Doctors Say They’ve Found Cause of Toxic Shock

Doctors said Wednesday that they have solved the mystery of how some kinds of highly absorbent tampons contribute to toxic shock syndrome and that their discovery should allow the production of safe tampons.

Researchers at Harvard Medical School said two kinds of fiber used in tampons foster the production of a bacterial poison that causes the rare but dangerous disorder.

The fibers do this by removing magnesium from the vagina, creating an ideal environment for bacteria to make the dangerous toxin. If magnesium is added to tampons made from this material, they appear to be safe, the researchers said.

“We hope we have found a means for making tampon fibers such that they will not stimulate maximum toxic production,” Dr. Edward H. Kass said. “We hope what will come out is a safer product with maximum absorbency.”

Absorbent Materials

The two materials that absorb magnesium are polyester foam and polyacrylate rayon. Neither is now being sold. Polyester foam has not been used since Rely tampons were taken off the market in 1980. Tampons with polyacrylate rayon were recalled in March after the Harvard researchers told manufacturers of their findings.

Tampons now being sold are made from cotton, viscose rayon and carboxymethylcellulose, materials that doctors said are safe.

The study, financed by Tambrands, which makes the Tampax brand of tampons, is being published in the June issue of the Journal of Infectious Diseases.

The national Centers for Disease Control said that, between 1980 and 1984, 2,683 persons suffered toxic shock, and 114 of them died.

Until now, researchers had speculated that the tampons’ high absorbency was somehow linked to toxic shock. Experts recommended that women change tampons every few hours. But the Harvard team said there is no evidence that that helps prevent the syndrome.