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Dengue alert updated: twelve countries with unusually high cases, plus Cuba

Qurexa Editorial Team5 September 20266 min read 0 0
Dengue alert updated: twelve countries with unusually high cases, plus Cuba

What happened

The US Centers for Disease Control and Prevention updated its global dengue travel health notice on 3 September 2026. The notice sits at Level 1, meaning travellers should practise usual precautions. It is a standing alert rather than an emergency, first posted in June 2024 and refreshed as the picture changes. The update names twelve places currently reporting higher than usual numbers of cases: Bangladesh, Bolivia, Cambodia, Colombia, Costa Rica, Kenya, Malaysia, Maldives, Marshall Islands, Sri Lanka, Vanuatu and Vietnam. Separately, CDC's dengue risk information records that as of 2 September 2026, Cuba met the criteria for high transmission and had 10 or more cases reported among travellers in the previous three months. That list will catch the eye of British travellers. The Maldives, Sri Lanka, Vietnam, Malaysia, Cambodia and Cuba are all popular destinations for UK holidaymakers, particularly in the autumn and winter months when people escape the British weather. The CDC notes that dengue is a year-round risk in many parts of the world, and that outbreaks tend to happen every two to five years.

Why this matters

Dengue is the most common mosquito-borne viral illness affecting travellers, and it is becoming more common rather than less. For most people who catch it, the illness is unpleasant but short. The UK's National Travel Health Network and Centre notes that between 40 and 80 per cent of people infected have no symptoms at all. When symptoms do appear, they usually start five to eight days after the bite. A high fever, up to 40 degrees, is typical, often with a severe headache, and pain in the muscles and joints. A rash may show up around day three or four. The illness generally lasts under a week. Severe dengue is rare in travellers, but it is a medical emergency. It can involve bleeding, shock and organ failure, and it needs hospital treatment. There is one point every traveller should understand, because it is counter-intuitive. There are four subtypes of dengue virus. Catching one gives you lasting protection against that subtype, but being infected a second time with a different subtype carries a greater risk of severe illness. So a previous bout of dengue is not a reason to relax. If anything it is a reason to be more careful. Higher-risk groups include children, pregnant women, older adults, and people with conditions such as diabetes or asthma.

What the evidence actually says

A Level 1 notice is the lowest of the CDC's categories. It is not a warning to cancel a holiday. It is a prompt to take ordinary precautions seriously. It is also worth understanding how these lists are compiled. The countries named are those reporting higher than usual case numbers, and CDC's traveller thresholds are partly based on cases reported among returning American travellers. A country not on the list is not necessarily dengue-free. Many places carry a steady year-round risk without appearing on any alert. On vaccination, UK travellers need to be careful about what they read online, because the position here is narrower than in some countries. A dengue vaccine called Qdenga is licensed in the UK for people aged four and over. But UK travel health guidance currently recommends it only for people who have had dengue before and are travelling to areas where it is endemic, or who are exposed through their work. The reasoning goes back to the point about subtypes. In someone who has never had dengue, vaccination can, in some circumstances, carry its own risks. That is why UK advice is restrictive, and why this is a decision for a travel clinic rather than a website. There is no antiviral treatment for dengue. Care is supportive, meaning fluids, rest and monitoring. NaTHNaC notes that antiviral and steroid treatments have not been shown to help recovery. So for the overwhelming majority of UK travellers, protection comes down to one thing: not getting bitten.

Practical advice

Bite avoidance is unglamorous and it works. Here is how to do it properly. Use an effective insect repellent on exposed skin and reapply it as often as the label says, especially after swimming or sweating. Apply sunscreen first and repellent second. Cover up where you can. Loose, long-sleeved tops and long trousers give real protection, and are more comfortable in heat than people expect. UK guidance highlights that the mosquitoes that spread dengue feed most actively around dawn and dusk, so be especially careful at those times. Do not assume you are safe in daylight. Sleep in a room with air conditioning or screens on the windows, or use a mosquito net. Get rid of standing water near where you are staying. Buckets, plant saucers, unused paddling pools and blocked gutters are breeding sites, and these mosquitoes do not travel far from where they hatch. Before you go, book a travel health appointment six to eight weeks ahead. Ask about dengue, but also about everything else relevant to your destination, including malaria, which needs a completely different approach. If you have had dengue before, say so at that appointment. It changes the advice. After you return, take a fever seriously. If you develop a high temperature within two weeks of coming home from an affected area, contact your GP or NHS 111 and tell them where you have been. If you have severe abdominal pain, persistent vomiting, bleeding gums or nosebleeds, or you feel very unwell and are getting worse, seek urgent medical help.

What to know

CDC updated its global dengue travel health notice on 3 September 2026, listing twelve places with higher than usual case numbers: Bangladesh, Bolivia, Cambodia, Colombia, Costa Rica, Kenya, Malaysia, Maldives, Marshall Islands, Sri Lanka, Vanuatu and Vietnam. CDC separately recorded Cuba as meeting high transmission criteria as of 2 September 2026, with 10 or more cases among travellers in the previous three months. Between 40 and 80 per cent of people infected have no symptoms. Those who do typically get a high fever, severe headache and muscle and joint pain five to eight days after being bitten. A second infection with a different dengue subtype carries a greater risk of severe illness, so a previous case is a reason for more caution, not less. The Qdenga vaccine is licensed in the UK from age four, but UK guidance currently recommends it only for people with previous dengue infection travelling to endemic areas, or those exposed at work. There is no antiviral cure. Bite avoidance is the main protection, and it also guards against chikungunya and Zika. A fever within two weeks of returning from an affected area should be checked, and you should always mention your travel. Sources: US Centers for Disease Control and Prevention, "Global Dengue - Level 1 - Practice Usual Precautions", updated 3 September 2026, https://wwwnc.cdc.gov/travel/notices/level1/dengue-global | US Centers for Disease Control and Prevention, "Areas with Risk of Dengue", accessed September 2026, https://www.cdc.gov/dengue/areas-with-risk/index.html | NaTHNaC / TravelHealthPro, "Dengue" factsheet, last updated 2 June 2026, https://travelhealthpro.org.uk/factsheets/dengue This article is for general information and does not replace advice from a doctor, pharmacist, travel health clinic or other qualified healthcare professional. Vaccine suitability depends on your circumstances. If you become unwell with a fever after travelling, seek medical advice and tell them where you have been.

#dengue#travel health#mosquito bites#travel vaccines#autumn holidays#returning travellers

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