Authorities have failed to control Aedes mosquitoes as the activities taken up in this regard are unscientific, resulting in a surge in dengue cases across the country, a group of entomologists said yesterday.

They were speaking at a press conference, titled "Why this dengue epidemic? What's the solution?", organised by Bangladesh Vector Management Group at the Cirdap Auditorium in Dhaka.

According to them, there is a need for a collaborative approach with the participation of city dwellers in order to bring the mosquito population under control.

Meanwhile, at least 13 more people died from dengue in the last 24 hours since 8:00am yesterday, taking the total number of fatalities to 466. At the same time, 1,983 more patients were hospitalised, raising the total number of cases to 97,860, according to the Directorate General of Health Services.

At the press conference, entomologist Monjur Ahmed Choudhury, who is also chairman of the National River Conservation Commission, said, "The activities taking place under the guise of 'mosquito control' in the country is a farce. Earlier, there were even attempts of controlling mosquitoes using frogs, deer and ducks. Such methods aren't used anywhere in the world."

He added that physicians were assigned to carry out researches on mosquitoes. "This is not their [physicians'] job. Kolkata [city corporation] has been seeing success [in mosquito control] because they made proper use of their entomologists."

Entomologist Dr Saifur Rahman, of National University, said, "We still couldn't develop an effective method of mosquito control. As a result, the dengue outbreak has taken a dangerous turn."

He said the authorities remain confused about their primary focus -- whether to eradicate dengue or to treat the patients.

Lambasting the city corporations, he said, "We have long been asking for a mosquito research centre. We have to know if the mosquitoes alone are carrying the virus or if asymptomatic people are carrying it too … We need to strengthen our serosurveillance."

He also stressed clear and compact planning with a timeline to eliminate mosquitoes and budgetary allocation for the activities.

Entomologist Prof Dr Aslam expressed his skepticism about the authenticity of the bacteria (Bacillus thuringiensis israelensis) imported by Dhaka North City Corporation for mosquito larvae control.

"Spraying BTI may lower mosquito numbers, but it won't provide a lasting solution for dengue and the casualties among patients. Those who have made the decision to uses it should have consulted experts first."

He recommended using multiple methods to control dengue mosquitoes.

Tahmina Aktar, a medical entomologist of Jahangirnagar University, said the information on the presence of Aedes mosquitoes in lakes and canals is completely "unscientific and baseless".

"No one has done any complete study," she said, adding that containers with stagnant water are the main breeding grounds for Aedes mosquitoes.

She also said the latest circulated information on the time that Aedes is most active is also misleading.

"Aedes mosquitoes are mostly active two hours after sunrise and two hours before sunset. They are most likely to bite people during these times."

The experts further said the authorities have been misled by unscientific claims by a few people and are taking up paths that are failing to control mosquitoes and ultimately resulting in human deaths.

Former secretary Margub Morshed and entomologist Indrani Dhara were also present among others.