NHS organisations in England are playing down the extent of the current outbreak of norovirus infection.
The highly contagious infection, which causes acute vomiting and diarrhoea, has resulted in the closure of some hospital wards across the country, and the number of laboratory confirmed infections is at its highest since 2002.
But a spokeswoman for the Health Protection Agency said that this rise was partly due to the introduction of a more sensitive test for norovirus, which had been rolled out across all testing sites last year.
“The season did start uncharacteristically early this year, with a rise in reported cases starting in the week of 17 to 24 September,” she admitted. “Normally, the season runs from October or November.”
“But this also happened last year, and then the season also stopped uncharacteristically early,” she added.
In 1986 there were 319 laboratory reported cases, but by 2006 the number had risen to 4446, figures from the Health Protection Agency show. The number rose in 2002 but then almost halved in 2003, before rising again.
Peaks and troughs were part of the normal pattern of infection, said the agency spokeswoman.
“In 2002 a new strain emerged, and in 2006 influenza virus B was also circulating, which caused similar symptoms,” prompting patients to see their GP and be tested, she said.
Infected patients often just stay at home, and acute care trusts are not obliged to monitor or report cases to strategic health authorities, so accurate figures are hard to come by. The latest incidence figures were due to be published shortly after the BMJ went to press.
Nevertheless, the spokeswoman said that reports of as many as two million people currently infected had perhaps been exaggerated.
“We don’t know where that figure has come from. We estimate it is more likely to be between 600 000 and one million,” she said.
The picture on the ground seems to be mixed. No ward closures have been reported in the NHS North East region, but nine wards were closed in the South West last week, most of them in Bath, and primary care staff had been drafted in to help out in emergency care.
A spokeswoman for the South West Strategic Health Authority said that one ward had since reopened over the weekend. “The picture is better than it was last week,” she said. “This is not unexpected, and it’s not worse than in other years.”
In Yorkshire and Humber 11 wards were closed last week, rising to 18 by Monday, five of them in Sheffield.
In the East of England two of the 18 NHS trusts reported closures, and four wards at Bedford Hospital NHS Trust were closed to new admissions.
In the West Midlands one trust had cancelled routine elective surgery until 19 January, while two others had closed seven wards, said a spokesperson. “But we would expect two to reopen within the next 48 hours.”