Transplant Worries Allayed

The biggest study yet on the safety of transplanting body parts from pigs into humans proved reassuring: None of the 160 patients studied caught a worrisome pig virus.

The study in today's edition of the journal Science could spur more experiments using animals as potential organ donors.

But scientists stressed that this highly experimental field called "xenotransplantation"--transplanting organs or cells from one species to another--still requires caution because the new study doesn't prove it's safe.

Doctors hope xenotransplantation will one day save thousands of lives by easing a worldwide shortage of donated organs. But some scientists fear it also could cause new epidemics.

Concern was heightened when researchers recently discovered that the genes of all pigs--the species most likely to be used in attempted xenotransplants--harbor a previously unknown virus that test-tube experiments showed could infect human cells.

The virus didn't harm the pigs, but nobody knew if it would hurt humans.

So scientists at the British biotechnology company Imutran Ltd. tracked down 160 patients from eight countries who were experimentally treated with living pig tissue, such as pancreatic cell transplants for diabetes.

Using the most rigorous viral testing available--and backed with confirmatory testing by the U.S. government--Imutran scientists found no evidence that these patients were infected with the pig virus.

Still, scientists stress that all xenotransplantation experiments--like those currently implanting pig cells into Parkinson's disease patients' brains--must be closely monitored.

Drug-Resistant Germ's Toll

Four children have died, two of them this year, from a common staph infection that is growing increasingly resistant to the antibiotics used to treat it, federal health experts said yesterday.

The Centers for Disease Control and Prevention (CDC) said the deaths among children ranging in age from 12 months to 13 years demonstrate that drug-resistant strains of staphylococcus bacteria are spreading from hospitals into communities.

The deaths, which occurred in previously healthy children in Minnesota and North Dakota beginning in August 1997, were caused by methicillin-resistant strains of staphylococcus aureus, the leading cause of hospital-related infections, researchers said.

Staph has been successfully treated with penicillin since 1947, but strains began showing resistance in the 1950s. Methicillin was developed in the 1960s, and the first reported cases of methicillin-resistant staph occurred in the United States in 1968.

CDC researchers confirmed a case in Japan in 1997 in which the bacteria successfully defended themselves against vancomycin, an antibiotic considered to be the last line of defense against staph infection.

Excessive and inappropriate use of antibiotics is a major cause of antibiotic resistance.