When the National Enquirer broke the news of Charlie Sheen's HIV diagnosis, the story was already misleading: "Charlie Sheen AIDS Cover-Up," blared the headline.

Credit: Getty Images

When the National Enquirer broke the news of Charlie Sheen’s HIV diagnosis, the story was already misleading: “Charlie Sheen AIDS Cover-Up,” blared the headline.

Sheen responded with an exclusive TODAY show interview, where he revealed his HIV-positive diagnosis. Note: Sheen has HIV (human immunodeficiency virus), not AIDS (acquired immunodeficiency syndrome). AIDS is the last stage of HIV infection (characterized by a weakened immune system), and not everyone with the virus will develop it.

That’s just one of the misconceptions people have about HIV, which affects more than 1.2 million people in the United States, according to the Centers for Disease Control and Prevention.

“A lot of the myths that are still out there are the ones that were there in the 1980s,” says James Kublin, MD, the executive director of the HIV Vaccine Trials Network (HVTN), based at Fred Hutchinson Cancer Research Center in Seattle. Here are seven things you should know about HIV.

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MYTH: Very few people in the U.S. get HIV anymore

The number of people in the U.S. who get HIV each year is surprisingly high, and that rate is by no means plummeting. In fact, the number of people who are infected annually with the virus has remained relatively stable—at about 50,000—for the past decade. (In 2009, the CDC estimated that 17.4 people per 100,000 were infected with HIV; in 2013, that number was 15 in 100,000.)

MYTH: HIV/AIDS awareness is high

Our awareness of it actually might be at one of its lower points. One possible explanation: There’s been a lot of progress with how we treat HIV. Since the discovery of the virus and its link to AIDS in the 1980s, people with HIV are living longer, healthier lives.

Thirty years ago, acquiring the virus could have been fatal within a year, says Larry Corey, MD, a principal investigator for the HIV Vaccine Trials Network at the Fred Hutchinson Cancer Research Center. Now people can live with it for 40 or 50 years. One 2013 study in the journal PLOS ONE found that an HIV-positive 20-year-old in the U.S. or Canada on antiretroviral therapy can expect to live into their early 70s—almost as high as the rest of the population.

But that success might be having an unintended side effect: We’re not as aware of it as we once were. Dr. Kublin did an internship in the 1980s at St. Vincent’s Hospital, referred to as the epicenter of New York City’s AIDs epidemic. “In New York City in the late ‘80s, [these deaths] were on the front pages of the newspapers,” he says. Now, only 14% of Americans have seen, heard, or read “a lot” about the problem of AIDS in the United States in 2013, down from 34% in 2004, according to a Kaiser Family Foundation poll. (Plus, 15% of Americans haven’t heard anything about AIDS in the U.S. in the past year; 41% said they only heard “a little.”)

MYTH: Most people with HIV get diagnosed right away

Here's an alarming stat: 1 in 8 people who have HIV don't realize it, according to the CDC. And people aged 13 to 24 make up about 26% of all new HIV infections in the U.S. (Young gay and bisexual men are especially at risk: They make up about 19% of all new HIV infections, and 72% of youth HIV infections.) But 44% of young adults (aged 18-29) say they aren’t personally concerned about being infected with HIV, according to the Kaiser Family Foundation poll, while another 28% say they aren’t “too concerned.” And despite all the advances in HIV treatments—antiretroviral drugs, condoms, behavioral therapy—if people don’t know they have the virus, they can transmit it to others, says Dr. Corey.

MYTH: You can get HIV from a mosquito bite

This longstanding myth is one that won’t seem to go away. According to the CDC, there’s no evidence that it's possible to contract HIV from a mosquito. “The virus doesn’t survive in the mosquito, and doesn’t live in the spit,” says Dr. Kublin.

MYTH: You can catch HIV from sharing a drinking glass

About 1 in 4 Americans believe that you can contract HIV by sharing a glass—a number that’s barely changed since 1987, according to the Kaiser Family Foundation poll. Another 17% believed you can get HIV from touching a toilet seat (also false); that’s another percentage that hasn’t fallen since the late 1980s.

For the record: HIV is mainly spread through sex (anal sex has the highest risk, and vaginal sex has the second-highest) or sharing needles, according to the CDC.

MYTH: HIV is a man's disease

Women make up about 1 in 5 new HIV infections each year. Men who have sex with men account for about 63% of all new infections—but 84% of women who get HIV are thought to get it by having sex with men, while another 16% will acquire it from sharing a needle for drug use. African-American women have a higher risk: About 5,300 black heterosexual women were estimated to get HIV in 2010 compared to 1,300 white heterosexual women and 1,200 heterosexual Hispanic or Latino women.

MYTH: If you get HIV/AIDS, it's your own fault

Sad but true: 32% of people in the Kaiser Family Foundation poll say that if a person gets AIDS, that’s on them. And 21% say that they think AIDS is a punishment for our falling moral standards. Fewer people think that way than they did in years past, but the numbers haven’t fallen as drastically as you might think.

“There’s a misconception that [if you get HIV], you did something wrong,” says Dr. Corey. “But all infections are created by some contact with another person.”

Having more than one sexual partner is a risk factor for HIV, but it’s possible to get the virus by sleeping with just one person. And, as Dr. Corey says: Sure, you could never have sex again, but sex is a part of life.

Dr. Corey and Dr. Kublin are both working at the Fred Hutchinson Cancer Research Center to develop an HIV vaccine—the clinical trial, called HVTN 100, has been launched in South Africa.

“Solving this is important for our country, it’s important for our humanity,” says Corey.