The country is already grappling with a rise in deadly dengue cases, and the ongoing rainy weather has stirred up fears of further deterioration of the situation.

Experts say intermittent rains and high humidity are very suitable for Aedes aegypti mosquitoes, the known carrier of the dengue virus, to breed. Such weather also increases their biting tendency.

The Directorate General of Health Services (DGHS) has reported 27,705 hospitalisations because of dengue this year until yesterday morning. A total of 143 dengue patients have died in this period.

More than half of the cases were reported in September during which the death toll jumped by 60 so far.

Entomologist Professor Kabirul Bashar of Jahangirnagar University said the situation will worsen in October if necessary measures are not taken immediately.

A field-level survey led by Prof Bashar showed a high density of Aedes mosquitoes in the capital.

The surveyors are using the Breteau Index (BI), an early warning signal to predict a possible outbreak of dengue fever. They are monitoring five sentinel sites in Uttara, Gulshan-Banani, Mohammadpur, Mirpur and Gabtoli and found BI between 33 and 93. BI exceeding 20 is risky, according to experts.

As the local government representatives were removed after the fall of the previous government in August, those in charge now will have to take the necessary steps in consultation with experts, Prof Bashar said. 

Entomologist Manzur A Chowdhury, who also believes the ongoing rain will escalate the dengue situation, called for awareness among the people.

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"Social awareness against dengue is very much absent now because people are taking this matter very lightly," he said. "They will have to be very aware as the number of cases and deaths are growing."

Manzur said if the weather pattern – high humidity and intermittent rains – persists, the number of dengue cases will peak in October.

He suggested protective measures to prevent dengue. Mosquito repellents should be used in every house in the morning and afternoon when Aedes mosquitoes bite.

People, especially children, will have to wear full-sleeve dresses and use mosquito nets while sleeping during daytime or night, he added.

He said people will have to clean all the containers in and around their houses if there is any stagnant water after rain because Aedes mosquitoes breed in such clean water.  

Manzur also encouraged big organisations like housing societies to use Bacillus thuringiensis israelensis (Bti), a naturally occurring soil bacterium that can effectively kill mosquito larvae present in water.

He stressed the need to carry out anti-mosquito drives at hospitals as the chances of Aedes mosquitoes carrying the dengue virus are high because of the presence of patients.

As a long-term initiative, Manzur also suggested establishing a vector management unit by upgrading the Dhaka Mosquito Control Office where different works like research, training, monitoring, and surveys will be carried out.

"This will be a specialised organisation that will work on vector management and city corporations will also do some work like cleaning drains and managing garbage," Manzur said.

Entomologist GM Saifur Rahman sees "no possibility" of the dengue situation improving now as the pattern of rain is very suitable for Aedes mosquito breeding. Such rain will not wash out Aedes larvae or eggs.

If the authorities do not take necessary measures now, dengue cases in the most vulnerable places will increase further, Saifur said.

"The situation will even worsen in October," he added.

In response to the ongoing dengue outbreak, the government on September 23 formed 10 teams to ensure implementation, coordination, and supervision of mosquito eradication efforts across the country.

Of the newly-formed teams, four will focus on Dhaka South City Corporation, while three will operate in Dhaka North City Corporation. Separate teams have also been assigned to Narayanganj, Gazipur, and Chattogram city corporations, with additional teams covering other major cities.