Aedes larva density high in Gulshan, Banani, Motijheel, Gopibagh  

Infographic: TBS

A monsoon survey has found a high density of Aedes mosquito larva in the Gulshan and Banani areas of Dhaka North City Corporation as well as in the Gopibagh and Motijheel areas under Dhaka South.  

Conducted between 11 and 23 August by the Directorate General of Health Services (DGHS), the survey recorded the presence of Aedes mosquitoes – which cause dengue fever – in 13.4% of houses under Dhaka North and 11.75% of houses under Dhaka South.

The dissemination of the monsoon survey – carried out in 1,319 households under 40 Dhaka North wards and 1,830 households under 58 Dhaka South wards – will take place at the health directorate at 9am on Wednesday.

Dr Md Ekramul Haque, deputy programme manager of malaria and ATD control programme at the DGHS, told The Business Standard, "The density of Aedes mosquitoes in the monsoon is more than double compared to the pre-monsoon survey released last April."

"Twenty-seven wards of the two city corporations are at high risk of dengue and 15 wards are at medium risk. Once the Breteau Index is more than 20, we consider the area as high risk," he added.

According to the Monsoon Aedes Survey 2022, Dhaka South's Gopibagh, Kamalapur and Motijheel areas have the highest Breteau Index at 53.33 while Dhaka North's Gulshan, Banani and Kalyanpur areas experienced the highest Breteau Index at 36.6.

The Breteau Index indicates the number of positive larvae containers per 100 houses inspected. Under normal conditions, the index of an area should be below 20.

According to the survey, Aedes mosquitoes were present in 45.2% of multi-storied buildings and 24.8% of under-construction buildings, 20.3% of independent houses, 6.8% of slums or semi-pucca houses and 2.8% of vacant plots under Dhaka North.

In Dhaka South areas, mosquitoes were found in 33.0% of multi-storied buildings, 27% of independent houses, 12.1% of slums, and 5.1% of vacant plots.

Khalilur Rahman, senior entomologist of the DGHS, told TBS, "We found Breteau Index to be over 30% in several areas. To control dengue, there is no alternative to destroying Aedes mosquito larvae. For this, initiatives by the city corporations and personal awareness are essential."

"While doing the survey, we have repeatedly found Aedes larvae in the same houses. With limited manpower, the city corporations are working on mosquito control separately. We have to work in community-wise groups to eliminate mosquitoes," he added.

The number of hospitalised dengue patients has been rising in Bangladesh, with 438 more new patients getting admitted to medical facilities across the country in the 24 hours till Tuesday morning.

Of the fresh dengue cases, 315 were hospitalised in Dhaka city and 123 elsewhere, according to data from the health directorate.

The mosquito-borne viral disease has since January this year had 12,007 people get admitted to hospitals across the country, with 45 of them succumbing to the disease.

As many as 1,560 dengue patients, including 1,191 in the capital, are now undergoing treatment at hospitals across the country.

On measures taken to deal with the mosquito menace, Lt Col Md Golam Mostafa Sarwar, deputy chief health officer of Dhaka North, told TBS, "We are working on mosquito control and creating public awareness to prevent dengue. It is not possible for the city corporation or government organisations alone to control Aedes mosquitoes. For this, people will have to do most of the work because the problem happens at homes or around homes."

"We are also working to identify and eradicate mosquito breeding grounds. We will take special action in the areas where the density of mosquitoes is high after receiving the survey report from the health directorate tomorrow (Wednesday)," he added.