Health agencies in both the United States and the United Kingdom are alerting the public to a significant increase in Cyclospora infections, an illness causing debilitating diarrhea, with many cases linked to recent travel to Mexico.
In the United States, over 18,000 cases have been reported across 45 states since the beginning of an outbreak, the source of which remains unidentified. No deaths have been attributed to the parasite.
The UK Health Security Agency (UKHSA) has recorded 67 cases since April, with a substantial number of those infected being travelers returning from Mexico. Between April 30 and July 15, 2026, the UKHSA reported 30 cases in England, 27 in Scotland, and 10 in Wales. Of the cases with available travel information, 48 individuals had visited Mexico, many specifying stays in the Riviera Maya or Cancun areas.
Cyclospora is caused by a microscopic parasite that can contaminate food, particularly fresh produce like salads, herbs, and soft fruits. The parasite does not naturally occur in the UK, and health officials emphasize there is no risk of person-to-person transmission. Affected individuals in the UK reported staying in various hotels and consuming food and beverages within all-inclusive resort packages.
Ongoing investigations are monitoring the situation. To mitigate the risk of infection, health experts advise travelers to practice good food and water hygiene. This includes drinking bottled water and ensuring all food is thoroughly cooked, even when staying in high-end resorts. Additionally, it is recommended to avoid uncooked berries, fresh herbs, unpeeled fruits, and salads when traveling to affected regions.