Tonga Declares Dengue Fever Outbreak
- The Ministry of Health in Tonga declared a dengue fever outbreak on April 16, 2026, following the confirmation of six cases of the virus across the country.
- Health officials have identified six confirmed cases and seven suspected cases.
- The Ministry of Health reported that the number of confirmed and suspected cases continues to rise in Tongatapu, Ha’apai, and ‘Eua.
The Ministry of Health in Tonga declared a dengue fever outbreak on April 16, 2026, following the confirmation of six cases of the virus across the country.
Health officials have identified six confirmed cases and seven suspected cases. The majority of these cases are located in Ha’apai, with patients ranging in age from 10 to 35 years.
The Ministry of Health reported that the number of confirmed and suspected cases continues to rise in Tongatapu, Ha’apai, and ‘Eua. Because the six confirmed cases show no evidence of linkage, officials stated this strongly indicates community transmission across these three island groups.
Transmission and Environmental Factors
Dengue fever is a contagious disease spread from person to person through the bites of infected mosquitoes. The primary vector responsible for spreading the virus is the Aedes aegypti mosquito, which can be identified by black and white markings on its legs.
The Ministry of Health noted that more cases are expected due to the presence of Aedes mosquitoes and current weather patterns. Ongoing rain and adverse weather conditions have created favorable breeding sites for these vectors.
This development follows earlier reports from April 14, 2026, which noted three confirmed locally acquired cases in Tongatapu. At that time, patients were reported as stable, with one discharged and two receiving home care.
Symptoms and Medical Guidance
Public health officials are urging the population to remain calm and seek early medical attention if symptoms develop. Common symptoms of dengue fever include:
- Sudden high fever
- Severe headaches
- Pain behind the eyes
- Joint and muscle pain
- Nausea and vomiting
- Swollen glands
- A rash that typically appears three to four days after the fever begins
The Ministry of Health warned that certain severe symptoms require immediate medical attention, specifically abdominal pain, bleeding gums, or vomiting blood and other forms of bleeding.
Prevention and Public Health Response
To prevent further spread, the public is urged to maintain cleanliness in households and communities. Specific preventative measures include eliminating mosquito breeding sites, using bed nets and mosquito repellents, and wearing protective clothing.
This outbreak follows a significant surge of dengue cases across the Pacific islands in 2025. In Tonga, a previous outbreak was declared on February 19, 2025, which resulted in 845 confirmed cases and three dengue-related deaths.
During the 2025 response, the Ministry of Health conducted a national review on May 6, 2025, with support from the World Health Organization (WHO) to identify challenges and corrective measures. This review involved health workers and officials across clinical services, surveillance, logistics, and risk communications.
Dr Ofa Tukia, Director of Public Health from Tonga’s Ministry of Health
The IAR was an important opportunity to take stock of what’s working, where we need to improve, and how You can strengthen our dengue response together
As part of the previous effort to enhance patient care, the WHO deployed a clinical management expert to Tonga on May 20, 2025, to assist local teams with the early identification of warning signs and the referral of severe cases.