A New Era in HIV Testing

The Centers for Disease Control and Prevention is about to change its recommendations for HIV antibody testing. In the past testing was recommended for people in high-risk groups or those with exposure risk. Testing involved extensive pre- and post-test counseling and formal written consent. These components of HIV testing originated in the era before combination therapy, when HIV was highly stigmatized and little could be offered for hope or treatment. At that time it was important to establish before testing that a patient would be emotionally capable of hearing that he or she was HIV-positive. Patients also needed to understand that they might lose insurance, employment, or housing if their positive serostatus became public. With that era gone, the only issue left for medical professionals was the burden of pre- and post-test counseling. This requirement often made it difficult for primary care offices to routinely include HIV testing during checkups, since many practitioners didn't feel comfortable explaining the intricacies and implications of a positive serostatus. Nor did they have the time. With the newly proposed CDC guidelines, consent can be oral and the counseling less extensive. Equally helpful is the labeling of HIV testing as 'routine.' This means physicians and patients can be as comfortable checking for HIV as for diabetes or elevated cholesterol. No more profiling who should be tested. This last aspect is important because it is estimated that about 25% of people who are HIV-positive in this country have yet to be tested, so they do not know they have the virus. That amounts to between 252,000 and 312,000 people. And the CDC estimates that unidentified seropositives are responsible for about 50% of new infections. Studies have shown that when people know they are seropositive, their participation in unsafe sex drops by 68%. In a study of gay men in five U.S. cities, 25% were found to be HIV-positive, 48% of whom were unaware of their serostatus. Further analysis showed that 46% of the black men studied were HIV-positive, and 67% did not know it. This correlates with the difficulties in getting HIV discussed among African-Americans, who now account for half of all new infections and more than a third of cumulative AIDS deaths in this country. Perhaps the new CDC guidelines can start to reverse this disproportionate spread of HIV. Early detection of HIV also leads to other benefits. Currently, about 45% of people who test positive for HIV do so less than 12 months before progressing to AIDS. This means the best window of opportunity for antivirals to be both well-tolerated and successful in rebuilding the immune system is missed almost half the time. Here we clearly need to get the message out about testing. Earlier testing can also catch the recent seroconverters, who often have high viral loads. It is estimated that 30% of HIV transmissions originate from people who have seroconverted within the prior three months. The best news in all of this is the development of new rapid HIV tests. The gold standard has been an ELISA antibody test on blood sent to a standard lab. If the ELISA is positive, results are confirmed by a second test called a Western Blot. Results of these tests took anywhere from a few days to several weeks to come back, and often patients did not return for them. Now there are 20-minute office tests. Two of them test blood obtained by finger stick, and one, from OraQuick, tests a swab of saliva. In New York testing rates have risen 30% since the introduction of OraQuick. OraQuick was in the news at the end of last year, when several testing sites reported higher than expected numbers of false positives. But when investigated by the CDC, the test was shown to have 99.6% specificity, and similar false-positive rates were not discovered in other testing sites. When it comes to HIV, knowledge is power, and ignorance is not bliss. Bowers is board-certified in family practice and is a senior partner with Pacific Oaks Medical Group, one of the largest U.S. practices devoted to HIV care. E-mail him at dan@hivplusmag.com.