HANOI, March 6 (Xinhua) -- Vietnam on Tuesday officially started releasing mosquitos laced with Wolbachia -- a common kind of bacteria capable of preventing Aedes aegypti mosquitoes from becoming infected with dengue virus, meaning that the mosquitoes cannot transmit the virus to humans.
Wolbachia-laced mosquitos were released for the first time in Vinh Luong commune, Nha Trang city, central Khanh Hoa province.
After the first release in Vinh Luong on Tuesday, some 100 Wolbachia-laced mosquitos will be released in the commune every week in the next 12-18 weeks, said Vietnam's National Institute of Hygiene and Epidemiology.
Earlier, a research group from the Hanoi-based institute and Australian scientists bred Aedes aegypti mosquitos laced with Wolbachia and then released them on a trial basis on Tri Nguyen island in Khanh Hoa in 2013 and 2014.
Since 2014, no dengue fever outbreaks have been detected on the island, while Nha Trang and Khanh Hoa have reported big outbreaks of the disease.
When male and female Aedes aegypti mosquitoes with Wolbachia are released over a number of weeks, they then breed with the wild mosquito population, passing the bacteria from generation to generation.
Over time, the percentage of mosquitoes carrying Wolbachia grows until it remains high without the need for further releases. Mosquitoes with Wolbachia are less able to transmit diseases to people, so the risk of outbreaks in these areas is reduced.
Vietnam, which spotted 175,800 dengue fever patients, including 38 fatalities, and 39 Zika sufferers last year, detected 8,000 cases of dengue fever in the first two months of this year, said the Preventive Medicine Department under the Vietnamese Ministry of Health.
Zika is a virus spread to humans by Aedes mosquitoes -- the same mosquitoes that spread dengue, chikungunya and yellow fever.