HIV scares up risk debate
By WES ALLISON, Times Staff Writer
There are lots of things to fear. Cancer and heart disease, terrorism and plane crashes, death on the highway and sharks in the surf. Last week, Americans were offered the chance to fear something they probably hadn't worried about for a while: contracting HIV through a blood transfusion.
Recent advances in testing have shrunk the chances to a number almost too small to measure, but Florida Blood Services announced last week that it had failed to detect a donor who had HIV. Two blood recipients were infected.
On Friday, FBS received at least 200 calls from worried recipients and people about to enter the hospital. By 5 p.m., the center's medical director, Dr. German Leparc, had spoken to news outlets around the country, assuaging a nervous public and assuring it the blood supply was safe and that contracting HIV from a transfusion was less likely than getting hit by lightning.
But as other recent scares have shown, the level of the public's fear is not necessarily in proportion to how afraid the public should be. The sometimes-mammoth disconnect between actual risk and perceived risk can influence public policy and affect how wisely or unwisely America spends money on medical tests, hazardous waste cleanups or security, experts say.
Coincidentally, the blood banking industry is about to engage in a debate on that very issue. Next month, the U.S. Food and Drug Administration will hold a workshop on an experimental treatment that can cleanse donated blood of most diseases, including HIV.
But it also would double, maybe even triple, the cost of processing that blood, with only a minuscule increase in safety.
The FDA figures the risk of HIV infection from a blood transfusion at 1 in 2-million, although in practice the risk has been much smaller. By contrast, the risk of dying of heart disease is 1 in 385; of dying of cancer, about 1 in 500; and of dying during childbirth, about 1 in 10,000. Coronary bypass patients have a 1-in-40 chance of never leaving the hospital.
Consider the Americans who need a blood transfusion: Nearly 4.5-million would die each year without one, and half of those who get a transfusion die of their underlying illness within two years anyway. Given that, experts say, 1 in 2-million seems a very acceptable risk indeed.
Others argue peace of mind may be worth the extra cost. People who are afraid make dangerous decisions, said David Ropeik, director of risk communication at Harvard University's Center for Risk Analysis. They drive instead of fly. They leave their seat belt unfastened so they won't be trapped if their car plunges into Tampa Bay. They don't get a blood transfusion when they need one.
Scientists have studied why people happily eat fatty foods or puff away on cigarettes -- known risk factors that kill thousands of people a day -- yet blanche at other less likely risks, like getting sick from a blood transfusion. It's a matter of control, and familiarity.
Ropeik likes to compare studies of attitudes toward mad cow disease in England and Germany last year. After Germany's first outbreak infected 26 cows, and zero humans, 85 percent of people polled said the disease was a major threat to public health.
But in Britain, where mad cow was old hat and had infected thousands of cattle and killed 110 people, only 40 percent saw it as a major threat.
As for control, Dr. Raymond Harbison, a toxicologist and risk assessment expert at the University of South Florida, says what we do to ourselves is okay. What others do to us is not.
"The idea is that all other risks are unacceptable other than those I choose to assume or accept myself. And that's not a reasonable assessment of risk," Harbison said. "The major problem people have is this idea of violating their person, of putting something into them that they did not choose to be there."
Consider hazardous waste: Ropeik noted that America spends billions of dollars each year on cleaning up old plant sites and dumps, but spends less than $1-billion on smoking prevention, which kills more than 400,000 people each year.
From a public health perspective -- unless you live next to the dump -- that does not make sense. But it happens because "Americans are freaked out by hazardous waste," he said.
"If you and I and all our neighbors are freaked out about a risk that we think is big, but it really isn't, and we get the government to spend money on it, then that money is not available for the really big risk," he said. "And then we're in more danger."
Nationally, there have been just two known instances of undetected HIV infecting patients since American blood banks began using sophisticated nucleic acid tests in 1999. The first was in Texas, where a San Antonio man was infected during surgery in 2000. The other was here.
Because of the breach, Florida Blood Services is under investigation by the FDA and the state Department of Health, although the center says it followed proper procedures and all of the donor's blood has been accounted for.
Nationally, about 14-million units of whole blood are donated each year by about 8-million people, the American Association of Blood Banks says. About 4.5-million patients get transfusions each year, and most get multiple transfusions of multiple units.
"The risk of infection from transfusion is one of the smallest risks when compared to almost any other medical procedure in a hospital," said Dr. Celso Bianco, executive vice president of America's Blood Banks, an association of all non-Red Cross blood centers, including FBS.
America's expectations about the safety of its blood supply have risen quickly. Just 20 years ago, before the first rudimentary tests were developed in 1985, the risk of contracting HIV from a blood transfusion was as high as 1 percent, or 1 in 100.
By the early 1990s, the risk was cut to about 1 in 100,000, then 1 in 250,000, Bianco said.
In December 1994, FDA Commissioner David Kessler sponsored a conference called "Closing the Window on HIV." Nucleic acid tests that could find tiny bits of virus were being used in labs, and Kessler encouraged the development of larger, more efficient versions for widespread screening of blood at collection centers.
The push worked, and most blood centers had them by 1999. But as experts found themselves explaining last week, the test isn't perfect. If someone is infected up to 10 days before giving blood, there might not be enough virus in the donor's bloodstream to be detected.
Blood banks and researchers readily acknowledge they could do even more. Blood centers, including Florida Blood Services, are testing new equipment that cleans most pathogens or viruses, including HIV, from donated blood, reducing the risk even further.
Unfortunately, the process also damages the blood, meaning more blood would be needed. And it also is likely to increase the cost of processing a unit of blood by two or three times.
At a conference on blood quality in Chicago this month, Don Doddridge, chief executive of Florida Blood Services, said he learned the cost of processing one unit of blood would jump by at least $200, bringing the cost to hospitals to about $360 per unit. Other experts generally agree with that assessment.
Multiply that increase by the 14-million units donated each year, and the cost of extra safety could hit $2.8-billion annually.
To prevent one case of HIV a year? One case every two years?
"If you have to double the cost of blood to catch that one case, it's an extremely high cost per yield," said Dr. Michael Busch, vice president for research at Blood Systems in San Francisco, California's second-largest consortium of blood banks.
Dr. Karen M. Kuntz, an associate professor of decision science at Harvard who advises policymakers on the cost-effectiveness of medical technology, puts it succinctly: "Not a good use of resources," she said. "A lot of money to spend to save those life years."
When Kuntz evaluates whether something, such as safer blood, is a good deal or not, she speaks in terms of price per life years, the cost of keeping one person alive one year longer.
For a surgery to bypass three clogged arteries, it's about $20,000 per life year gained.
For the proposed blood cleansing treatment, she figures it would be at least $5-million per life year gained.
Crass as it sounds, we make that cost-benefit calculation all the time with car safety, food safety, water safety and airplane safety. As with those things, it will likely be left to the government to determine whether the benefits of newer blood treatments outweigh the costs.
In this case, it will be the FDA, which, after seeing the nucleic acid test in action for three years, has made it the standard.
The cost of that test, by the way, is about $10 per unit of blood, an overall increase of about $140-million a year. A paltry sum compared with what the next installment on peace of mind may be.
"On one hand, it seems like we should be rational and use (hard) numbers, and that should be the end of the story," Ropeik said. "But 1 in 2-million doesn't mean anything to you if you could be the one."
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