Not much being done to stop dengue outbreak

Despite a record-breaking outbreak last year, with more than 1,705 deaths, the authorities concerned are yet to establish a comprehensive surveillance system to track and control the Aedes mosquitoes, the carrier of the deadly dengue virus.

Experts and public health officials, who have been calling for an effective surveillance system in place, are worried about a potential resurgence of the dengue during the upcoming monsoon season, a time generally sees a spike in dengue cases.

They said it is not possible to control Aedes mosquitoes without a round-the year-surveillance system to find hotspots of the mosquitoes and knowing the trend and serotypes of the virus.

Most of the 980 dengue deaths last year were recorded in Dhaka, yet the action taken by the two city corporations, responsible for controlling Aedes mosquitoes, has hardly been seen.

Only this month, Dhaka North City Corporation started surveillance on a small scale by setting up three types of traps at 20 points in DNCC areas. There was no such move from the Dhaka South City Corporation as of now.

"Aedes mosquitoes should be controlled through scientific and systematic ways, but that is still absent," entomologist GM Saifur Rahman told The Daily Star.

He said both the city corporations are still depending on the results of three surveys, carried out by the health directorate, to take their measures.

Saifur, also an assistant professor at National University, said there is a lack of records of Aedes mosquitos' clusters (hotspots).

"Keeping records of dengue clusters through surveillance is very important, but there is no surveillance system across the country," he said, adding that there is no lab to conduct surveillance and find the trend of dengue virus.

At least 32 dengue patients died and 2,545 were hospitalised across the country as May 15, according to the data of Directorate General of Health Services (DGHS).

The numbers were 13 and 2,022 till May last year.

The country recorded 3,21,179 dengue cases last year, including 1,10,008 in Dhaka.

Prof Kabirul Bashar, an entomologist at Jahangirnagar University, said a recent survey conducted by the university found high density of Aedes mosquitoes in Dhaka, Cox's Bazar, Chattogram, Barishal, Barguna, Chandpur, and Gazipur.

"If the authorities concerned can take effective measures right now, it is still possible to control the Aedes mosquitoes. Otherwise, there is a possibility of crossing the number of last year's dengue cases," he said.

Brig Gen Imru-al-Quais, chief health officer of DNCC, said they recently set up 20 mosquito-catching traps at five zones of the corporation as part of Aedes mosquito surveillance.

He said they have a plan to set up 200 traps.

"Through this surveillance, we will know some information like density of the Aedes mosquito, its types, and the effectiveness of our measures."

Surveillance is very important before starting any work, Quais said, adding that they are taking measures based on the surveillance.

A US expert team will visit Bangladesh shortly to observe the surveillance of DNCC and give their advice on it, the official said.

Fazle Shamsul Kabir, chief health officer of DSCC, said they do not have any entomologist, but they are taking measures through their officials and employees to be vigilant in the DSCC areas.

He said they are taking steps based on their previous data and continuous observation of the mosquito control workers and supervisors.

Kabir said they have plans to appoint an entomologist and set up a lab, but that would take time.

WHAT CAN BE DONE?

Prof Bashar suggested having a proper solid waste management system in place, destroying possible breeding containers, applying an insect growth regulator (IGR) or Bacillus thuringiensis israelensis (Bti) where applicable and conducting extensive drives in and around the houses of dengue patients to kill adult mosquitoes.

He recommended introducing online registration of patients for having accurate data of dengue cases as it is very important to take effective measures.

Saifur stressed the need for conducting surveillance immediately so the hotspots of Aedes mosquitoes and larvae can be identified. "Effective measures will have to be taken to destroy adult mosquitoes and larvae."

Bti or the same kind of insecticide is also needed to be applied at the hotspots, he added.