Key Summary
- UKHSA is reminding travellers to take precautions against infectious disease.
- 557 malaria cases were reported in England, Wales and Northern Ireland from January to May.
- Eight Zika virus cases were seen in the UK this year up to June.
The UK Health Security Agency (UKHSA) has reminded travellers to take precautions against travel-associated infections overseas.
UKHSA published provisional data for England, Wales and Northern Ireland on specific selected travel associated infections including mosquito-borne infections (dengue fever, Zika virus, chikungunya virus and malaria) and enteric fever (typhoid and paratyphoid fever).
The latest data for imported dengue fever shows that a total of 137 cases were reported in England from January to June 2026.
South-East Asia and South Asia remain the most common regions of exposure, with 27 cases linked to travel to Thailand and 19 to the Maldives.
A total of eight Zika virus cases were reported from January to June 2026. This already exceeds seven cases recorded in 2025. Indonesia was the most frequently reported country of exposure, accounting for four of eight cases in 2026 so far. Notably, only one travel-associated case linked to Indonesia had been reported between 2014 and 2025, which occurred in 2024.
A total of 59 chikungunya virus cases were reported from January to June 2026, with Sri Lanka being the most commonly reported country of travel, accounting for 18 cases.
Meanwhile, 557 malaria cases were reported in England, Wales and Northern Ireland from January to May 2026.
Malaria is potentially fatal but almost entirely preventable when antimalaria tablets are taken correctly.
The data showed that cases of dengue fever and Zika presenting through spring and into the summer, with dengue recording its highest 2026 monthly total in June, and Zika cases reported throughout this period.
In addition to mosquito-borne infections, a total of 287 travel-associated enteric fever cases (typhoid and paratyphoid fever) were reported from January to June 2026. These are serious but preventable illnesses caused by Salmonella bacteria, usually spread through contaminated food or water.
The highest number of enteric fever cases has been recorded between May and October in recent years, with September seeing a peak of 118 cases in 2025.
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.
Mosquito-borne infections can cause fever, headache, muscle and joint pain, nausea and vomiting, and can be serious, although some people experience no symptoms.
UKHSA reminded travellers to reduce their risk by avoiding mosquito bites (use insect repellent, cover exposed skin, sleep under treated nets when advised), maintaining food and water hygiene, and getting recommended vaccines and antimalarial medication before travel.
UKHSA also highlighted that measles continues to circulate in parts of the UK and overseas. Measles spreads easily and can cause serious complications; the best protection is two doses of MMR (or MMRV) vaccine. Babies under 12 months and some immunocompromised people cannot receive the vaccine and depend on high community vaccination coverage for protection.
Parents are urged to ensure children’s routine immunisations are up to date before travelling.
