“Therefore extensive use of prophylaxis is no longer appropriate, as people are likely to be repeatedly exposed to the disease.”

She added: “In view of the developing situation, there will be a move from the laboratory confirmation of all cases to clinical diagnosis of some cases.

“This means that people who have been in close contact with a confirmed case and who have flu-like symptoms may be clinically diagnosed as having swine flu without the need necessarily for a swab test.”

Dr Sue Ibbotson, West Midlands regional director for the Health Protection Agency, said: “We have always said that this virus would spread but that we would monitor this situation and adjust our approach as necessary.

“The approach we have taken up to now has been vital in slowing the spread of swine flu, which has not only limited the impact of the disease but has also given us time to learn more about the virus.

“As we now have significant levels of transmission of swine flu within certain parts of Birmingham, it is appropriate to make adjustments to accommodate the specific local circumstances.”

She added: “We know that in the majority of swine flu patients so far the disease is generally mild, but it is proving severe in a small minority of cases.

“We will continue to look at each school on a case-by-case basis and perform risk assessments at each school, taking into account their individual situation.

“We will not automatically be recommending closure unless there are special circumstances.”

In total, 34 schools are currently thought to be closed in the West Midlands because of the disease.

Shireland Collegiate Academy yesterday became the first Black Country school to shut its doors due to the disease, with pupils sent home with letters informing parents that it would be closed for a week.

Park View Business and Enterprise School in Alum Rock, Wattville Primary in Handsworth, Lordswood Boys’ School in Harborne and Wilkes Green Infants’ School in Handsworth have also been closed for a week.

At St Benedict’s Infant School in Small Heath, about 30 children have been sent home feeling unwell, but the school has not yet been closed.