Swine flu has affected a number of schools in Lancashire but parents are advised to send their children in as normal.
Health protection chiefs have revealed they have been inundated with calls from concerned parents seeking advice about whether to send their child to school if there have been cases of swine flu.
Experts say schools are being advised to stay open as closing them will not curtail the spread of swine flu.
Swine flu has moved from a containment stage to a treatment stage and GPs are now responsible for diagnosing people with swine flu if they feel they show the symptoms.
Before, anyone suspected as having swine flu was swabbed and tested before being diagnosed and treated for the illness.
But now, everyone showing flu-like symptoms is being treated as if it is swine flu.
This, together with the increasing spread of the disease, has led to greater numbers of people being diagnosed with swine flu.
One of the Preston schools hit by cases of swine flu is St Augustine's Catholic Primary School, on St Austin's Place, Avenham, Preston.
Deputy head John Entwistle told the Lancashire Evening Post that letters had gone out to parents telling them what to do if they suspect their child has swine flu and giving them hygiene advice to prevent swine flu.
He said: "We have had a few parents talking to us about their concerns, but there is no mass panic about this and parents seem happy with the way the school is dealing with the issue.
"The school is open as normal and we are following the guidance set down by the Health Protection Agency and the Local Education Authority."
Health chiefs advise that any person diagnosed with swine flu should stay off school or work until they are completely recovered and for a minimum of seven days, but for other members of the family who have no symptoms to go to school or work as normal.
Dr John Astbury, consultant in communicable diseases at the Cumbria and Lancashire Health Protection Agency, said: "We have been snowed under with calls from parents.
"Our advice is for schools to stay open. There is no point closing them as it will not affect the spread of swine flu."