At least 2,000 schoolchildren have been struck down by a flu-like virus that has spread around Sussex.

Classrooms in many schools in the county are half empty as students stay at home to recover.

Health experts believe the outbreak has reached its peak.

It is thought that cases will peter out next week during the half-term holiday.

A spokeswoman for the Health Protection Advisory Service in Sussex said its team estimated about 2,000 schoolchildren were affected.

She said that the majority, about 90 per cent, were infected by the flu virus.

A further ten per cent were suffering from sickness and diarrhoea caused by the norovirus or winter vomiting bug.

She said: "This is quite a large amount but something like this can be difficult to contain because so many children are sitting, playing and studying close together in the school environment so the chances of the infection passing between them is so much higher.

"Now that the half-term holiday is here, it should ease things a great deal and we are hopeful that by the time term starts again in a week, things should be much better.

"It is a well-known winter strain of flu which usually appears in some form each year.

"If anyone had the vaccination last year as part of the Government's annual campaign then they should be protected.

"However, it is mainly offered to elderly people and those with chronic illnesses.

"Almost all of the children will not have had that vaccination."

The worst schools affected are in East Sussex although there have been reports of smaller outbreaks at schools in Brighton and Hove and West Sussex.

Schools experiencing problems include Manor Primary, Uckfield; Claverham Community College, Battle; King Offa Primary, Bexhill; Heathfield Community College; Broad Oak Primary, Heathfield; Hellingly Primary; St Leonard's Primary; White House Primary, Hailsham; and Hazel Court School, Eastbourne.

Staff at Davison High School in Worthing said it had not experienced any problems.

Hazelwick School in Crawley had several absences because of flu a week or so ago but things were back to normal.

Flu symptoms can be debilitating but people usually recover within a week to ten days.

The general advice is to stay at home, keep warm and drink plenty of fluids.

Uckfield Community College, which has 1,650 pupils, has around 350 off sick this week, Deputy head Geoff Evans said: "It has peaked here at the moment. Only a couple of days ago, the school nurse sent home 47 students.

"Staff seemed to have escaped the illness and lessons are continuing but in most sessions there are six, seven or eight pupils missing.

"We have managed to get through it but we are relieved that it is half-term as that should sort things out."

About 250 students were off sick at Varndean School in Brighton in the last week.

Brenda Muzio of student services said: "We have about 1,250 pupils so that is quite a large number.

"Some students were sent home when they came in because they were suffering symptoms and some of our classes have been halved, although lessons have gone on as normal.

"But half-term next week should help matters a lot though."