Cause of rising US infections unclear, experts say

ATLANTA, May 12 (Reuters) The cause of increasing rare but deadly bacterial infections, including a handful of cases in women who have taken the controversial RU-486 abortion pill, is still unclear and needs further study, US health experts said.

Two sometimes fatal bugs -- Clostridium sordellii and Clostridium difficile -- are a particular worry as antibiotic resistance grows and infections occur in people usually not at risk, doctors and researchers said, yesterday.

While infections have been reported in drug users, surgical patients and accident victims, including men, cases in women who took RU-486 drew the most scrutiny at the Centers for Disease Control and Prevention's Atlanta headquarters.

Officials from the CDC, Food and Drug Administration and National Institutes of Health sought input from outside experts on what research and tracking systems are needed.

Paul Seligman, FDA associate director for safety policy, said it was not clear what is causing the spike.

''What we do know is that in this country we are seeing the simultaneous emergence of two virulent, often fatal illnesses affecting otherwise healthy people,'' he said.

More than 200,000 Clostridium difficile cases occur each year in the United States, experts said. The diarrhea-causing disease is usually manageable but has recently become more difficult to treat.

Clostridium sordellii is far more rare and previously was not known to be toxic. ''Over the past few years the picture has changed,'' Seligman told the panelists.

Drawing the most scrutiny were cases involving RU-486.

The drug, made by Danco Laboratories LLC, is taken with another called misoprostol early in pregnancy to trigger an abortion. It is not related to emergency contraception.

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