People who want to know whether they have the AIDS virus but are afraid of blood tests now can opt for an oral exam that's just as reliable.
The Food and Drug Administration approved Epitope Inc.'s new Orasure Monday, which analyzes cells scraped from a person's mouth to detect HIV, the virus that causes AIDS.Unlike an earlier, less sensitive version of Orasure, the new test does not require that patients have blood drawn to prove they are infected.
Also Monday, the FDA approved a separate test to tell people who have HIV how much of the virus is floating in their blood-streams. People with high amounts of HIV in their blood are most at risk of getting sick fast.
Hoffman-La Roche will offer its Amplicor test free to any HIV-infected patient for 60 days starting June 17. Later, the test will cost $150 to $200.
The question is whether patients will want to know the prognosis, said Dr. Curtis Scribner, FDA's deputy director of blood research. He said studies show that patients with high HIV blood levels are more likely to get sick fast, but nobody knows if drugs that lower those levels significantly reduce the risk of death or even if changes in HIV amounts signal it's time to change treatments.
"We are at the cutting edge of science and medicine right here," Scribner said. "We just have not answered those questions yet."
Doctors now gauge AIDS progression by measuring levels of an immune cell called CD4 that is a main target of HIV. But some people have no AIDS symptoms despite very low CD4 levels.
But the new-and-improved Orasure could significantly help public health, by serving people at risk of HIV who have shunned blood tests, Scribner said.
Health workers also won't run the risk of sticking themselves with the needle they just used on a possibly infected patient, explained Donna Sturgess of SmithKline Beecham, which will sell the new Orasure.
Orasure uses a treated cotton pad to scrape a tissue sample from between the gum and cheek. The sample is tested for antibodies to HIV.
A first-generation Orasure was approved in 1994, but it used a less sensitive method to screen for HIV antibodies, meaning people who tested positive still had to have their blood tested to confirm they had the deadly virus.
The new Orasure allows this confirmatory testing, called Western blot testing, on the oral sample instead of on blood. Clinical trials showed the Orasure Western blot test was 99.9 percent as accurate as the traditional blood test.
It will cost about the same as a blood test, which averages about $50-$60, and doctors will receive the results within three days, Sturgess said.
Orasure is supposed to be used only by health-care providers, but SmithKline and Epitope are seeking FDA approval for a similar home test.