By Nick Triggle
Health reporter, BBC News
Reports of swine flu parties have been received by doctors
Throwing "swine flu parties" in an attempt to get immunity against the virus while it is a fairly mild form is not a good idea, doctors say.
Reports have emerged of people intentionally mixing with friends who have flu.
Their reasoning is that it is best to be infected before the winter when the virus could become more deadly.
But public health expert Dr Richard Jarvis said such behaviour could undermine the fight against swine flu.
He also stressed while it was a mild flu, people would still be putting their health and the health of their children at risk.
Dr Jarvis, chairman of the British Medical Association's public health committee, has been working for the Health Protection Agency in the north west to help test, diagnose and treat people who have got swine flu.
He said: "I have heard of reports of people throwing swine flu parties.
"I don't think it is a good idea. I would not want it myself.
"It is quite a mild virus, but people still get ill and there is a risk of mortality."
Health service pressure
Dr Jarvis, who was speaking in his BMA capacity at the union's conference in Liverpool, admitted getting the virus now was likely to give people immunity even if it mutated slightly to become more virulent.
But he added that if people actively sought to get flu, health services may not be able to act in the same way as they are doing now.
The approach to date - although it is changing in the areas such as Birmingham and London which have the largest outbreaks - has been based on containment.
This has involved close monitoring of flu patients and giving their close contacts drugs to try to prevent the virus developing.
Dr Jarvis said: "If we get to the point where containment is not possible we will not be able to monitor cases as closely or get anti-virals out as quickly. Will we consider it a mild virus then?
"The response so far has been superb. We have contained better than we expected and that has given us time. We are getting closer to a vaccine and we want that to continue.
"Going out to try to get the virus will just aid its spread."
Dr Jarvis also warned that public health doctors like himself were risking burnout because of the long hours they were putting in on the front-line of the fight against flu.
"Tired doctors make poor decisions and chronically tired doctors become prone to a variety of health problems."
Dr Vivienne Nathanson, the BMA's head of science and ethics, praised the approach of the UK public since the first outbreak.
"People have not panicked. They have handled it sensibly by following the official advice."
But as the cases mount, Dr Nathanson said she was concerned about suggestions some business are buying in stocks of anti-viral drugs to treat their staff.
As well as having limited effectiveness, Dr Nathanson said businesses needed to be wary of buying fake medicines.
And she added: "There is also the issue of resistance. If we overuse them and use them inappropriately we are more likely to get resistance.
"The best advice is good hand hygiene. Use tissues when you sneeze, bin them and wash your hands."
Sir Liam Donaldson, the chief medical officer for England, said: "It is seriously flawed thinking to allow the virus to spread unabated through 'swine flu parties'.
"We don't yet know enough about the risk profile of the virus, and whilst it has generally been mild in the UK, in some parts of the world young previously healthy adults have died."