Dengue Fever Prevention and Safety: A Guide for UK Travellers

Dengue fever is a viral infection spread to humans through the bite of infected mosquitoes, primarily the Aedes aegypti and Aedes albopictus species. According to NHS guidance, it is most common in Southeast Asia, the Pacific Islands, Latin America, and parts of Africa. Unlike the mosquitoes that carry malaria, the Aedes mosquitoes are 'day-biters,' meaning they are most active during daylight hours, particularly two hours after sunrise and several hours before sunset.

For most UK travellers, Dengue results in a flu-like illness that resolves within a week. However, it is nicknamed 'breakbone fever' due to the intense muscle and joint pain it can cause. In a small percentage of cases, it can develop into severe Dengue (formerly known as Dengue Haemorrhagic Fever), which is life-threatening. As there is no specific antiviral treatment for Dengue, prevention is the cornerstone of travel safety.

Symptoms usually begin 4 to 10 days after being bitten. The primary indicator is a sudden, high temperature (39°C to 40°C). This is frequently accompanied by:

• Severe headache: Often described as pain behind the eyes.
• Muscle and joint pain: Which can be debilitating.
• Nausea and vomiting: Leads to a risk of dehydration.
• Swollen glands: Particularly in the neck and groin.
• Dengue rash: A flat, red rash that may appear over most of the body 2-5 days after the fever starts.

It is important to note that many of these symptoms overlap with other tropical diseases like malaria or Zika. If you develop a fever after returning from a tropical region, you should contact a healthcare professional immediately to rule out malaria, which requires specific urgent treatment.

Because Aedes mosquitoes thrive in urban environments and bite during the day, standard nighttime malaria precautions are not sufficient. To reduce your risk, follow these evidence-based steps:

1. Use Effective Insect Repellents

Use a repellent containing at least 50% DEET (diethyltoluamide). If you are sensitive to DEET, Icaridin (Picaridin) or oil of lemon eucalyptus are effective alternatives. Repellent should be reapplied frequently, especially if you are sweating or swimming.

2. Wear Protective Clothing

Cover as much skin as possible. Wear long-sleeved shirts, long trousers, socks, and a hat. Treating clothes with permethrin provides an extra layer of protection that lasts through several washes.

3. Manage Your Environment

Mosquitoes breed in stagnant water. Avoid staying near open water storage, flowerpots, or discarded tyres. Ensure your accommodation has intact window screens or air conditioning, which keeps mosquitoes out of the room.

In early 2023, the Joint Committee on Vaccination and Immunisation (JCVI) and the MHRA approved a new Dengue vaccine called Qdenga for use in the UK. Unlike previous vaccines, Qdenga can be given to individuals regardless of whether they have had a previous Dengue infection.

The vaccine is generally recommended for travellers aged four and older who are visiting high-risk areas for extended periods or those who have had Dengue before, as a second infection carries a higher risk of complications. It involves a two-dose schedule, usually spaced three months apart. You should speak to a GP or a travel health specialist at least four months before your trip to ensure you are fully protected.

There is no cure for Dengue; treatment focuses on managing symptoms while the body fights the virus. NICE guidelines suggest the following for mild cases:

• Hydration: Drink plenty of fluids (water, oral rehydration salts) to avoid dehydration caused by fever and vomiting.
• Pain Relief: Use paracetamol to manage fever and pain.
• Avoid Ibuprofen and Aspirin: This is a critical safety point. These anti-inflammatory drugs can increase the risk of bleeding, which is dangerous if you have Dengue.
• Rest: Allow your body time to recover.

If symptoms worsen or you feel a sudden 'crash' just as the fever seems to be breaking, seek local emergency medical help immediately.

Careful preparation is vital for any trip to the tropics. You may want to speak to a GP online if:

• You need to discuss whether the Dengue vaccine is appropriate for your specific destination and medical history.
• You require advice on assembling a travel health kit, including appropriate sunscreens and repellents.
• You are currently abroad and have developed mild symptoms but are unsure how to manage them safely.
• You have recently returned to the UK and feel unwell with a lingering headache or joint pain.

An online GP can provide a private consultation to review your itinerary, discuss bite-prevention strategies, and, if necessary, provide private prescriptions for other travel-related medications like antimalarials or altitude sickness tablets.