"We found the Aedes larvae concentration at zero in 56 wards, while the density at other 37 wards was below 10. The Breteau Index was above ten in only seven areas," she said at an online press briefing on Tuesday.
Entomologists use the Breteau Index to describe the number of positive containers per 100 houses inspected. If any area scores more than 20 percent on the index, entomologists term it risky.
Dr Shahnila said they found the Breteau Index above ten in Dhaka North ward 31 and Dhaka South wards: 15, 16, 18, 28, 41 and 51.
The survey found a higher presence of Aedes larvae in plastic containers — nearly 22 percent of dengue vector larvae was found in such plastic pots.
The health directorate has asked the city's dwellers to remain cautious though the density of aedes mosquito larvae is low.
"Most people are staying home due to the coronavirus pandemic, therefore, household premises and rooftops must be kept clean so that the places do not develop Aedes mosquito larvae," said Dr Shahnila.
She also advised everyone to use mosquito nets at night.
In mid-2019, the country saw the worst dengue outbreak on record with hospitals packed with patients and an increasing tally of deaths and infections.
Mosquito control came under the spotlight in the Dhaka city corporation election manifestos of the two major political parties. The prime minister also reminded the two newly-elected mayors, from Awami League, from the February 1 election, to be more careful about controlling the mosquito menace.
To avert any possible outbreak of mosquito-borne dengue amid the coronavirus pandemic, the health directorate named April of this year dengue and chikungunya prevention month.
Dr Shahnila, at the press briefing, also said that they were working to develop a mobile phone-based app for dengue.
The app will have real-time data on dengue-infected patients, the number of treated and cured people. The application will also show areas with higher dengue risk and the nearby available medical facilities.
The health directorate conducts three surveys — post-monsoon, monsoon, and pre-monsoon — in Dhaka, every year, to examine the presence of Aedes mosquitos.
Earlier, the post-monsoon survey was conducted from December 17 to December 28 at 100 sites under two Dhaka city corporations. The survey covered 1,000 households.