Four other workers at the same hospital also contracted Panton-Valentine Leukocidin-positive (PVL) MRSA, with two of their friends, said the Health Protection Agency. An investigation subsequently found that the strain had killed a patient at the hospital earlier this year.

The strain, which is particularly virulent, attacks healthy young people and can cause symptoms ranging from minor infections in the skin and soft tissue to a form of pneumonia that can kill in 24 hours.

The outbreak, which has only just been reported, was identified when a previously healthy female healthcare worker, named only as “Case One”, developed a severe MRSA infection and pneumonia and died after emergency surgery in September, the agency said.

The bacterium that she had contracted, PVL-positive MRSA, had never been found to cause a death inside a hospital. It was contracted by at least three other workers in two wards in a West Midlands hospital, and two of their friends.

It was also found to have caused the death of a patient at the hospital in March.

A statement from the agency said: “Eight cases of PVL- positive community-associated MRSA have been identified among individuals in a hospital and their close household contacts in the West Midlands. Four of these individuals developed an infection, two of whom subsequently died.”

The agency declined to give further details but said that extensive contact tracing had not identified more cases at the hospital.

However, the strain has been found in other hospitals, including the University Hospital of North Staffordshire, which is understood to have identified two non-fatal cases of the bug.

The discovery is significant as hospital-acquired MRSA has tended to affect elderly and infirm patients rather than younger people.

PVL is a toxin that destroys white blood cells, which are the key to fighting infectious diseases. It occurs in about 2 per cent of strains of the common bacterium known as staphylococcus aureus, which is termed MRSA when it is resistant to the antibiotic methicillin.

Although it is rare, a small number of cases of PVL- positive MRSA have been reported across England and Wales — however, these have usually been in the community rather than a hospital.

The strain is thought to have caused the death of a Royal Marine recruit, Richard Campbell-Smith, 18, in 2004. Forty-eight hours before the young recruit died, he scratched himself on a gorse bush during a training exercise and contracted an MRSA-related infection.

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