Current dengue outbreak in Timor-Leste
According to WHO, more than 2000 cases of dengue fever were reported during February 2026. Heavily impacted areas included Becora, Formosa and Vera Cruz.
The rainy season for Timor-Leste (December- April) provides ideal conditions for mosquito breeding sites. In late February 2026, Dili and surrounding areas experienced significant flooding.
A similar large outbreak was experienced in 2022 with almost 4,000 cases. The outbreak peaked between January and May of that year.
Dengue risk in Dili
An interesting study of dengue risk in Dili was presented in 2023 as part fulfillment of an MSc in Tropical Health Innovation. Two administrative posts were identified as very high risk and high risk (Dom Aleixo and Cristo Rei). It highlights the urban nature of dengue fever.
Risk was based on several variables which included:
- Family knowledge of dengue including prevention and treatment
- Artificial containers (breeding sites)
- Household numbers
- Density of residential population
- Improper water drainage
- Natural water resources
About Dengue Fever
Dengue fever is a vector-borne disease. The virus is transmitted to humans by a mosquito bite. Humans are the only known reservoir of infection.
Outbreaks of dengue are not uncommon in the months following peak wet season.
Residual water in an urban environment provides good breeding sites (empty rubbish cans, pot plant saucers and ponds) for the mainly urban mosquito, aedes aegypti.
Public health interventions are mostly aimed at communicating mosquito avoidance health messages to individuals at risk (including travellers) and reducing breeding sites at a local level.
Advice for travellers
Travellers should be reminded of the risk of dengue fever and other mosquito-borne diseases when travelling to areas of risk. This may even include northern Australia.
More than 1,800 cases of dengue fever have been reported in Australia over the past 12 months (to February 15, 2026). Most of these cases are most likely short-term travellers returning from Indonesia and other countries in Asia and the pacific.
Dengue fever is also being reported across the wider region including Sri Lanka, where more than 13,000 cases have been reported in the first two months of 2026. See Sri Lanka dengue fever update.
Personal protective measures remain the most important way to reduce the risk of dengue fever. These include the use of insect repellents containing DEET or Picaridin, wearing protective clothing and sleeping under mosquito nets. For more detailed information, see mosquito avoidance measures.
Dengue Vaccine (Qdenga)
A vaccine for dengue (Qdenga) is currently available in the European Union, UK, Indonesia, Brazil, Argentina, Indonesia, Colombia and Thailand. It is not available in the USA or Australia (March 2026). Regulatory approval was sought in Australia in early 2025.
It may be available under the special access scheme in Australia. An approval letter from the TGA (Therapeutics Goods Administration) is required before the vaccine may be assessed. We await their decision on registration and indication for use.
Qdenga is a live attenuated vaccine.
It is given in a 2-dose schedule with a 3-month interval. Protection is present from 14 days. The length of protection is yet to be defined but likely more than 4 years.
According to WHO's expert committee on vaccines:
- The vaccine might be considered in settings with a high dengue burden and high transmission to maximise the public health impact.
- It should be introduced to children aged 6 to 16 years.
