The UK Health Security Agency (UKHSA) has warned Brits travelling abroad to take extra precautions after a surge in cases of the parasitic stomach bug giardiasis. Infections rose by more than 10 per cent in a year, reaching 6,069 cases in 2025 – the highest since 2016 and up from 5,450 a year earlier.
Rise linked to travel, climate and testing
Officials said the 11.4 per cent annual rise may be linked to increased travel since the pandemic, climate change, or better testing. According to UKHSA, infections are being seen in people returning from Southern Asia, South-Eastern Asia, Africa and South America.
Nicola Love, senior food safety surveillance lead at UKHSA, said: “We are seeing a rise in giardiasis in the UK.
“Symptoms can last from weeks to several months and if left untreated, it can cause serious complications especially in young children, the elderly and those with weakened immune systems.”
Symptoms and how it spreads
Giardia infection can be picked up in the UK as well as overseas, and is spread by consuming contaminated food or water, or through direct contact with infected people or animals. It can also be sexually transmitted.
Symptoms include diarrhoea, bloating, burping, wind and weight loss. In rare untreated cases, children with the infection can suffer malnutrition and stunted growth.
Precautions for travellers
Those travelling to affected areas should drink bottled water and eat cooked food rather than raw items, such as salads that have been washed in tap water. The UKHSA also advised people to avoid swimming in rivers, lakes or the sea when abroad.
Ms Love said: “There are some simple precautions everyone can take to reduce their risk, whether you are planning an autumn getaway somewhere warm or staying in the UK.
“Good hygiene can help prevent giardiasis and other common gastro illnesses. Wash your hands with soap and water after using the toilet, after changing nappies, and before preparing food.
“Encourage children to wash their hands regularly too. If you have a giardia infection, continue to hydrate yourself and see your GP – do not go swimming until two weeks after your diarrhoea has stopped.
“Parents should contact their GP or NHS 111 if they or their children are ill with dehydration, or if diarrhoea worsens or lasts longer than three days.”
