MORE than 100 children have been off sick after an outbreak of an infectious virus at St Joseph's High School in Horwich.

Pupils were sent home after viral gastroenteritis spread through the school.

The infection is thought to have spread quickly because many of the children were working closely together on the school production of A Midsummer Night's Dream.

Bolton Primary Care Trust sent letters and a leaflet explaining the symptoms of gastroenteritis and how to treat it to all parents who have children at the school.

Headteacher Lee Conley said: "We had 165 children in the school production and many started going down sick. Six went down sick at first.

"We thought they had all eaten burgers from the same place and that they had food poisoning. The next day, there were 23 children and some of those had not eaten burgers.

"I spoke to several doctors and later found out it was the winter sickness virus.

"Since then, we sent 40 children home last Monday with the virus and we had about 60 phone calls from parents saying their children were ill. The school nurse was very busy.

"The situation is now under control and those children are now back in school.

"The pupils on the school production were brilliant. It was a real team effort to keep the show going."

The virus started to spread through the school two weeks ago and most pupils are returning to school this week.

Viral gastroenteritis causes vomiting, diarrhoea, stomach pains and fever-like symptoms which usually last 24 to 48 hours. Children should not return to school until they have been free from all symptoms for 48 hours.

The bug is passed on from person to person or through food contaminated by a sufferer. Young people are particularly vulnerable.

To prevent it from spreading, people should always wash their hands properly after going to the toilet, after contact with pets, after changing a baby's nappy, and before preparing and serving food and before eating.

A Bolton PCT spokesman said: "It is a common virus at this time of year in schools and nurseries and it spreads quickly.

"Every school and nursery are issued with an infection control manual, which they can consult for symptoms and the PCT is always on hand for advice."