Usually the area will need to be surgically opened and all debris and infected material removed.

Like squeezing infected material out of a cut.

They occur when an infection causes pus and infected material to collect in the skin.

This can push the infected material into the deeper tissues.

"There may have been a problem - before 1989, when it was possible some infected material may have gotten onto the market."

Transmission due to medical procedures, such as injection or transplantation of infected material.

The main form of spreading of P. fragariae is through infected material.

"You have to keep digging deeper and deeper to get out all the infected material," he said.

Unfortunately, primitive methods, which used a live virus from infected material, could result in the patient getting a full-blown case of the disease.

Because the 10 British cases affected people younger than 42 years, many people are concerned about the possible dangers of feeding infected material to children.