Rise in culex population: Mosquito menace grips Dhaka

Abdullah Abbas, a resident of Dilu Road, uses mosquito repellents daily in a desperate attempt to protect his family from the worsening mosquito situation in Dhaka.

The situation has further intensified during the dry season this year.

"The mosquito problem here is extreme. I have to stay under a mosquito net the whole time I'm home," said Abbas.

Culex mosquitoes have made life difficult across many areas of the capital. Many residents say they often take refuge under mosquito nets even when they are not sleeping.

Though recent rains temporarily reduced mosquito numbers, locals report that they return in full force once the weather clears.

Putul Rani, from Shewrapara, said mosquitoes have become so unbearable that it's hard to stay at home.

Fatema Khatun, a housewife from Madhubagh in Moghbazar, added, "The city corporation doesn't spray insecticide here. Usually, coils or sprays help, but during the breeding season, even those don't work. We've been suffering for about a month, but there's been no visible action from the authorities."

The infestation has spread across homes, shops, schools, offices, and courts, frustrating residents over what they say is the lack of an effective response from the city corporations.

Despite using coils, sprays, and nets, many find these methods insufficient. In some areas, children are kept under nets even during the day.

Entomologist GM Saifur Rahman said Culex mosquito populations usually drop during rain and storms. However, in dense urban areas where breeding sites remain unaffected, they persist year-round.

"Minimal control during the dry season contributed to the current crisis," Rahman said.

"City corporations should use BTI [Bacillus thuringiensis israelensis], effective against both Culex and Aedes mosquitoes. But BTI is not yet available in Bangladesh. Instead, we use temephos in drains and malaria oil B, which are often ineffective," he said.

He stressed the need for regular surveillance and consistent control efforts, especially after rain when breeding resumes. BTI is a biological agent that effectively kills mosquito larvae without harming other organisms.

Dhaka North City Corporation Administrator Mohammad Azaz acknowledged the issue, stating that only 70 percent of field workers were performing their duties properly.

"We've decided to involve the army to monitor operations and improve effectiveness. An agreement will be finalised this week," he said.

He said DNCC is also focusing on controlling Aedes mosquitoes.

Meanwhile, Dr Nishat Parveen, acting chief health officer of Dhaka South City Corporation, denied claims of negligence. "DSCC has year-round programmes to control both Aedes and Culex mosquitoes. We've increased insecticide usage and are conducting crash programmes in every ward," she said.

DSCC Administrator Md Shahjahan Mia said, "It's not only the city corporation's responsibility. Residents must keep their surroundings clean. Continuous and coordinated action is essential to tackle the mosquito problem."