You pretty much know the facts when it comes to HIV, right? Well, you might be falsely confident: A study of almost 2,000 people published in BMC Public Health found that almost half had incorrect knowledge about HIV transmission and AIDS. Worse, men were more likely than women to have the wrong info.
The upshot? It’s time to re-familiarize yourself with the virus.
In short, HIV can be dangerous because it attacks the immune system hard. “HIV kills a particular kind of immune cell called CD4 T cells, which, once it’s killed enough of them, makes us vulnerable to getting infections and cancers,” says Stacey Rizza, MD, an infectious disease specialist at Mayo Clinic.
Left untreated, HIV can progress into AIDS. The disease is something we should all have a solid understanding of, too, since anyone can get it. Here are six things you didn’t know about your risk of transmission.
1. HIV Does Not Discriminate
Though gay and bisexual men do have the largest number of new HIV diagnoses in the United States, anyone can be infected with the virus — women, older people, and heterosexual people included, notes Rizza.“It’s still very common, unfortunately, in men who have sex with men, and that population continues to be at the highest risk for HIV,” she says. “But essentially, everybody else is at risk as well.”
That’s why Rizza suggests always using condoms — and if you reach a point of monogamy in a relationship, make sure you and your partner are tested for HIV (and show each other the results) before deciding whether or not to stop using protection.
2. Just Because You Don’t Have Symptoms Doesn’t Mean You’re HIV-negative
Don’t feel sick? Many people with HIV don’t. “Most people who get HIV may have what feels like a viral illness at the beginning, kind of like the flu or a cold; others feel nothing at all,” Rizza says. “People can live with HIV for years or even decades with no knowledge that they’ve been infected.”
That’s why it’s incredibly important to get tested. The Centers for Disease Control and Prevention (CDC) recommends that everyone ages 13 to 64 get tested for HIV at least once in their life and that sexually active gay or bisexual men could benefit from more frequent testing—once a year if you have any risk factors.
3. If You’re High Risk, You Can Take Measures to Lower Your Risk
If you’re at a high risk of getting HIV (say, you’re in a relationship with someone with HIV), something called pre-exposure prophylaxis (PrEP) — taking two HIV medicines together as pills every day — can dramatically decrease your chance of getting HIV, Rizza says. PrEP essentially stops HIV from spreading throughout your body. When taken regularly, it’s effective, sinking your risk of getting HIV via sex by more than 90 percent. Check out the risk factors that make you a candidate for PrEP here.
4. Being Circumcised Lowers Your Risk of Getting HIV
A little bit of science: In order for HIV to enter a cell, you need two special receptors: a CD4 receptor and a chemokine receptor, either CCR5 or CXCR4, Rizza explains. And of all the trillions of cells in your body, only certain cell types have those receptors. One is called dendritic cells.
“The foreskin of the penis is particularly heavy in dendritic cells, so if you have a foreskin, you’ve got more of the type of cells that can become infected and grab onto HIV,” she says. The largest group of uncircumcised men at an elevated risk of contracting HIV is heterosexual men in developing countries.
5. If You (or Your Partner) Has Another STI, Your Risk Goes Up
Having another STI (such a gonorrhea, chlamydia, syphilis, HPV, or herpes) makes it more likely to both get HIV if you come into contact with the virus and transmit it if you have it already. “Any kind of breakdown in the mucosa or skin can make it more vulnerable for the virus to get in,” says Rizza. Even if you don’t have any visible sores or symptoms, STIs can increase inflammation, upping the number of cells that HIV can target. If you’re HIV-positive? Your risk of infecting someone else seems to go up because of an increased concentration of HIV in both semen and genital fluids.
6. You Can Get HIV from More Than Just Sex
Anal and vaginal sex are two of the main ways that HIV is transmitted, says Rizza. But they’re not the only ways. Sharing a spoon, sharing a toilet seat, handshaking, or kissing will not transmit HIV, but any kind of blood or body fluid that’s transmitted technically can, she says. That means transmission via tattoos, sharing needles, oral sex, and even from mother to child is possible, though risk is much lower, she notes. “Anal intercourse is the highest risk, vaginal intercourse is next, and then oral is the least likely,” she notes.
The CDC says there are no known cases of anyone getting HIV from a tattoo in the U.S., but it’s still important to take precautions. “If people get tattoos, we recommend they go to a parlor where all of the dye is thrown out between people and all of the tubing is autoclaved and the needle is changed,” says Rizza.