The US CDC's 23 June 2026 global dengue notice flags 11 countries, from Bolivia to Timor-Leste. Here is what the list means and how to travel prepared.
CDC just flagged 11 countries for dengue. Here's where to pack smart
On 23 June 2026, the US Centers for Disease Control and Prevention refreshed its global dengue travel notice. Eleven countries made the list: Bolivia, Cambodia, Colombia, Guyana, the Maldives, Mali, New Caledonia, Samoa, Timor-Leste, Tonga, and Vietnam.
That is the same level of alert the notice has carried for most of the past five years. The CDC's "Level 1 — Practice Usual Precautions" is the lowest of its three travel notice tiers. It is a routine annual refresh, not a fresh emergency.
What it does, however, is give every traveller leaving for a tropical destination this summer a clean, current list of where dengue is actively circulating — and that list is worth a minute of attention before you pack.
What "Level 1" actually means
CDC's travel notice system runs from Level 1 (low) through Level 2 (intermediate) to Level 3 (avoid non-essential travel). A Level 1 notice says, in the CDC's own words, that travellers should "practice usual precautions" for the destination. It is not a travel ban. It is not a recommendation to cancel a trip. It is a heads-up that the destination has elevated dengue activity and that the standard advice — use repellent, cover up, sleep screened — applies with more force.
The 23 June refresh is the global Level 1 notice, which covers countries with sustained transmission. The more urgent Level 2 notices — for active outbreaks — sit on a separate page and currently cover a different set of countries for chikungunya, including French Guiana, Mauritius, Mayotte, Suriname, Bolivia, and the Seychelles.
The 11 countries, by region
- South America: Bolivia, Colombia, Guyana
- South-East Asia: Cambodia, Timor-Leste, Vietnam
- South Asia and the Indian Ocean: the Maldives
- West Africa: Mali
- Pacific: New Caledonia, Samoa, Tonga
The mix tells its own story. Dengue is no longer a single regional disease. It is now a year-round presence across the tropical band, with the highest transmission intensities shifting around the planet as new Aedes aegypti and Aedes albopictus populations establish themselves. Vietnam and Cambodia are the two countries that have carried the heaviest dengue burdens in South-East Asia in recent years. Bolivia, Colombia, and Guyana reflect the steady expansion of dengue in the Americas since the 2023 record year. The Pacific island entries — New Caledonia, Samoa, Tonga — point to the increasing burden on small island health systems, where a single bad outbreak can overwhelm a national hospital.
What the numbers behind the notice look like
The global dengue picture is large and structural. The World Health Organization estimates that 5.6 billion people live in areas at risk of dengue transmission, and that between 100 million and 400 million infections occur worldwide each year. Outbreaks typically cycle every 2 to 5 years in any given country as population immunity to the dominant serotype wanes and a new serotype takes over.
Severe dengue — the form that can progress to haemorrhage, shock, organ failure, and death — is rare in first infections and more common in second infections with a different serotype. That detail matters for travellers, because a northern-hemisphere adult who had an asymptomatic or mild primary infection in childhood can develop severe dengue on a second infection decades later, in any country where dengue circulates. The risk is small. It is not zero.
What the notice tells you to do
The CDC's recommendations for Level 1 destinations are the standard dengue prevention package.
Use an EPA-registered repellent on exposed skin during the day and evening. Dengue mosquitoes — primarily Aedes aegypti and, in some settings, Aedes albopictus — bite during the day, with peak activity in the early morning and late afternoon. This is the single most important point: dengue is not a dusk-and-dawn disease. The advice that covers malaria ("use your net at night") does not fully cover dengue.
Wear long sleeves and long trousers when practical, particularly in the early morning and late afternoon. Treat clothing with permethrin if you are spending extended time outdoors.
Sleep in air-conditioned or screened accommodation where possible. The mosquito is small enough to fit through standard window screens; check that screens are intact and that doors close flush.
The CDC does not currently recommend a dengue vaccine for the average short-stay traveller. The two licensed vaccines — Qdenga (TAK-003) and Dengvaxia — have specific eligibility criteria (age, prior infection status, length of stay) that make them appropriate for some travellers and inappropriate for others. Anyone considering vaccination for travel should consult a travel medicine specialist, ideally 4–6 weeks before departure.
What to watch next
The Level 1 notice is a moving document. The CDC reviews it on a rolling basis; countries are added when transmission increases and removed when it subsides. The 23 June refresh is the formal mid-year reset. Expect a small number of changes over the northern-hemisphere summer as South-East Asia moves deeper into its monsoon transmission peak and as the South American countries enter their spring transition.
The other two documents to read alongside the Level 1 notice are the active Level 2 chikungunya notices (currently French Guiana, Mauritius, Mayotte, Suriname, Bolivia, the Seychelles) and the ECDC Communicable Disease Threats Report (CDTR) weekly bulletin, which tracks autochthonous transmission in Europe. There is no European country on the CDC Level 1 dengue list. The European story is autochthonous transmission in the Mediterranean summer, which the ECDC bulletin covers separately.
What we know
- On 23 June 2026, the US Centers for Disease Control and Prevention reviewed and refreshed its global dengue Level 1 travel notice, listing 11 destinations with elevated dengue activity: Bolivia, Cambodia, Colombia, Guyana, the Maldives, Mali, New Caledonia, Samoa, Timor-Leste, Tonga, and Vietnam. (CDC)
- Level 1 is the lowest of three CDC travel notice tiers, indicating that travellers should "practice usual precautions" — use EPA-registered repellent, wear protective clothing, and sleep in screened or air-conditioned rooms. (CDC)
- Severe dengue can develop within hours of first symptoms, can require hospitalisation, and carries risks of haemorrhage, shock, organ failure, and death. The risk of severe dengue is higher in second infections with a different serotype. (CDC)
- The World Health Organization estimates that 5.6 billion people live in areas at risk of dengue transmission, with 100 to 400 million infections occurring globally each year. (WHO)
- Dengue is transmitted primarily by Aedes aegypti and Aedes albopictus, both of which bite during the day, with peak activity in the early morning and late afternoon. (CDC)
Sources cited
- US Centers for Disease Control and Prevention. "Dengue Worldwide — Level 1, Practice Usual Precautions." CDC Travel Notices, reviewed 23 June 2026. https://wwwnc.cdc.gov/travel/notices/level1/dengue-global
- US Centers for Disease Control and Prevention. "Travel Notices." CDC, snapshot 24 June 2026. https://wwwnc.cdc.gov/travel/notices
- World Health Organization. "World Dengue Day 2026 — Singapore." WHO, 15 June 2026. https://www.who.int/news-room/events/detail/2026/06/15/default-calendar/world-dengue-day-2026