As experts warn of a record increase in Culex mosquito population next month, measures taken by the two Dhaka city corporations to check the blood-sucking insects appear inadequate.
At least two recent surveys -- one by the Directorate General of Health Services (DGHS) and the other by a team of researchers from Jahangirnagar University -- found the mosquito population density in the capital is likely to multiply in the next two weeks.
In the meantime, people in different parts of the city keep complaining about mosquito nuisance. Besides, they said city corporation drives against the insects appear to have become lax after the city corporation elections on February 1.
"It has become totally unbearable as mosquitoes bite both at night and day," said Tapon Chandra Das, a resident of Dogair under Ward-68 of the Dhaka South City Corporation (DSCC).
Tapon said they use mosquito coils and other repellents, but to no avail.
"Several waterbodies in Dogair are virtually breeding grounds of mosquitoes, but the authorities concerned do not take any steps to clean those," he added.
Shariful Islam, who lives in the area, said he had not noticed any anti-mosquito drive after the polls.
Asked, immediate-past councillor of Ward-68 Md Nooruddin Miah said they lacked manpower and logistics support to carry out adequate drives. "We have only three people in our ward for fogging and spraying on a regular basis. We need at least 15 people to cover the area."
"I submitted a request to the DSCC for 15 sprayers, 15 fogging and spray machines, five garbage trucks and 25 sweepers around six months ago, but I haven't received any response yet," he said.
Talking to this correspondent, people in Pallabi, Sutrapur, Mohammadpur, Mirbagh, Kamrangirchar, Manda, Sonir Akhra, Dhonia and several other areas shared similar experience.
Entomologist Dr Manzur Chowdhury, former president of Geological Society of Bangladesh, said the number of Culex mosquitoes, which spread diseases like filariasis and avian malaria, has gone "out of control" in Dhaka.
Lack of effective measures by the two city corporations and the absence of proper logistics are mainly to blame for the situation, he said, adding that covered manholes aggravate the problem.
Sprays cannot reach the stagnant water beneath the covered manholes, which then becomes ideal breeding grounds for Culex, he explained.
Dr Manzur said the Dhaka North City Corporation (DNCC) had taken initiatives to destroy mosquito hotspots, identified by entomologists last November at the beginning of "Culex Season".
But the activities to check the mosquitoes came to a halt during the mayoral and councillor elections in the two city corporations, he mentioned.
"I have not seen any fogging near my home on Banani Road-16 since then," he said.
"If city corporations do not start taking effective measures now, the increasing trend in mosquito population density will continue until a nor'wester hits the capital. The storm naturally kills Culex mosquitoes and reduces their number," he added.
In a recent survey, the DGHS has found more than 200 mosquito larvae in samples of 500ml of water taken from most swamps, drains, and stagnant waterbodies in areas under the two city corporations.
Jahangirnagar University's entomologist Kabirul Bashar, along with a team of researchers, has been conducting similar surveys on the capital's waterbodies under a three-year project.
He explained that until this year, the highest density of Culex mosquito larvae was found in January. It was 50 larvae in 500ml of water.
"This year, for the first time, we found about 150-200 larvae in 500ml of water in a survey conducted between February 11 and 18 in the two city corporation areas," he said.
"Rise in temperatures from mid-February is leading to increase in organic matter in waterbodies, which provides food and a conducive breeding environment to mosquitoes. Existing larvae will mature in the next 15 days. The situation will turn dire, unless larvicide is sprayed," he added.
Contacted, Chief Health Officer Brig Gen Sharif Ahmed of DSCC said they take measures round the year to check the population of Aedes mosquitoes, which spread dengue, chikungunya and other diseases. From November to March and April, they take steps to check Culex, he said.
On Monday, the DSCC issued a press release in which it announced a week-long crash programme, starting on Tuesday, to identify and destroy mosquito breeding grounds in the city.
Sharif said they were applying malaria Oil-B, apart from their regular pesticides, to get better result following the suggestions of entomologists.
Health Officer Dr Mohammad Emdadul Haque of the DNCC said they had already started a two-week crash programme against mosquitoes, which will end next Thursday. "We are hoping to check mosquitoes in March," he added.