Joint News Release by WHO and Tonga Ministry of Health
Dengue cases have increased significantly across the Pacific islands in 2025, including in Tonga, where this mosquito-transmitted illness continues to spread. Since the outbreak was declared on 19 February, Tonga, a country with just over 100 000 people, has recorded 845 confirmed cases and 3 dengue-related deaths. Cases have been reported on 4 main islands, with the highest numbers in Vava’u and Tongatapu, which includes the capital, Nuku‘alofa.
The Ministry of Health has been promptly responding to the outbreak. After 3 deaths, the Ministry conducted a national review that aimed to identify best practices, challenges, lessons learned, and to propose corrective measures in the outbreak response on 6 May, with support from WHO.
The Intra-Action Review (IAR) brought together health workers and officials from management, logistics, finance, administration, clinical services, surveillance, environmental health, and risk communications and community engagement.
“The IAR was an important opportunity to take stock of what’s working, where we need to improve, and how we can strengthen our dengue response together,” said Dr Ofa Tukia, Director of Public Health from Tonga’s Ministry of Health. As a result of IAR, Tonga is taking decisive actions to limit the spread of the virus and protect communities across the country – here is how:
Hands on patient care
Dengue has no specific cure, but early detection and good supportive care can make all the difference in saving lives during an outbreak. That’s why understanding how patients are assessed, treated, and monitored, especially those with severe symptoms, help them recover safely.
To support this effort, WHO deployed a clinical management expert to Tonga on 20 May. The expert worked with local health teams to enhance patient care, focusing on early identification of warning signs, effective symptom management, and quick referral of severe cases.
At Vaiola Hospital, staff received training and on-the-job mentoring to improve their triage processes and deliver timely care. Tonga is implementing a strategy aimed at achieving zero preventable deaths due to dengue. The training will be conducted in the outer islands using a ”Training of trainers model” supported by online mentoring.
Tracking the disease through effective surveillance
To combat dengue effectively, the Ministry of Health and WHO are also working together to improve the reporting and tracking of dengue cases, with an emphasis on early recognition of severe dengue warning signs.
An updated surveillance plan is now being put into action. It brings together data from local health clinics, hospitals, and laboratories to better understand the scale of the outbreak, to assess the extent and severity of dengue, map high-risk areas, and guide more targeted dengue prevention and control efforts across Tonga.
Stopping dengue at its source through controlling the breeding of mosquitos
Controlling mosquito numbers has been another component of Tonga’s dengue response. To achieve this goal, the government reduces the breeding sites and provides treatments with larvicides. WHO has sent supplies like larvicides, insecticides, and repellents to Tonga. Field teams monitor the situation to assess and adjust the response as needed.
Empowering communities with knowledge and tools for action
In any dengue outbreak, timely and accurate information paired with strong community engagement can save lives. That’s why the Ministry of Health, in partnership with WHO, has been sharing practical messages including on severe dengue and early warning signs widely through radio, TV, SMS, posters, and village outreach. Following the IAR, new targeted materials including on early detection were developed in both English and Tongan.
Alongside these efforts, health workers and outreach teams have been visiting villages to talk about how to protect themselves and eliminate mosquito breeding sites. Community clean-up actions such as removing standing water from old tires or containers are essential to reducing the number of mosquitoes that spread dengue.
“By taking these simple but powerful steps, communities play a direct role in preventing new infections and protecting themselves,” said Dr Anup Gurung, WHO Country Liaison Officer to Tonga. “We will continue working closely with Tonga to empower local communities and frontline health workers with tools, knowledge, and supplies driving an effective dengue response,” he continued.
Tonga’s early activation of emergency systems, strong government leadership, and coordination with WHO and partners are all helping to contain the outbreak. Continued focus on early detection, strong clinical care, community-led action and coordinated efforts are key to bringing dengue under control.
Media Contacts
Ms Lenka Dojcanova
Risk Communications Officer
WHO Regional Office for the Western Pacific - Division of Pacific Technical Support
Mobile: +679 777 9718
Email: dojcanoval@who.int
Dr Ofa Tukia
Director of Public Health
Tonga’s Ministry of Health
Email: o.tukia@gmail.com