Potential home HIV test ("OraQuick") turns up 25% false positives in SF

Promising HIV test turns up false positives in SF

Associated Press

SAN FRANCISCO - A promising new oral HIV test that uses fluid swabbed from the mouth to quickly and easily detect the virus that causes AIDS incorrectly diagnosed a quarter of the people who tested positive in San Francisco, city health officials found.

Forty-seven people who tested positive after using the OraQuick Advance HIV test in city clinics were not infected at all, the San Francisco Department of Public Health said this week.

Investigators learned of the errors after follow-up blood screenings gave the patients a clean bill of health, and health officials stopped using the test at City Clinic, the health department's primary testing location for HIV.

At the same time, the U.S. Food and Drug Administration, which approved the OraQuick test for professional use last year, is now considering a request from drug maker Orasure Technologies, of Bethlehem, Pa., to approve it for home use and over-the-counter sales. "We need to vigorously look at this," said Jeffrey Klausner, San Francisco's director of sexually transmitted disease prevention and control services. "You wouldn't want to have a home test with this problem."

http://www.mercurynews.com/mld/mercurynews/news/breaking_news/13369449.htm

I just wonder if somebody had a false positive and, in a state of depression over the result, took their own life. goddamn but our government is irresponsible with people's lives.

I'd much rather a person have a nearly 100 percent reliable test and the results given by someone capable of doing counseling. Despite 20+ years of HIV, there are still so many misconceptions about the disease that could be better handled by a professional able to explain exactly what the the test results mean and what their next step should be. Also, I fear that someone is likely to get a positive test at home and do something rash like suicide or assume their significant other is cheating and gave them HIV and kill them.

as a way of telling somebody, "Something might be going on, and you need to get in for a quick blood test to find out what." A cheap, discreet, in home test might do just that, rather than have people live in total denial, avoiding doctors and lab tests.

I know there was a high false positive rate for the old HIV antibody tests, especially among people with autoimmune diseases like systemic lupus and Sjogren's syndrome. The more expensive tests weeded out the false positives, but at the time were too expensive to do as a first test on everybody who came through the door.

False negatives would be a much bigger concern, IMO, giving people a false sense of security and spreading the disease more widely.

Any such test is going to have some rate of "false positives" and "false negatives" ,,, and the impact of these erroneous results is going to be completely different.

First, lets get the number straight. From what I can extract from the story, the number of "positives" was 188 ... of which 25% or 47 were "false positives." That means 141 people with HIV were correctly tested - along with possibly thousands without HIV! The article states "there are no known instances in which the test missed an HIV infection that a traditional blood screening would have caught." That implies that there were no "false negatives."

In terms of "abundance of caution," the impact of a 'false negative' is of far greater concern since the testee may not seek care that would prolong his or her life. The impact of a 'false positive' is that the person may seek medical advice and find out they're OK. That's not "bad" - just inefficient.

If the test is properly marketed and labeled, it would say "seek further medical consultation if the results of this test are positive" then it's fulfilling a decent screening need - acting as a first stage of a societal triage and effectively separating those who don't require further medical testing from those who do. If the rate of infection in the population at large is 6% then 8% will test positive ... but the 92% who test negative (with apparrent reliability) won't be uselessly burdening the health care infrastructure. That is, after all, the most pragmatic rationale for such "home testing."

Who, in their right minds, would expect some inexpensive home test kit to be a complete substitute for more extensive medical diagnosis? If it were that easy, why the fuck would blood testing be necessary at all?

tests be presented to the client as a "preliminary positive" and be confirmed with a follow up test and that two step process be explained to the client before performing a test (commonly called the "rapid test" - a result is returned in 20 minutes)...our county runs a follow-up test in the lab on a serum sample for confirmation.

I hope SF figures out what triggered those OraQuick tests in uninfected people...and that people continue to have other testing options if they're uncomfortable with OraQuick (that's a standard for client choice in most CA HIV testing programs).

(on edit) OA = Office of AIDS, CA Dept. of Health Services

I haven't a clue how difficult it would be for me to get a discrete AIDS test here but I suspect it would be fairly difficult. This would be very useful for me if I ended up needing a quick discrete test for some reason. Then, if I got a positive I could make arrangements to travel to Charolette or Raleigh for a better test.