Atomic Energy Commission’s lab breeds sterile male pupas to subdue aedes population
Amidst a worsening dengue situation, government now decides to deploy sterile mosquitoes, bred in the laboratory, to suppress the population of aedes, a dengue vector.
Bangladesh Atomic Energy Commission’s (BAEC) Atomic Energy Research Establishment (AERE) in Savar has applied gamma ray irradiation to sterilize thousands of mosquito pupas. While they remain sexually competitive, they cannot produce offspring.
Sterile insect technique, or SIT for short, is a pest control method involving the mass-rearing and sterilization, using radiation, of a target pest, followed by the systematic area-wide release of the sterile males by air over defined areas, where they mate with wild females resulting in no offspring, and a declining pest population.
Upon visiting the AERE lab on Saturday Science and Technology Minister Yeafesh Osman asked the scientists to take the sterilized mosquitoes to the field level soon.
Dr Md Aftab Hossain, a principal scientific officer of Insect Biotechnology Division of the Institute of Food and Radiation Biology of the AERE, told Dhaka Tribune last night that two experts from the International Atomic Energy Agency (IAEA) will come soon to provide further support for its sterile mosquito program.
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“But it’s highly unlikely that we’ll be able to release the lab-bred sterile ones into the environment during the current dengue season. It’ll require some time, logistics, and capacity building,” explained Dr Aftab, who is involved with the institution’s SIT program.
Though the AERE lab succeeded in breeding sterile mosquitoes back in 2017, the move to deploy the same to the environment comes only days after media reports showing SIT’s success in containing dengue vector in China.
By releasing millions of specially bred sterile mosquitoes over the past two years, scientists in China have successfully contained the dengue menace in the country's most populous province, Guangdong, of which Guangzhou is the capital.
Renowned journal Nature carried an article on July 17 – “Incompatible and Sterile Insect Techniques Combined Eliminate Mosquitoes” – depicting science's success in eradicating dengue-causing mosquitoes in Guangdong, a province of 100 million people previously known for high rate of dengue prevalence.
The mastermind behind China’s SIT project, Xi Zhiyong, a microbiology professor at Guangzhou's Sun Yatsen University, and his team, declared that their effort to eradicate dengue by pitting sterile mosquitoes against the fertile ones had succeeded.
Dr Aftab told this correspondent on Saturday that AERE has a weekly capacity of producing 10,000 to 15,000 sterile mosquitoes now, but given the high density of mosquito population in Dhaka “it may require us to release 10 million sterile mosquitoes a week to have an impact on the aedes population.”
He emphasized on exhausting certain steps prior to moving in the direction of actual application. These steps include, among others, capacity building of the lab and its manpower, survey of mosquito population in dengue outbreak zones, and field trial of the sterile mosquitoes that they have bred.
Last year, Xi's team in China, in collaboration with local disease control and prevention centres, extended the release of male sterile mosquitoes from suburban areas to Guangzhou's old city centres, where dengue fever outbreaks had previously been reported.
Drones were used to release over a million specially bred mosquitoes in a certain part of the old city.
The Guangzhou mosquito factory, the largest such facility of its kind in the world, is capable of producing 10 million sterile mosquitoes a week.
Wolbachia, a bacterium, is used to make male mosquitoes sterile.
Research findings have shown the eggs produced by female mosquitoes mating with Wolbachia-infected male counterparts, who are infertile, never hatch, and that helps lead to reduce the mosquito population in the area.
Since 2016, some 200 million sterile mosquitoes have been released in Guangdong.