Many public-health officials see the HIV ribonucleic acid (RNA) test, which can detect new infections within a week to 10 days, as an important HIV prevention tool. Studies suggest 10% to 50% of new infections are transmitted by the recently infected, and although rapid antibody tests can provide immediate results, the RNA test is singularly capable of detecting the newest infections, during the primary or acute phase.

RELATED ARTICLES
New Test Helped Identify HIV Outbreak
Study Examines Detection of Acute Infections
New Automated Rapid HIV Test Available

“People with acute infection have more virus in the blood, and if they’re unaware they’re infected, they’re more likely to engage in risky behavior,” Kenneth Mayer, a professor of medicine at Brown University and a leading AIDS researcher, told The New York Times. Early intervention and counseling can help prevent the recently HIV-infected from transmitting the virus to their partners, he said.

However, the RNA test is not widely used, in part because it is expensive, involves drawing blood and complicated laboratory work, and does not provide immediate results. Antibody tests form the nation’s backbone for diagnosing HIV infections, though the Centers for Disease Control and Prevention has conducted pilot RNA testing in some cities.

Health departments in North Carolina and San Francisco have been using RNA testing for several years, reducing the cost by pooling blood samples from multiple people for testing. Officials there advocate wider use of RNA testing, after having found dozens of acute infections that went undetected by standard antibody tests.

“Early detection is a prevention strategy,” said Judy Auerbach, public policy director of the San Francisco AIDS Foundation, which runs the Magnet health clinic in the city’s Castro district. Since last year, Magnet has offered RNA testing to high-risk gay men.

The CDC recently began a comparative study involving an advanced antibody-antigen HIV test that can detect 85% of acute infections picked up by RNA testing. The newer test is easier to administer and could become commercially available next year, CDC officials said.