There has been a big increase in cases of a potentially serious stomach bug among children in recent weeks, the Health Protection Surveillance Centre (HPSC) has warned.

Cryptosporidiosis is a type of gastroenteritis that affects humans and animals. It is caused by a microscopic parasite called Cryptosporidium. When an animal or person is infected, the Cryptosporidium bug lives in the bowels and passes out of the body via the faeces. People can develop the illness when they come into contact with this contaminated faeces.

"Cryptosporidiosis is spread when the bug passes from the person or animal in the stools or manure, and anything contaminated by the stools or manure (hands, touch surfaces, handles, food, water and outdoor surfaces) can lead to a person becoming infected," explained HPSC specialist in public health medicine, Dr Paul McKeown.

The most common symptom of the illness is watery diarrhoea. Other symptoms can include stomach cramps, nausea, vomiting and a temperature. People with weak immune systems can suffer severe symptoms if infected.

"Since the beginning of March, the number of cases of cryptosporidiosis has more than doubled in comparison to the average rates, especially in small children aged one to four years of age.

"When children spend time outdoors and in particular on farms, they are more likely to pick up this bug, and it is important they wash their hands regularly with soap under warm running water," Dr McKeown said.

The best way to prevent this illness is to regularly wash hands with soap and warm running water. Alcohol hand gel will not kill the Cryptosporidum bug.

Hands should always be washed:
-After using the toilet
-Before eating
-Before preparing food
-After playing or being outside (especially on a farm)
-After touching dirty outdoor clothes or boots
-After touching your pets.

The HPSC also advises that children do not eat food outdoors, especially on farms or in the open countryside, unless their hands have been cleaned.

Symptoms usually begin around a week after swallowing the bug, and they last around one week, although they can last longer. For more information on the illness, click here.