American Association for Clinical Chemistry
Better health through laboratory medicine
March 2008 Clinical Laboratory News: Study Highlights Success of Community-Based Rapid HIV Testing

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March 2008: Volume 34, Number 3

Study Highlights Success of Community-Based Rapid HIV Testing
by Deborah Levenson

A cover story in the October 2007 CLN, “The Challenges of Universal HIV Screening,” highlighted the difficulties of implementing a 2006 Centers for Disease Control and Prevention (CDC) recommendation that calls upon healthcare providers in all settings to screen patients ages 13–64 for HIV and suggests that those at high risk be screened at least once a year. That story noted that most HIV screening occurs in traditional healthcare settings, including hospitals. Now new research shows that rapid HIV testing in settings outside medical offices and other health facilities can effectively screen people from groups at high risk of contracting the infection.

A team of researchers from the CDC and community-based organizations in eight major cities has shown that rapid assays administered in mobile units stationed in places where high-risk people congregate—followed by confirmatory testing—identifies newly diagnosed infections at a rate of 1%. (Morbidity and Mortality Weekly Report 2008; 56: 280–282).

That figure is comparable to the rate of positive test results reported at other CDC-supported HIV testing and counseling sites, noted the team from CDC and organizations in Boston, Mass., Chicago, Ill. Detroit, Mich., Kansas City, Mo., Los Angeles, Calif., and Washington, D.C. Their organizations provided rapid testing to 23,900 people—30% of whom had not been tested previously for HIV—and newly diagnosed 267 people with infections.

Trained staff offered Oraquick Rapid HIV-1 Antibody Test or Oraquick Advance Rapid HIV-1/2 Antibody Test (Orasure Technologies, Bethlehem, Pa.) on either oral-fluid or whole-blood specimens and provided results within 20–40 minutes. They counseled clients from mobile units stationed in parks, shelters, hotels, clubs, health fairs, syringe exchange sites, and community clinics. Of the clients who received tests, 39% were non-Hispanic blacks and 31% were non-Hispanic whites. Forty percent had not seen a healthcare provider during the preceding year, and 9% were homeless, the clients reported.

When results were positive, the community organization staff collected either oral- fluid or whole-blood specimens for confirmatory Western blot testing and scheduled a follow-up appointment to give the client the results. Staff referred clients who received HIV positive results to clinics and other local health care providers.

A total of 331 clients had a positive result on a rapid HIV screening test, while 286 of them received a confirmatory test. Of those 286 people, 267, had confirmed HIV infections, but only 75% returned to receive their results. Six previous studies of rapid HIV studies report that clients received confirmatory results at similar rates, the researchers noted.

The team suggested two strategies for increasing the rate at which clients who had positive results on the rapid test learn their true HIV status after confirmatory testing. One involves referring clients with positive results on screening tests to immediate medical care rather than making them wait and return to the initial testing site to get results of confirmatory testing. The other employs a combination of rapid HIV tests so clients can receive both preliminary and confirmatory results and be linked to health care services on the same day.

CDC is now evaluating a confirmatory algorithm that uses a combination of rapid tests. “However, until this strategy can be validated, preliminary positive tests should always be confirmed with Western blot tests,” the researchers wrote.