Holidaymakers are being warned after health officials reported a serious stomach illness in four European countries. A total of 133 cases have been found, with many hospitalised with diarrhoea, abdominal pain, nausea, vomiting and fever.

The European Centre for Disease Prevention and Control said the outbreak of Yersinia enterocolitica has been detected in France, Belgium, Luxembourg and Norway. Cheese is thought to be the cause of the disease – and the ECDC said a number of control measures were now in place to stop the outbreak. However, it warned that new infections were possible.

Yersinia bacteria are contracted by eating or drinking contaminated food, including undercooked meat, unpasteurized dairy products, or contaminated water. The bacteria can also spread through person-to-person or direct contact with infected animals.

Officials said the victims were of all ages, with the youngest being 3 and the oldest 85. The largest number of infected was in France’s Provence-Alpes-Côted’ Azur region, with 57 cases, but cases have been reported in all regions of mainland France.

The study found that people who were infected were mostly eating raw goat’s milk cheese, a specialty from southeastern France. Belgium, Luxembourg and Norway each reported one case. It said: “Given the distribution of the affected products in several EU/EEA countries, the risk of acquiring yersinosis is high among consumers who purchased the affected products or were exposed in other settings before the control measures were implemented.”

It said that the reported cases “may represent a small proportion of all cases”. The ECDC said it was monitoring the event through its epidemic intelligence activities. Acute Yersiniosis manifests as diarrhea, abdominal pain, nausea, vomiting and fever.

Symptoms usually appear 4-7 days after exposure to the bacteria, which can be found in contaminated food, water or milk, or through contact with animals or people. The contagious period is usually 2-3 weeks, but people can remain contagious for up to three months after the diarrhea stops. Anyone who is infected is told to wash their hands regularly to avoid infecting others.

Wash your hands with warm water and soap for 20 seconds

• After using the toilet
• After changing diapers
• After touching animals
• For eating or preparing food

Bloody diarrhea is more common in children than in adults. Sepsis has been described in infants and patients who are immunocompromised or in an iron overload state with an overall mortality rate of 50 percent.