Grown in a Lab, Released in the Wild: Laos Unleashes Over 130 Million Disease-Reducing Mosquitoes After Global Dengue Surge
VIENTIANE, (August 13, 2025) – More than 130 million disease-reducing mosquitoes are being released in Vientiane, the capital of Laos, after cases of dengue hit a record high globally in 2024 at over 14.4 million – more than double the previous record of 2023,[1] with children at greater risk of severe dengue illness.
The lab-grown mosquitoes carry a naturally occurring bacteria called Wolbachia, which reduces the insect's ability to transmit deadly viruses to people, decreasing the risk of dengue, Zika, chikungunya, and yellow fever outbreaks. When Wolbachia mosquitoes are released, they breed with wild mosquitoes until, over several generations, they replace the local mosquito population.
The Ministry of Health, Department of Communicable Disease Control and Save the Children International in Laos, with the support from the Government of Australia and World Mosquito Program, organised the Wolbachia mosquito release event as part of the project "Deployment of the WMP Wolbachia method to reduce dengue incidence in Lao PDR".
Speaking at the launch event, Baikham Khatthiya, Minister of Health, Lao People's Democratic Republic, said:
"The use of this new innovation in dengue control may be an effective way for us to control dengue disease. Therefore, on behalf of the leadership of the Ministry of Health, I call upon all relevant sectors to pay attention and actively contribute to the implementation of this project with the highest efficiency and effectiveness, so that it can serve as a model for expanding the project nationwide.
"I am confident that with the cooperation between the Ministry of Health, development partners, and all levels of local authorities in this implementation, we will certainly be able to achieve success."
Luke Ebbs, Country Director, Save the Children in Laos, said:
"As temperatures rise and warmer, wetter conditions fuel the spread of mosquito-borne diseases, these millions of mosquitoes will not only reduce the number of dengue cases – they will save lives.
"Dengue is a serious but preventable disease. It strains health systems during peaks of the disease and is especially dangerous for children. This innovative approach will help combat dengue not just now but also in the long term.
"Wolbachia mosquitoes have already shown remarkable success in combating dengue in cities around the world, from Brazil to Indonesia. We're hopeful we'll see similar life-saving results in Laos."
Megan Jones, Australian Ambassador to Lao PDR, said:
"Australia's support for the Driving Down Dengue program reflects our commitment to improving health outcomes in Laos and strengthening regional health security.
"We are also very proud that the technology enabling this program is Australian.
"This collaboration with the Ministry of Health, Save the Children, and World Mosquito Program showcases the power of innovation in tackling global health challenges."
Dengue is endemic in Laos, with cases increasing during the warmer and wetter months. More than 20,000 dengue cases and 11 deaths were recorded in 2024.
Siphat, 63, works as a village health volunteer in Vientiane Capital and was hospitalised for dengue.
Siphat said:
"I had a high temperature, headache and joint pains, but I didn't know why. I thought I'd recover quickly, but I didn't. I visited a clinic and tried to treat myself for four days, but I didn't get better. It was only when I went to the hospital that I found out I had dengue. I was in the hospital for 12 days."
The mosquitoes are bred in Australia, grown from eggs to adults in a laboratory in Laos, and then released into communities from reusable cups. By 2028, more than 1.2 million people in Laos will benefit from the Wolbachia mosquitoes.
Siphat added, "I think the Wolbachia project will yield good results, so I support it, and I'm happy because if mosquitoes bite us, it won't be severe. I think our community will get better, and our project should continuously improve and be promoted widely."
Data from the World Mosquito Program consistently shows major reductions in dengue after Wolbachia mosquitoes are introduced. Dengue transmission has been significantly reduced in North Queensland, Australia, due to sustained Wolbachia levels, and a trial in Yogyakarta, Indonesia, showed a 77% reduction in dengue cases compared with untreated areas.[2]
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Notes and references:
Save the Children has been supporting children and championing child rights in Laos since 1987. In 2024 alone, we directly supported over 270,000 children across the country. We aim to ensure that every child's right to health, education, protection, and participation is upheld, even in the face of disasters and the growing challenges of climate change.
The release of the mosquitoes in Vientiane - which will continue over the next 5 months – is the second phase of the joint venture, which aims to protect 1.2 million people in Laos from mosquito-borne diseases, including dengue, Zika and chikungunya, in four provinces and the capital city by 2028. The pilot project in 2023 covered 86,000 people and provided valuable research, allowing the World Mosquito Program to learn and adapt the project for this new phase.
The Wolbachia mosquitoes are only being introduced in areas where at least 60% of people agree to their release.
Global cases of dengue reached the highest number on record in 2024 at over 14.4 million – more than double the previous record of 2023. [1] Increased urbanisation and changes in climate and temperatures are fueling the spread of the disease. The World Health Organization estimates that 4 billion people are currently at risk of dengue and related viruses, and this will rise to 5 billion by 2050.[3]
[1] https://worldhealthorg.shinyapps.io/dengue_global/
[2] https://www.worldmosquitoprogram.org/en/work/wolbachia-method/impact#:~:text=In%20areas%20where%20Wolbachia%20is,Mathematical%20modelling
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