Thousands of letters are going out to the parents of schoolchildren across Shropshire as health chiefs concede defeat in the battle to contain swine flu, it was revealed today.

The move came as it emerged the virus had claimed its fourth UK victim with a death being confirmed in London of a 19-year-old man who was also suffering serious underlying health problems.

Shropshire Council warns in letters to parents that growing numbers of pupils are reporting sick after going down with flu-like symptoms but urges parents to remain calm.

The authority is, however, calling on them to keep their children off school if they or a member of the family develop symptoms such as a cough, sore throat, runny nose, joint and limb pains or headaches.

The letters have been sent to schools right across the Shropshire Council area for them to distribute.

Parents are being told in the letters that schools are monitoring rates of absenteeism and looking out for symptoms of swine flu among both staff and pupils.

The council also says it is working closely with local health organisations after the Government revealed the virus was now on the loose nationwide and the number of new cases could soon reach 100,000 a day.

Shropshire Council spokesman Simon Alton said: “The national line is that there will no longer be confirmed or suspected cases announced because a running total will no longer be kept.

“As a result, letters have been sent home to parents of all pupils at schools in Shrop- shire informing them of the national situation and advising them about the health precautions to take. We are now in the treatment phase of the illness, as opposed to the containment phase.”

A Telford & Wrekin Council spokesman today confir-med it had written to its schools to update them on the swine flu situation and would be writing to parents.

Meanwhile, the Mary Webb Sports Centre in Pontesbury, Shrewsbury, reopen- ed today after being shut on Tuesday for a “deep clean” after a male member of staff contracted the virus.

The Government’s Chief Medical Officer Sir Liam Don- aldson today warned against panic-buying “counterfeit” anti-swine flu drugs online.

By Simon Hardy