The chances of being infected with the deadly AIDS virus from a blood transfusion is apparently lower than previously estimated and seems to be continuing to decrease, researchers say.
In a report published in The New England Journal of Medicine, the American Red Cross estimated that in 1987 the odds of the average blood transfusion recipient being infected with the AIDS virus was about one in 28,000.Since the risk was decreasing by about 30 percent each year, the danger is probably down to about one in 35,000 by now, Roger Dodd of the Red Cross said in an interview.
"The major finding is that the risk on a nationwide basis is probably lower than that cited on the basis of other studies," Dodd said.
Previous estimates were probably higher because they were based on smaller numbers of blood donors in areas where AIDS is more common, Dodd said. The new study is based on more than 17 million blood donations nationwide between 1985 and 1987.
"This tells us our efforts to reduce transmission-associated AIDS have been fruitful and the the actual risk has been reduced quite significantly," Dodd said.
He added, however, that the blood supply could be made even safer by detering more people at high risk for AIDS from donating blood and encouraging more donations from those at low risk, such as women and those who donated previously.
Dr. John Ward of the Centers for Disease Control in Atlanta, who previously estimated the AIDS risk from donated blood was higher, said even if the risk is low more needs to be done to reduce it further.
"All these risks show that the risk is low but that a risk still remains. No matter how low it is, that means we have to constantly evaluate how we are safe-guarding the blood supply," Ward said.
An accompanying study by the National Institutes of Health found a fivefold decrease in the number of blood donors testing positively for AIDS at an American Red Cross blood center in Washington from 1985 through 1988.