U.S. warns of W. Nile infections from blood

Transfusions can transmit disease

CDC confirms as cause in six cases

October 29, 2002|By Robyn Suriano | Robyn Suriano,SPECIAL TO THE SUN

Federal officials confirmed yesterday for the first time that West Nile can be transmitted through blood transfusions, underscoring the need for a test to screen donated blood for the potentially deadly virus.

Experimental tests may be ready as early as next summer, but in the meantime, the Food and Drug Administration is urging blood banks to question donors more thoroughly and quickly remove suspected blood from their shelves.

The topic of West Nile drew a large crowd yesterday at the annual meeting of the American Association of Blood Banks, being held this week in Orlando.

"We are operating at a high level of alert and concern in an evolving situation," said Dr. Jay Epstein, of the FDA's office of blood research and review.

To date, the Centers for Disease Control and Prevention has nailed down blood transfusions as the cause of six cases of West Nile encephalitis. Another 27 potential cases remain under investigation. West Nile is a mosquito-borne disease that usually is passed to humans through bites from infected insects. The United States is in the worst outbreak of the disease since it first appeared here in 1999.

More than 3,300 human infections have been documented and 188 people have died from West Nile this year.

But officials said it's likely as many as 300,000 people have contracted the virus across the country. Because most don't show any symptoms, health officials only become aware of cases that lead to severe problems such as encephalitis, a sometimes-fatal brain infection.

Even so, officials say the 4.5 million Americans who get blood transfusions every year should not be overly concerned. They think the risk of getting West Nile through tainted blood remains low.

"Obviously people who need a blood transfusion have other things to be worried about," said Dr. Lyle Petersen, a West Nile expert with the CDC in Fort Collins, Colo. "The benefits of getting a blood transfusion outweigh the risks."

Compared with other viruses, West Nile exists at very low levels in the blood, Epstein said. Any test to screen for the virus would have to be highly sensitive to pick up the virus.

The FDA is inviting the scientific community to a meeting early next month to discuss the challenges and possibilities for developing such a test.

Existing tests are not applicable to everyday screening in blood banks, officials said, because they are too time-consuming and costly.

"We're talking about being able to test thousands of specimens on any given day quickly and accurately," said Dr. Mary Chamberland, assistant director for blood safety at the CDC.

When health officials found that HIV, the virus that causes AIDS, could be transmitted through blood transfusions in the early 1980s, it took time to get a test ready for widespread use. All donated blood has been screened for HIV since 1985.

Despite the difficulties, blood bank officials are confident a test can be developed.

"There's a lot of midnight oil being burned in labs across the country already working on this problem," said Mike Pratt, executive vice president of technical services at Central Florida Blood Bank, which provides blood to area hospitals and health care facilities.

To deal with the problems now, the FDA has released new recommendations to blood banks that emphasize the need to question donors about recent symptoms that could indicate exposure to West Nile. These include fever, chills, headache or rashes.

Blood banks also are urging donors to contact them if any of these symptoms develop after they give blood, because people may have the virus up to two weeks before showing any signs of it.

Robyn Suriano writes for the Orlando Sentinel, a Tribune Publishing newspaper.

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