National HIV Testing Day

There is significant documentation to show that the life expectancy of individuals testing positive for HIV is almost two and a half decades. Even for people diagnosed at later stages of AIDS, current treatments are providing them with as much as an additional fifteen years of life. This alone is cause to celebrate. This is a much different picture from what was seen in the beginning of the epidemic when hearing the news that being HIV positive was the same thing as a death sentence.

Wednesday, June 27, 2007, will be lucky thirteen for National HIV Testing Day. There will be a national “push” for people to find out their HIV status. As always, testing remains free and will be available at many sites around San Diego County. This is a perfect time for medical professionals to remind their patients to get tested. Since the beginning of the epidemic locally, over 13,000 men, women, and children have been diagnosed with AIDS. Currently, there are approximately 15,000 individuals living with AIDS or HIV disease in the County of San Diego. Unfortunately, an additional 3,500 people do not know that they have been infected. Of those who do know that they have HIV, over 57 percent are in treatment. That still leaves 43 percent not on life-saving antiretroviral medications.

While determining or knowing one’s HIV status is not the cure-all for this epidemic, this knowledge provides the necessary information needed for patients to make informed decisions about seeking healthcare. All of the County of San Diego testing sites offer referrals to HIV specialty primary care, partner notification, and treatment options. Approximately 40 percent of new cases are spread because the infected partner did not know their HIV status. Either the individual had never been tested or had been tested during the “window period” of the disease. The available HIV tests will show that a person is HIV positive between six weeks and six months after initial infection. During the “window period,” the individual will test negative and may continue to have unsafe sex while actually being highly infectious to others.

Here at the County of San Diego, we are partnering with the Antiretroviral Center (AVRC) at UCSD Medical Center to bring Nucleic Acid Testing (NAT) to the populations most impacted by AIDS/HIV disease. This pilot program was started in February 2007. Individuals at high risk for HIV infection coming in for testing at The Center and who test negative are asked if they would like to participate in a study to determine if they are in the “window period” of the disease. If consent is given, a tube of blood is drawn and a NAT is performed. The results of the test are available within one week and are given in person to the tested individual. This highly sensitive test can determine early infection — as early as one week.

Historically, in 2002, the Food and Drug Administration (FDA) licensed the first NAT system intended for screening donors of whole blood and blood components intended for use in transfusion. The approved test system was developed by Gen-Probe Inc., San Diego, and is distributed by Chiron Corporation, Emeryville, Calif. Blood donors have been tested for evidence of HIV infection since 1985 and for evidence of HCV infection since 1990. Although increasingly sensitive tests for detection of HIV and HCV antibodies and HIV antigen were implemented during the past decade, in rare instances infections in donors had been missed.

The NAT system detects viral genes rather than antibodies or antigens (proteins from the virus). Detection of viral genes permits detection earlier in the infection since the appearance of antibodies requires time for the donor to develop an immune response, and since detection of antigens requires time for a higher level of virus to appear in the bloodstream.

This new technology detects very small amounts of genetic material by copying the genes numerous times, resulting in a billion-fold amplification of the target gene. The approved test system can detect ribonucleic acid (RNA) from HIV-1, as well as HCV. This allows for the detection of all known HIV-1 subtypes with sensitivities designed to reduce the window period of false negative results from standard HIV testing. For HIV-1, the average window period with antibody is 22 days. This window period is reduced approximately to 16 days with antigen testing and to 12 days with NAT. The NAT is currently used universally to screen blood donations for transfusion in the United States.

We are also working on a grant with AVRC to expand this program to multiple sites in the county. Since research has shown that those who know their HIV status are more likely to inform and protect their partners, it is believed that NAT testing has the potential for significant reduction in the spread of HIV. The number of lives that will be saved from HIV infection and the amount of money that will be saved from halting the spread of HIV will be evaluated by this program.

Please recommend that patients, who engage in risky sexual practices, obtain HIV testing. Patients can also contact the County of San Diego HIV Counseling and Testing Program, at (619) 296-2120, to find the sites that are offering the NAT for HIV.