American consumers may soon be able to test themselves for the virus that causes AIDS in the privacy of their own homes, after a panel of experts on Tuesday recommended approval of the first rapid, over-the-counter HIV test.

The 17 members of the Food and Drug Administration advisory panel voted unanimously that the benefits of the OraQuick HIV test outweigh its potential risks for consumers. While the test, which uses a mouth swab to return a result in 20 minutes, does not appear to be as accurate as professionally-administered diagnostics, panelists said it could provide an important way to expand HIV testing.

The FDA will make its final decision on whether to approve the product later this year, weighing the opinion of the panel.

Government officials estimate one-fifth, or about 240,000 people, of the 1.2 million HIV carriers in the U.S. are not aware they are infected. Testing is one of the chief means of slowing new infections, which have held steady at about 50,000 per year for two decades.

Based in Bethlehem, Pa., Orasure has marketed a version of OraQuick to doctors, nurses and other health care practitioners since 2004. When used by professionals, the test is shown to accurately identify both carriers and non-carriers 99 percent of the time.

But a trial conducted by the company showed the home test only correctly detected HIV in those carrying the virus 93 percent of the time. The FDA estimated the test would miss about 3,800 HIV-positive people per year, while correctly identifying 45,000, if approved for U.S. consumers. The test could prevent 4,000 new transmissions of the virus annually, though the figure could vary depending on how many people purchase the test. While it's not clear why the test was less accurate in consumer trials, company researchers said they expected the test's sensitivity to drop when used by consumers versus professionals.

Panelists stressed that the test's labeling should state that a negative reading does not automatically mean the person does not have HIV, because of imperfect results. Panelists also stressed the importance of a toll-free number to put those who test positive in touch with counseling and medical care.

Despite concerns about less-than-perfect use by the public, the panel overwhelmingly sided with more than two dozen HIV advocates and doctors, who said the test represents a step forward in combating the virus.

"Over-the-counter testing has the potential to reach a far greater number of people who want to know their HIV status on their own terms," said Tom Donohue, founder of HIV awareness group Who's Positive.

"We are always looking for game changers, and we believe this is one of them," said Carl Schmid, deputy director of the AIDS Institute. "Not only will it help reduce the number of infections but it will bring more people into care and treatment."

Tuesday's meeting was the second time in less than a week that FDA advisers recommended approval of a novel medical product to slow the spread of HIV. Last Thursday a similar panel of drug experts endorsed the HIV daily pill Truvada for preventive use. If FDA follows the group's advice, the daily medication will become the first drug approved to prevent healthy people from becoming infected with the virus.

The FDA has already approved other HIV test kits designed to be used at home, although those kits _ which require a blood sample _ must be sent to a laboratory for development. Orasure executives argue that a test that can be done at home will appeal to a much broader group of people.

FDA officials said it is impossible to predict how widely the test would be used, but it would be most effective in the hands of people at high risk of acquiring the virus, including men who have sex with men.

A recent survey of gay and bisexual men cited by public health officials found that 84 percent would test themselves more frequently if they could buy an over-the-counter HIV test.

Orasure sells its professional version of the test for $17.50, though company executives declined to discuss how they would price the consumer version.