At least 66 schools in England have suffered swine flu outbreaks since the start of the school term, figures showed today.
New data from the British government also showed the number of swine flu cases across the country has almost doubled in a week, from an estimated 5,000 to 9,000.
Chief Medical Officer Liam Donaldson said the number of cases was still relatively low, but there were signs a second wave of swine flu could be on its way.
He said the data on schools was not being systematically collected and he expected the number affected to be higher.
Asked if the figure of 66 was on the low side, he said: “I think there will be more than that.”
He said the outbreak correlated with rises in the number of cases seen in young people.
Measures that would make a big difference in schools included regularly washing hands with soap and water, throwing tissues away and covering the mouth and nose when coughing and sneezing.
“Research across a lot of children’s diseases does show that that cuts the rate,” he said.
“Parents of children with underlying illnesses should consult their doctor (if they have flu) and children with flu-like symptoms and whose condition deteriorates should consult their doctor because that might be an indication that they have serious complications of flu or have another serious illness of childhood.”