New York City sexually transmitted infection clinics have stopped have stopped using oral fluid with OraSure Technologies' OraQuick Advance Rapid HIV 1/2 Antibody Test because of an increased rate of false positives, Bloomberg reports. According to city health officials, the rate of false positives from the test rose as high as 1.1% -- or about five times higher than the kit's label claims -- over the past eight months (Lauerman, Bloomberg, 6/16). In a statement, the New York City Department of Health and Mental Hygiene said its STI clinics have switched to OraSure's OraQuick ADVANCE Rapid HIV Test that screens blood (Health department release, 6/18).

The OraQuick oral test requires users to swab their gums and then place the swab in a holder. After 20 minutes, one line appears on the strip if the test result is negative and the person is HIV-negative, and two appear if the result is positive and the person is HIV-positive. Positive results require a follow-up test with a medical professional for confirmation. The test initially was provided in the city in response to the number of new AIDS diagnoses among people ages 13 to 26, which increased by 6% in 2006. In addition, about one-third of people tested for HIV at public health clinics with other tests do not return for the results, according to CDC (Kaiser Daily HIV/AIDS Report, 4/1).

Susan Blank, city commissioner for STI prevention and control, said that although the test meets U.S. standards and is still on the market, the city's 10 STI clinics stopped using it to screen oral fluid for HIV on May 27. Health officials started noticing problems in October 2007, and they continued through April, Blank said. She added that although test results returned to normal in May, the city's clinics stopped using the tests. "So far, false positives have not been linked to handling, storage conditions, lot numbers, clinic sites and test operators," Blank said.

According to OraSure spokesperson Ron Ticho, the oral test kit has performed better in other cities. He added that in more than 250,000 tests over the past 17 months at 400 sites in the U.S., the test had a 0.2% false positive rate. "What's happening in New York City appears to be a slight aberration," Ticho said Monday, adding, "Performance results may fall slightly outside the expected range for a short period of time. That's expected." Ticho noted that Orasure is following standard company procedure for investigating product performance and is cooperating with CDC and New York officials to understand the issue.

Bernard Branson, associate director for laboratory diagnostics at CDC's Division of HIV/AIDS Prevention, said the agency is investigating whether health officials in other cities are experiencing similar problems with the oral tests. New York -- as well as health departments in San Francisco, Minnesota and Utah -- recorded similar elevated rates of false positives with the test in 2004 and 2005, according to Bloomberg.

Branson added that Blank has filed a report with CDC and that the agency is considering publishing a notice in its Morbidity and Mortality Weekly Report. "When oral testing showed low numbers of false positives, that reassured everyone," Branson said, adding, "When that changes, people need to find out what the problem is and get to the bottom of it" (Bloomberg, 6/16).