Superbug's new strain thrives outside hospitals

Superbug's new strain thrives outside hospitals
By Mark Henderson, Science Correspondent

www.timesonline.co.uk...


A NEW strain of the drug- resistant superbug MRSA has escaped from hospitals to infect thousands of healthy adults across the United States, hitting hardest among homosexual men.
The bacterium, which normally affects only sick and elderly hospital in-patients, is striking fit Americans with no links to the hospitals in which it thrives, raising fears of an epidemic that could spread to Britain. The germs, which can withstand many common antibiotics, are transmitted by skin contact, with no need for an open wound.

Outbreaks have been reported in Los Angeles, San Francisco, New York, Boston and Miami. Most of those affected are homosexual men and prison inmates, but athletes and schoolchildren involved in contact sports have also fallen ill. Precise figures for the number of infections are not available, because MRSA is not a notifiable disease in the United States, but public health officials believe cases already run into the thousands, with several deaths.

The disease normally manifests itself as a skin condition, beginning with sores that resemble insect bites, and progressing to cause painful abscesses and boils. In rarer cases, when it reaches the lungs or the bloodstream, it can cause life-threatening pneumonia or septicaemia.

MRSA, which stands for methicillin-resistant Staphylococcus aureus, has for years been a problem in hospitals, where it infects open wounds and bedsores, taking advantage of the weakened immune systems of seriously ill or elderly patients.It is named as a contributory cause of death in 20 per cent of death certificates issued in British hospitals where staphylococcal infection was a factor.

The bacteria, however, have never been considered dangerous beyond the wards. The emergence of a strain that is spreading through the wider community, details of which are reported today in New Scientist magazine, has alarmed public health officials on both sides of the Atlantic. Scott Fridkin, a medical epidemiologist at the US Centres for Disease Control and Prevention (CDC) in Atlanta, said: �We are greatly concerned that MRSA has emerged in the community in people with no ties to healthcare.�

Tyrone Pitt, deputy director of the Laboratory of Healthcare Associated Infections, said that while there was no evidence that the strain had arrived in Britain, it was a genuine threat. �It is very difficult to predict its impact. If it manifests itself just as a skin infection, that is not that threatening. If the result is pneumonia in relatively healthy people, that�s a completely different scenario,� he said.

The Atlanta centre has yet to complete testing to confirm the strain that is spreading in the community, but health officials in Los Angeles said all the outbreaks there appeared to have been caused by a strain first isolated in New York in 1997. Most of the US cases so far have occurred in San Francisco and Los Angeles, among homosexual men who have had multiple sexual partners. The disease is not thought to be sexually transmitted, but as it is contagious through skin contact, sexual promiscuity has an indirect effect on risk. Its effects are not confined to HIV-positive men.

Several prisons in California have reported MRSA outbreaks among inmates, and there have also been outbreaks in schools, particularly among athletes involved in contact sports. In Pasadena 50 pupils at one school were diagnosed with the condition, mostly members of the school�s football team.