A decade after its inception, Project Wolbachia has expanded to cover more than half of Singapore’s households, marking a significant milestone in the city-state’s fight against dengue fever. The initiative, which uses lab-grown male mosquitoes infected with Wolbachia bacteria to suppress the population of the Aedes aegypti mosquito, now reaches over 840,000 homes or about 53% of all households, according to Senior Minister of State for Sustainability and the Environment Janil Puthucheary.
The announcement was made on October 31 during a 10th-anniversary event held at Our Tampines Hub. Project Wolbachia was first launched in 2016 with a pilot in Ang Mo Kio and aims to reduce dengue transmission by releasing male mosquitoes infected with Wolbachia, whose mating with wild females results in eggs that do not hatch. The method targets the Aedes aegypti species, known for transmitting dengue, Zika, and chikungunya viruses.
Research published earlier this year in the New England Journal of Medicine showed that in areas under the project, the Aedes aegypti population dropped by 80 to 90%, while the dengue risk for residents fell by more than 70%. Correspondingly, reported dengue cases in Singapore have sharply declined, reaching a seven-year low of 4,036 cases in 2025—down 70% from 13,651 cases in 2024.
Despite initial apprehension among residents, local community leaders like Lee Tee Loon, chairman of the Citizens’ Consultative Committee in Braddell Heights, one of the first zones covered by Wolbachia, said acceptance has grown over time as people saw the benefits in reducing dengue risks.
Janil Puthucheary emphasized that the initiative is not a complete solution and stressed the importance of maintaining good mosquito control practices. “Dengue prevention remains a shared responsibility,” he said, urging continued efforts to eliminate stagnant water where mosquitoes breed and maintain clean environments.
Looking ahead, the National Environment Agency (NEA) is evaluating current epidemiological data before deciding on further expansion of the program, according to Ng Lee Ching, group director of NEA’s Environmental Health Institute.
At the event, NEA also introduced a children’s book, "Kai’s Tiny Adventure with Wozzie," designed to educate young readers on science behind the initiative and encourage community participation in dengue prevention.
Dengue cases reported in 2026 continue to trend downward, with 2,564 cases recorded through the first three quarters—a 25% decrease compared to the same period last year. However, there was a notable spike in cases during the third quarter, with 1,384 infections reported between July and September, nearly double the 770 cases from April to June. There was one dengue-related death in the third quarter, bringing the year’s total to three fatalities.
The rising cases coincided with a shift in the predominant dengue virus serotype from DENV-2 to DENV-3, which now accounts for 45.9% of infections. Such serotype switches often lead to surges due to lower population immunity to the new strain.
Ng pointed out that the increase occurred during Singapore’s peak dengue season, typically from May to October, when warmer weather accelerates mosquito breeding. She also cited the ongoing El Niño climate phenomenon as a factor intensifying the outbreak risk. El Niño’s associated hotter and drier conditions can quicken the mosquito life cycle, further facilitating disease transmission.
Raman Veluchu, deputy chair of NEA’s dengue expert advisory panel, noted that global dengue cases have generally been declining, with approximately two million cases reported worldwide in 2026 so far—a drop from 14 million in 2024. However, he warned that climate change and El Niño-related weather patterns could fuel increases in dengue incidence next year, both globally and in Singapore. Raman, formerly with the World Health Organization’s Global Neglected Tropical Diseases Programme, stressed the need for sustained vigilance in dengue control measures moving forward.