The UK Health Security Agency (UKHSA) has issued a warning to holidaymakers about the risks of mosquito-borne diseases, as new data shows an increase in imported infections. The agency urged travelers to take precautions, including using insect repellent, wearing long sleeves and trousers, and sleeping under treated bed nets.
Rising Cases of Zika and Dengue
From January to June 2026, eight cases of Zika virus were reported in England, already surpassing the seven cases recorded in all of 2025. Four of these cases were linked to travel to Indonesia. Additionally, 137 cases of imported dengue were reported in the same period, with South-East Asia and South Asia being the most common regions of infection. Thailand accounted for 27 cases and the Maldives for 19.
For comparison, the total number of dengue cases by the end of June 2025 was 161, though cases typically increase later in the year. Chikungunya cases reached 59 from January to June 2026, with Sri Lanka being the most commonly reported country of travel (18 cases). This is down from 73 cases in the same period last year.
Malaria and Other Infections
From January to May 2026, 557 malaria cases were reported in England, Wales, and Northern Ireland, compared to 548 in the same period last year. Malaria can be fatal, with symptoms including fever, vomiting, and pain. Additionally, 287 cases of typhoid and paratyphoid fever were reported between January and June 2026, caused by Salmonella bacteria spread through contaminated food or water.
Dr Hilary Kirkbride, consultant epidemiologist and head of travel health at UKHSA, said: “Summer is a popular time to travel – don’t let illness spoil your holidays. Good preparation and planning is important for a safe and enjoyable trip. Check the TravelHealthPro website for the latest health advice for your destination, including which vaccines you may need and any important medications, such as anti-malarial tablets.”
Precautions for Pregnant Women
Zika virus is particularly dangerous for pregnant women, as it can cause stillbirth, miscarriage, and birth defects such as microcephaly. Dr Kirkbride added: “If you are pregnant or trying to conceive, there are special precautions you should take, so please speak to a doctor, nurse or local travel clinic before planning your trip.”
Natalie Hitchins, Which? head of home products and services, advised travelers to choose effective insect repellents: “Which? tests found that while some repellents provided effective protection for almost 10 hours, some trendy alternatives failed to prevent bites for longer than a few minutes. Look for products containing active ingredients such as Deet, Icaridin (picaridin) or PMD, rather than relying on marketing claims alone.”
Importance of Vaccinations
Travelers are reminded to get any necessary jabs and check if they need malaria tablets. Insect repellent should be used alongside, not as a replacement for, vaccinations or medications recommended by a healthcare professional. Mosquitoes breed in standing water and require warm temperatures to hatch, which can take just a few days in hot conditions.
