The authorities of the two city corporations in the capital are testing the efficacy of adulticide samples on culex mosquito although this insecticide was imported to eradicate aedes mosquitos that spread dengue across the country.
The city corporation authorities told New Age that the tests were being done on culex as aedes mosquito samples could not be collected for the efficacy tests.
The Dhaka South City Corporation admitted at a High Court Division hearing on August 1 that the insecticides used to fumigate failed to stamp out mosquitos from Dhaka south City.
Later on the day the High Court directed the local government ministry to import ‘effective’ insecticides within 14 days as dengue already became nationwide epidemic.
Dhaka North City mayor Atiqul Islam told New Age that samples of mosquito control insecticides had been collected to test their efficacy.
He said, ‘We would use the best one.’
Officials of the two city corporation said that before using any insecticide they are tested in a control environment.
Epidemiologists expressed doubts about the efficacy of this method as insecticides fumigated in a controlled environment can’t be equally effective in open environment.
They said that aedes might grow resistance against the use of the same insecticide.
But the city corporation officials said that they were testing insecticide samples on culex before using it in the open environment because culex had greater resistance than the aedes.
Zoological Society of Bangladesh’s former president and also an epidemiologist Manjur A Chowdhury said that city corporation should test insecticide samples on aedes since we are importing them to stamp out aedes.’
He said that resistance power of mosquito depends on many factors but the authority have no study on the issue.
He said that none of the responsible government agencies Dhaka South City Corporation and Dhaka North City Corporation and Institute of Epidemiology Disease Control And Research have no epidemiologists although the agencies are mandated to control mosquitos.
The epidemiologist also asked the city corporation to test the pesticide on wild adult mosquito so that they could count the real picture of its effectiveness.
Both the city corporations used to test the effectiveness of pesticide in a concentrated environment where huge fogging attacked mosquito captive inside net.
The practice of test was very unusual where in the normal situation mosquito could flee any place to another and density of fog also reduces as it comes in touch with air.
City corporation officials said that they have no alternative of the test because mosquito counting was only possible in a control environment.
Some senior mosquito control employee told New Age that once the test took place in open space and knock down of mosquito was counted from white cloths laid under the trees.
Want stories like this in your inbox?
Sign up to exclusive daily email
More Stories from Country