UV Method May Cleanse Blood of Microbes

Ultraviolet light might someday help remove viruses and bacteria from donated blood, scientists say.

A method being tested zaps viruses, such as HIV and hepatitis, and bacteria, such as the microbe that causes syphilis.

Typically, blood bank workers perform separate tests on donated blood to make sure it is not contaminated with various microbes. The new UV technology could, instead, destroy all the microbes at once.

The method is analogous to pasteurizing milk, says Dr. Gerald Sandler director of the blood bank and donor service of Georgetown University Hospital in Washington.

Works by Inactivating Genetic Material

Called "pathogen inactivation," the method involves adding a solution to the blood and then shining UV light onto it. The chemicals in the liquid bind to the DNA and RNA inside the microbes and prevent them from reproducing.

The process, being developed by Cerus of Concord, Calif., could theoretically kill not only known viruses but also brand-new ones that have not been identified.

When the virus that caused AIDS first emerged in 1981, it entered the blood supply, unknown to physicians. This method, which is undergoing clinical trials, could prevent that from happening again.

Prions Still Could Get Through

But there are limitations. The process would not catch diseases with a protein basis, such as the prion, believed to be responsible for the human version of mad cow disease.

Dr. Bernadine Healy, CEO and president of the American Red Cross, says the research is promising but that her group will continue to do standard screening.

"It is important to know there's not one magic bullet to make the blood supply safe," Healy said.