The number of swine flu cases has jumped by nearly 50 per cent in a week, figures released yesterday indicate.

Data from a sample of GPs’ surgeries, seen by The Times, shows that up to 40,000 people complained to their doctor last week of “flu-like illness” in England and Wales, with a huge rise in the number of young children being affected.

The report shows that the highest rates of reported illness are in children aged five to 14, with 160 of every 100,000 in this age group reporting symptoms, followed by 114 per 100,000 of the 0 to four-year-olds.

Overall, the rate of people complaining of symptoms increased to 73.4 cases for every 100,000 people in the week to Sunday, compared to 50.3 cases per 100,000 the week before.

This is a rise of 46 per cent and is equivalent to about 39,150 people across the country reporting symptoms compared to about 27,000 people who did so the previous week.

The figures, from the Royal College of GPs (RCGP), are based on a sample of 84 doctors’ surgeries across the country. Although they do not provide a total of confirmed cases of the H1N1 virus they are used by the Government as an official measure of how the outbreak is spreading.

The figures show the current outbreak is already worse than the seasonal flu experienced over Christmas and the New Year which was the worst for eight years. The winter flu outbreak hit a peak of 69 cases per 100,000 people across England and Wales. Doctors would normally expect to see fewer than 30 cases per 100,000 during the summer.

The Health Protection Agency said last week that the number of people who actually are infected with the virus could be as low as 28 per cent of those reporting symptoms, or about 11,000 of those contacting their GP last week. Nearly 200,000 concerned people have also contacted NHS Direct about flu symptoms since April.

London is still the area worst affected by the current outbreak although the number of people reporting symptoms last week dropped to around 140 per 100,000 population — but cases in all other areas of the country are rising.

By region, reports of illness in central parts of the country more than doubled from 43 to 94 cases per 100,000 in a week.

In the South, the average rate of cases was 75 per 100,000 people last week, but the rate in the North also rose sharply from 6.6 to 37.2 in the same period.

Between 5,000 and 7,000 deaths are attributed to flu in a typical winter, although the number can rise to more than 10,000 in bad years. Typically, the elderly will make up the vast majority of these fatal cases.

But experts are concerned that the H1N1 swine flu strain is mainly affecting younger people. There have so far been 17 swine flu-related deaths in the UK, including a child of six, but ages and details of underlying health conditions are not known for all the victims.

According to figures released last week, of the 335 people being treated in hospital for a swine flu infection about one in three (107) were aged 15 or younger.

An update on the number of people being treated in hospital with flu and further detail on laboratory-confirmed cases is expected today.

Professor Steve Field, chairman of the RCGP, said that the NHS was well-prepared for a worst-case scenario.

“There are robust plans in place in all hospitals to manage any increase in the number of patients with influenza and an increase in patients who have respiratory illnesses, such as pneumonia, bronchitis or asthma,” he said.

“As the numbers increase, a proportion of those will inevitably need intensive care, as some swine flu patients are already getting. These plans will include the use of hospital beds, the postponement of elective surgery, the use of surgical beds and the sharing of patients between hospitals which, if it got very severe, could see some patients moved out of their locality.”

Explore Health

• Expert Advice

• Health Features

• Mental Health

• Alternative Medicine

• Child Health

• Health Club