The condition is caused by a strain of bacteria, known as methicillin-sensitive Staphylococcus aureus, that produces a toxin called Panton-Valentine leukocidin.

Public Health England investigators examined a cluster of suspected infections at the same rugby team between August 2013 and February 2014.

They found four cases of the infection, having screened about 60 members.

And their tests revealed an identical strain of bacteria was responsible for all four infections, suggesting the bug was being transmitted between people.
Cellulits of leg The bacteria-toxin combination can cause skin infections that can spread to deeper tissues

Players were then asked to complete questionnaires to help doctors identify which activities were putting them at risk.

Some 20% said they shared towels regularly, 10% admitted to sharing razors and 5% shared clothing despite almost a third saying they had suffered skin conditions in the last year.

Experts also noted that some players shared cold baths after games.

'High-risk behaviour'

Dr Deepti Kumar, at Public Health England, said: "The investigation identified a number of high-risk practices among the players which increase their chances of getting an infection, such as sharing towels and razors, and sharing ice baths with their fellow team members.

"We would urge any sportsperson who plays a sport where cuts and grazes are commonplace to practise good hygiene and not share any item with fellow team members to reduce their risk of developing an infection."

The medical team said there were likely to be more cases that hadn't been identified as infections can spread to other teams during games.

And they warned that as the bug can spread easily, family members and close contacts of those infected could need medical attention too.

Data from Public Health England shows there are between 1,200 and 1,500 cases of PVL-MSSA nationally each year.

And according to the British Association of Dermatology, wrestlers and people involved in other close-contact sports are also at risk.

Treatment involves antibiotics, surgical drainage of any abscesses and more extensive hospital care for serious cases.