HIV is a very deceptive virus. One way in which it is so insidious is that once it enters a human body, it can take the body several weeks to develop enough antibodies for the infection to show up on most existing HIV tests today. That also just happens to coincide with one of the periods in the virus’ life cycle in which the newly infected person is most infectious and capable of passing it on to others through unsafe sex. Once the body produces enough anti-bodies to show up on a typical HIV test, it also has, ironically, begun to fight off the virus enough so that the individual is somewhat less capable of passing it on to others — although even then that risk is still very far from zero. What that means is that between the time of initial infection and the buildup of antibodies, that person is at one of his most infectious stages in the disease and if he is tested, his test result would likely still be negative during that early period.
There are tests known as nucleic acid testing (NAT) which can detect the presence of the virus itself, but they aren’t routinely used because of their high false-positive rate. But a study published in the June 15 issue of the Annals of Internal Medicine found that adding NAT testing to the current antibody-based rapid HIV testing that is commonly in use can increase detection of HIV by 23%. Yesterday, the Food and Drug Administration announced the approval of the first HIV test to detect both the antibodies and the HIV virus itself. According to a statement from the FDA:
“The approval of this assay represents an advancement in our ability to better diagnose HIV infection in diagnostic settings where nucleic acid testing to detect the virus itself is not routinely used,” said Karen Midthun, M.D., acting director of FDA’s Center for Biologics Evaluation and Research. “It provides for more sensitive detection of recent HIV infections compared with antibody tests alone.”
The test was developed by Abbott Laboratories. The separate study published in the Annals of Internal Medicine, which appears to be unrelated to the FDA announcement, was funded by the National Institutes of Health, University of California at San Diego, and the California HIV/AIDS Research Program.