People returning from holidays are being advised to take precautions against giardiasis, a parasitic stomach bug, following a 10 per cent annual surge in infections. The UK Health Security Agency (UKHSA) recorded 6,069 cases in 2025, an increase from 5,450 in 2024, marking the highest total since 2016.
Officials from the UKHSA suggest that the 11.4 per cent rise in cases may be influenced by factors such as post-pandemic travel, climate change, or enhanced testing methods. The parasite, which can be contracted both in the UK and abroad, spreads through contaminated food or water, direct contact with infected individuals or animals, and can also be sexually transmitted.
Nicola Love, senior food safety surveillance lead at UKHSA, stated that symptoms can persist for weeks to several months and, if left untreated, can lead to serious complications, particularly in young children, the elderly, and those with compromised immune systems. Infections are being observed in individuals returning from Southern Asia, South-Eastern Asia, Africa, and South America.
The UKHSA advises travellers to drink bottled water and consume cooked food, avoiding raw items like salads washed in tap water. Additionally, people are recommended to avoid swimming in rivers, lakes, or the sea when abroad. Good hygiene practices, such as washing hands with soap and water after using the toilet, changing nappies, and before preparing food, are also encouraged.