Aedes Mosquitos: They’re breeding in construction sites

Clear and stagnant water at construction sites are the most hospitable breeding ground for Aedes mosquitoes and steps should be taken immediately to address the problem, experts said.

According to the survey of the Communicable Disease Control division of Directorate General of Health Services (DGHS), flooded basements, plastic barrels and water tanks at construction sites are the prime breeding grounds for Aedes .

Among breeding sources, flooded floor basement has accounted for 11.69 percent of Aedes breeding, plastic drum 22.08 percent, plastic bucket 10.39 percent, water tank 9.09 percent, hole for water metre 9.09 percent, elevator shaft 5.19 percent, mineral water jar 3.90 percent, clay pot 2.60 percent, paint pot 2.60 percent, others 15.58 percent, according to the findings.

The 10-day survey was conducted between March 5 and March 14 in 2,996 houses in 100 neighbourhoods of 98 wards of the two city corporations in Dhaka.

Shahnila Ferdousi, line director of Centre for Disease Control at DGHS, said 72 houses out of 2,996 were found Aedes positive.

She said they have provided the findings to the city corporations and other authorities concerned to take necessary steps to destroy the breeding grounds.

Shahnila also urged everyone to clean their own houses, gardens, roofs and roof gardens to eradicate Aedes mosquitoes, adding that everyone should use mosquito nets while sleeping.

She said they have given instructions to all civil surgeons of districts across the country to also prioritise suspected dengue patients when someone comes to the hospital with a fever.

It does not necessarily mean that a person coming in with fever is infected with Covid-19; the patient could be suffering from dengue as well, she said.

"We have distributed around 44,000 kits to 68 districts to distribute at upazila level in order to diagnose dengue," she said.

New doctors in upazila hospitals were trained on dengue patient management in January, she added.

According to the DGHS data, 289 dengue-infected patients were hospitalised in different parts of the country since January, of whom 64 were outside Dhaka.

Brig Gen Mominur Rahman Mamun, chief health officer at Dhaka North City Corporation, said they are applying larvicide and adulticide every day.

He said a meeting was held in Local Government Division where the LGRD minister directed all stake holders like Rajuk, Wasa, Desa and BRTC to take necessary steps to destroy the breeding grounds. "We have issued letters recently to them, so that they address this issue properly," he said.

Mamun said they also applied adulticide and larvicide at construction sites but it was not possible for their spray men to do the job properly as many spaces were inaccessible. So, it is the duty of the owners of the building or construction authorities to take the necessary steps in this regard, he added.

He said abandoned cars in front of police stations, abandoned vehicles in BRTC bus depots, abandoned tyres in bus stops are also a major source of Aedes mosquitoes and that authorities concerned will have to take necessary steps.

Mamun said they are also taking steps through advertisements or through social media to make people aware of the problem as it is now not possible to conduct door-to-door information campaigns because of the countrywide shutdown.

Chief Health Officer of DSCC Brig Gen Sharif Ahmed said they are applying adulticide and larvicide twice a day.

In addition, they are also applying antiseptic through water browsers.

He said they are also focusing on construction sites, so that Aedes mosquitoes do not breed there.

Entomologist Kabirul Bashar of Jahangirnagar University said the light rain last week had helped the breeding of Aedes and it would take 15 days for the larvae to become adult mosquitoes.

Cleaning activities and awareness campaigns should be launched across the country, he added.

Train stations, bus stops, and police stations should be cleaned, he said.

The construction site owners should be very careful. At such sites, the authorities should use bleach in the ditches, containers and reservoirs, he added.

He pointed out that in union and upazila parishads, there is no equipment to control mosquito infestation.

Clear and stagnant water in discarded containers, flooded floors, water reservoirs, plastic drums at construction sites may eventually become sources of armies of mosquitoes in the coming weeks, he feared.

He also urged that necessary steps be taken to keep different government and private structures clean during this shutdown.