Travellers returning to the United Kingdom are being urged to take extra precautions after a dramatic surge in cases of mosquito-borne viruses, most notably chikungunya, in the first half of 2025. According to the UK Health Security Agency (UKHSA), more than 70 cases of chikungunya were reported between January and June this year, more than double the 27 cases reported during the same period in 2024. All cases have been linked to travel abroad, especially to hotspots such as India, Sri Lanka, and Mauritius, and most were detected in London. The sudden uptick is raising alarms among health officials and holidaymakers alike, as similar outbreaks have swept across Asia, Africa, Europe, and the Americas this year.
Chikungunya, a virus transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes, is notorious for causing sudden fever and excruciating joint pain. While most people recover within a couple of weeks, some can experience lingering joint discomfort for months or even years. "Chikungunya can be a nasty disease and we're seeing a worrying increase in cases among travellers returning to the UK," warned Dr. Philip Veal, consultant in public health at UKHSA, in a statement quoted by BBC News. "It is essential to take precautions against mosquito bites when travelling. Simple steps, such as using insect repellent, covering up your skin and sleeping under insecticide-treated bed nets can greatly reduce the risk."
Despite the relatively small number of cases compared to the UK population, the doubling in infections is significant, especially as it mirrors a wider global pattern. In 2025 alone, approximately 240,000 cases and 90 deaths from chikungunya have been reported worldwide through July, spanning 16 countries and territories in the Americas, Africa, Asia, and Europe, according to Scientific American. Notably, an outbreak in southern China’s Guangdong province and the city of Foshan saw about 7,000 cases reported in just one week, prompting the U.S. Centers for Disease Control and Prevention to issue a travel warning for the region. Outbreaks have also been noted in the Indian Ocean islands of Reunion, Mayotte, and Mauritius, as well as in France and Italy.
Chikungunya gets its name from a Tanzanian word meaning “that which bends up,” a reference to the stooped posture sufferers often adopt due to severe joint pain. Other symptoms can include headaches, sensitivity to light, skin rashes, nausea, and fatigue. In rare cases, the virus can cause heart damage or prove fatal, particularly among the elderly, infants, or those with weakened immune systems. While the disease is rarely deadly, its impact on quality of life can be profound. "Most people recover fully within a couple of weeks, but for some, pain can persist for months or even years," the UKHSA noted in its latest travel-associated infections report.
Fortunately, the risk of onward transmission within the UK remains negligible. The two mosquito species responsible for transmitting chikungunya are not established in Britain, so there is no threat of the virus spreading from person to person or through local insect populations. As Dr. Robert Jones, an insect biologist at the London School of Hygiene & Tropical Medicine, explained to Scientific American, “Neither of these species is established in the U.K., so there is no risk of onward transmission.” However, the situation is different in parts of the United States, where both Aedes aegypti and Aedes albopictus are present, especially in southern and eastern states. As of this year, 47 cases have been confirmed in the U.S.
In response to the outbreaks, health authorities in affected regions have ramped up mosquito control efforts, distributing nets and spraying insecticide in residential areas, streets, and outdoor workplaces. There have even been reports from China of infected individuals being forced into hospitals, a reminder of the strict public health measures seen during the COVID-19 pandemic. The UKHSA, meanwhile, is focusing on prevention and education, urging travellers to check the Travel Health Pro website for the latest advice before departure and to consider vaccination when visiting high-risk regions.
"A chikungunya vaccine may also be considered for those travelling to higher-risk regions," Dr. Veal advised. Two vaccines, IXCHIQ and VIMKUNYA, are approved and available in the UK from private travel clinics. Both have been shown to lower the risk of infection by prompting the body to produce protective antibodies. Despite the availability of vaccines, there are no specific antiviral treatments for chikungunya; care is mainly supportive, focusing on hydration and pain management.
Adding to the concern, the UK has just recorded its first ever cases of Oropouche virus, another emerging threat spread predominantly by midge bites rather than mosquitoes. All three cases detected so far were linked to travel from Brazil. Oropouche virus, first identified in Trinidad and Tobago in the 1950s, has been mostly confined to the Amazon region but has recently spread to countries like the Dominican Republic, Cuba, and Peru. Symptoms include high fever, chills, headache, joint and muscle pain, nausea, and vomiting. Most recover on their own, but the illness can be severe in the very elderly or immunocompromised individuals. Pregnant travellers are being advised to take particular care due to concerns about the virus’s potential impact during pregnancy.
The UKHSA has also observed a rise in Oropouche virus infections globally since 2024, echoing the pattern seen with chikungunya. "Anyone who gets such symptoms after being in Central and South America or the Caribbean is advised to get urgent medical advice," the agency stated, as reported by Sky News. The World Health Organization notes that, prior to late 2023, Oropouche was mostly reported near the Amazon rainforest, but it has since spread across several South American countries.
Interestingly, while cases of chikungunya and Oropouche have increased, the UK saw a 67 percent decrease in dengue cases and only four cases of Zika virus reported in England, Wales, and Northern Ireland in the first half of the year, down from nine in 2024, according to The Independent. Cholera, however, saw a rise, with eight cases reported compared to just one last year, mostly linked to travel to India and Ethiopia.
For now, the message from health officials is clear: vigilance and prevention are key. Travellers should not only pack their passports but also insect repellent, protective clothing, and perhaps even consider vaccination before heading to tropical or subtropical regions. As Dr. Veal succinctly put it, “It is essential to take precautions against mosquito bites when travelling.” With outbreaks of mosquito- and midge-borne diseases on the rise worldwide, a little preparation could go a long way in ensuring a safe and healthy trip.
