April 20, 2001 -- Pam Dewalt was infected with the HIV virus in 1981 at the age of 21, but she didn't know it for 11 years. During that time she was frequently sick and once even spent three weeks in the hospital for evaluation of her illness. Her doctors told her she probably had lupus or leukemia, and then changed the diagnosis to a viral infection.
She wasn't tested for AIDS until four years after the hospital stay, when Dewalt demanded that her gynecologist do so.
"Before that, I was told I didn't need to be tested because I didn't fit into any of the AIDS risk groups," Dewalt tells WebMD. "I wasn't promiscuous or an intravenous drug user, so they said it wasn't necessary. By the time I was tested, I had full-blown AIDS and a T cell count below 100." Normally, levels of T cells -- an important immune system cell -- are over 1,000 in healthy people.
Dewalt, it turns out, was infected by her then-fiancé, who hadn't told her he was bisexual. And even though she acquired HIV early in the AIDS era, her story remains quite relevant today. A newly released CDC study finds that many heterosexuals who are at risk for AIDS don't perceive themselves to be. And many HIV-positive heterosexuals do not tell their sexual partners they are infected.
There has been a steady rise in heterosexual HIV infections in the U.S. during the past 15 years. Such transmissions accounted for 2% of new infections in 1985 and 15% in 1999.
"There is an epidemic of heterosexual AIDS transmissions, but it does not appear to be evenly distributed throughout the population," study author R. Monina Klevens, DDS, tells WebMD. "There are groups who are clearly at higher risk for heterosexual transmission, but that doesn't mean that if you don't fall into one of these groups you are safe."
The latest CDC figures suggest that about 10% -- or 80,000 of the roughly 800,000 HIV-positive people living in the U.S. -- were infected through heterosexual contact, with about 65% of transmissions occurring from infected males to uninfected females, and 35% from infected females to uninfected males.
Klevens and some CDC colleagues interviewed almost 600 adult AIDS patients who were infected through sexual contact with a person of the opposite sex. They reported their findings in the May issue of the American Journal of Preventive Medicine. Only 35% of men and 56% of women were aware their partners had HIV. It's critical to note, though, that approximately 80% of those interviewed said they were aware their sex partner engaged in high-risk behaviors, such as intravenous drug use or male-to-male sex.
About 20% of the patients reported their partners had no known primary risk factors for HIV infection. Although that number is still significant, Klevens says this finding suggests the incidence of so-called "secondary" HIV transmissions may actually be smaller than had been feared. Secondary transmission refers to the infection of a low-risk person by another person who also has no known risk factors for HIV.
"It is at most 20% [of heterosexual transmissions] and probably smaller than that," she says. "There is a very positive message here. We conducted this study because we wanted to see if there was a potential explosion of secondary transmissions in this country, and our finding suggest this isn't happening."
But she quickly adds that heterosexuals with any risk factors for AIDS, including having sex with multiple partners, need to know their HIV status. The CDC estimates that one-fourth of the 800,000 to one million people in the U.S. infected with HIV do not know they are positive.
Jeffrey Lawrence, MD, scientific director for The American Foundation for AIDS Research, says the new AIDS drugs that are keeping HIV-positive people alive and healthy may also be fostering a sense of complacency among some about protecting against its transmission.
"The city of San Francisco recently reported a doubling of HIV infections among young gay males between the ages of 15 and 19, and they attribute it to lack of fear [of HIV] given the existence of effective treatments," Lawrence tells WebMD. "Good surveys haven't really been done among heterosexuals, but I suspect that if young gay men are thinking this way, then certainly so are adolescent heterosexuals who feel invulnerable anyway."
Pam Dewalt, who works with the California-based HIV support group Women at Risk, says she frequently talks to young people about protecting themselves from HIV. In her 20th year of HIV infection, the Culver City, Calif. woman says the drugs that keep her alive have also left her with disfiguring fat distributions in her back and abdomen.
"People think they don't have to be as safe because if they get infected they just have to take a few drugs," she says. "What they don't realize is how debilitating the drugs can be and how life changing they are."