Human immunodeficiency virus (HIV) is a virus that attacks your immune system, weakening it and making you more vulnerable to illnesses. Untreated HIV can lead to acquired immune deficiency syndrome (AIDS), a disease that occurs when your immune system is so weak that it can’t fight off illness.
HIV is still an epidemic in both the U.S. and around the world, with around 50,000 new cases of HIV occurring each year in the U.S. alone. There are many different ways you can contract HIV: through unprotected sex, by sharing needles, and, more rarely, via a blood transfusion. Your chances of contracting HIV vary depending on several factors.
Having sex with an infected person is one of the main ways HIV is spread. Because HIV is transmitted via semen, blood, and vaginal fluid, sexual contact with an infected partner greatly increases your chances of contracting HIV. However, sex with an infected person doesn’t necessarily mean you will contract HIV. If you use a condom during intercourse, your chances for contracting HIV will be reduced.
Having sex without a condom increases both partner’s chances of getting HIV. When you have unprotected sex, it is easy for semen, blood, and rectal fluid infected with HIV to enter your system. In addition, having unprotected sex places you at a greater risk for other sexually transmitted infections (STIs), making you even more vulnerable for contracting HIV.
All forms of unprotected sex—anal, vaginal, oral—leave you at risk for getting HIV. Unprotected anal sex is particularly risky, as is discussed next.
“Topping” and “bottoming” are positions in anal sex. The person topping is the one in the insertive position, while the person bottoming is in the receptive position. You can get HIV in both positions, especially during unprotected sex, but bottoming is riskier than topping. This is because the lining of the rectum is fragile and can tear easily, leaving a route for HIV-infected fluids such as semen to enter the bloodstream and body.
It is easier to contract HIV from sex with a male than from sex with a female. For females having unprotected sex with a male, the vaginal and anal membranes are much more likely to tear, leaving an easier way for HIV to invade the body. Men who have sex with men are especially at risk for contracting HIV because the rectal membrane is delicate and prone to tearing during sex.
This doesn’t mean that men can’t get HIV from having sex with women—they can. HIV is also in vaginal fluid, and any open sores on the penis can be a gateway for an infection. Also, men who are uncircumcised are more at risk than circumcised men of contracting HIV.
While women infected with HIV who have sex with other women can possibly transmit HIV through vaginal secretions and menstrual blood, there are no documented cases of females infected with HIV though sex with another female.
People with untreated STIs are more likely to contract HIV than people without STIs. Why? First, some STIs cause ulcers, or sores, in the genital area. These sores create an opening in your skin, making it easier for HIV to get into your system. Second, when you have an infection, your immune system sends certain cells called CD4+ cells to help fight the infection. These CD4+ cells are what the HIV virus targets—therefore, having an STI makes you more susceptible to HIV.
What’s more is that people with both STIs and HIV are more likely to give HIV to their partners. People with both STIs and HIV have higher concentrations of HIV in their genital fluids, making them more likely to infect others.
Not all HIV infections are passed through sexual contact—all it takes is blood-to-blood contact. Sharing needles, for instance, puts you at high risk for contracting HIV. When people with HIV use intravenous drugs and inject with the drug into their body, they break the skin barrier and introduce infected blood into the needle. When you share this needle, the infected blood can get into your system and give you HIV.
While people of any age can get HIV through drug use and unprotected sex, some age groups have higher incidences of HIV. If you are younger, you may be more likely to get HIV. Individuals between the ages of 13 and 29 made up 39 percent of new HIV cases in 2009, with people ages 20 to 24 having the highest rates of infection. Young bisexual and gay men were also more affected by HIV than older bisexual and gay men. Being young doesn’t necessarily increase your risk, but it does mean that if you have sex with people your age, you may be more likely to get the infection.
If you think you have been infected with HIV, you should get tested immediately. While there is no cure, testing and treatment can greatly reduce the chances that you spread the infection to others. Treatment and early testing can also help you live a longer, healthier life. Knowing the risk factors for contracting HIV can also help you make better decisions so you can avoid an infection.