Singapore ramps up ‘Wolbachia’ mosquito breeding as dengue crisis escalates

The city state will breed 5 million male Aedes mosquitoes a week instead of 2 million; carrying Wolbachia bacteria, when they mate with female urban mosquitoes the eggs that are laid do not hatch

There have already been 14,000 dengue fever cases this year in an earlier-than-usual surge, expected to escalate; other countries, including Malaysia and Thailand, are also seeing a spike in infections

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Mosquitoes can cause dengue, a viral disease which has spread around the world in recent years and is sometimes fatal. Photo: Shutterstock

Published: 5:00pm, 15 Jun 2022Updated: 5:52pm, 15 Jun 2022

Singapore will accelerate the production of its lab-grown male mosquitoes that are released into the community to suppress the mosquito population amid an alarming dengue outbreak in the tropical city state.

Minister for Sustainability and the Environment Grace Fu on Wednesday said some 5 million male Aedes mosquitoes would be manufactured each week, up from 2 million previously.

These specially-bred mosquitoes carry Wolbachia, a bacteria, so when they mate with female urban mosquitoes, their resultant eggs do not hatch. The goal is to eventually shrink the mosquito population and contain dengue, a mosquito-borne viral disease that has spread rapidly around the world in recent years.

Male ‘Wolbachia’ Aedes mosquitos being released in Singapore in 2020. The nation is to more than double its weekly release of the insects in the battle against dengue. Photo: Reuters

Singapore’s plans are part of an expansion of Project Wolbachia, which will, from July, cover 1,400 more public housing blocks (140,000 homes), in addition to the 1,800 blocks already included. About 31 per cent of public housing in the city state will at that point be in the programme, up from 19 per cent at the moment.

Fu, announcing the expansion at the Asia Dengue Summit in Singapore, pointed out that the global threat of dengue – typically a tropical disease carried by mosquitoes, which can sometimes be fatal – will continue to escalate. “The challenge we face is formidable,” she said, noting that urbanisation and climate change have created favourable conditions for mosquito breeding.

“Dengue and other mosquito-borne viruses are no longer just a problem of the tropics. Unconfined by borders or socioeconomic lines, they will challenge communities around the world.”

Male Aedes mosquitos carrying the Wolbachia bacteria are released on a housing estate test site in Singapore in 2020. Photo: Reuters

Several countries in Southeast Asia are already experiencing an uptick in dengue cases and taking precautionary measures. Malaysia has reported close to 12,000 cases this year as of May, a 35 per cent increase compared to the same time last year, according to WHO data.