Dengue fever outbreak in the Pacific and Southeast Asia regions

Several Pacific Island and Southeast Asian countries are reporting increased dengue activity. 

The Cook Islands has been particularly affected, with more than 500 cases reported since the outbreak began on 22 May 2025. Dengue transmission remains active, and case numbers continue to rise. Health officials in the Cook Islands are closely monitoring the situation which involves two dengue virus types (DENV1 and DENV2).

Other Pacific countries reporting an increase in dengue cases include Samoa, American Samoa, Tuvalu, Nauru, and Kiribati.

Other South and Southeast Asian countries reporting an increase in dengue cases include Bangladesh, Cambodia, Indonesia, India, Malaysia, Timor-Leste, Thailand and Sri Lanka.

What is dengue fever?

Dengue is a viral infection that spreads from mosquitoes to people. It is more common in tropical and subtropical climates.  

Dengue can be life threatening and people who have previously been infected with dengue are at an increased risk of developing severe dengue if they contract the virus again.

See our advice, including advice on preventing Dengue fever here.

Before travelling in the Pacific and wider South/Southeast Asia regions

To avoid dengue while travelling to the Pacific, you need to take extra precautions.

• Prevent mosquito bites and know how you can protect yourself and your family from dengue.  See our advice on Mosquito-borne illness prevention.
• Familiarise yourself with our advice for staying healthy on your trip.
• Talk to your doctor about preventative measures against insect-borne illnesses like Dengue fever.
• Hospitals are likely to be under significant pressure due to the outbreak and New Zealanders travelling in the Pacific should take this into consideration and have a comprehensive travel insurance policy in place that includes provision for medical evacuation by air.

If you feel unwell 

If you are unwell during your trip to one of these countries, or in the first three weeks after your return from a country know to have dengue, seek immediate medical advice and tell the doctors about your travel. 

• Drink plenty of fluids.
• Use paracetamol for fever and pain. Avoid aspirin and ibuprofen, as they can increase the risk of bleeding from dengue infections. 

Find out more:

• See where current dengue outbreaks are
• Read the World Health Organization (WHO) advice on dengue.
• Travellers urged to be on alert for dengue with increased cases in the Pacific – Health New Zealand | Te Whatu Ora.