NEW data from the UK Health Security Agency (UKHSA) reveal that imported dengue cases in England, Wales, and Northern Ireland have reached their highest level since surveillance began in 2009, with all cases linked to travel abroad.
In 2024, a total of 904 dengue cases were reported among returning travellers, a significant rise from 631 cases in 2023. Most infections were associated with travel to Southern and South-Eastern Asia. UKHSA is strengthening its surveillance efforts to better understand where travellers are acquiring infections and what mosquito bite precautions they are using. This research aims to inform future public health interventions. The increase in dengue cases aligns with global trends, with the World Health Organization (WHO) reporting a post-pandemic rise in both dengue cases and deaths in 2023. Climate change, shifting mosquito distributions, and extreme weather events such as rising temperatures and heavy rainfall are key factors driving this surge.
In addition to dengue, other mosquito-borne infections have also increased. Imported cases of chikungunya more than doubled from 45 in 2023 to 112 in 2024, with most linked to travel in Southern Asia. Zika virus cases also rose from 8 in 2023 to 16 in 2024, predominantly among travellers returning from South-Eastern Asia. Although Zika is rarely severe, it poses a significant risk to pregnant women as it can be transmitted to the foetus. The Joint Committee on Vaccination and Immunisation (JCVI) has recommended dengue vaccination for some travellers, but there are no vaccines available for chikungunya or Zika, making mosquito bite prevention crucial.
Clinicians are urged to remind travellers of the importance of mosquito bite precautions, including using insect repellent, covering exposed skin, and sleeping under insecticide-treated bed nets. UKHSA advises all travellers to check the TravelHealthPro website for destination-specific health advice, including recommended vaccinations and malaria prevention measures.
Ada Enesco, EMJ
Reference
GOV.UK. Imported dengue cases reach record high. Available at: https://www.gov.uk/government/news/imported-dengue-cases-reach-record-high. 2025. Last accessed: 28 March 2025.
