What Are My Chances of Getting HIV?

Current Statistics According the CDC

Man unwrapping condom
Man unwrapping condom. Getty Images/Science Photo Library - IAN HOOTON/Brand X Pictures

While there are no fixed answers when addressing a individual's risk of getting HIV, there are activities and behaviors that certainly increase one's likelihood of infection. Chief among these are condom-less (a.k.a. unprotected) sex and sharing needles during injecting drug use.

Moreover, the chance of getting infected increases when a person has multiple risk factors, including multiple sex partners; alcohol or drug use; or the presence of a sexually transmitted infection.

From a purely statistical standpoint, the Centers for Disease Control and Prevention (CDC) has outlined the probability of acquiring HIV by various exposure types. These are based on the HIV incidence in the U.S., a measure which determines how often an infection occurs within a specific population of individuals (e.g., injecting drug users) during a specific period of time.

It's important, however, not to confuse an incidence rate with the risk of infection. For example, a one percent incidence does not mean a one of a 100 chance of getting HIV. The figure should simply be used as a means of relative comparison in understand which types of activities are riskier than others.

Learn more about the per-incidence risk of HIV by exposure type.

Sexual Exposure

According to the CDC, the chance of getting HIV from having sex with a person infected with HIV depends on the type of sex activity, as follows:

  • Receptive anal sex: Risk is 138 per 10,000 exposures or 1.38 percent
  • Insertive anal sex: Risk is 11 per 10,000 exposures or 0.11 percent
  • Receptive vaginal sex: Risk is 8 per 10,000 exposures or 0.08 percent
  • Insertive vaginal sex: Risk is 4 per 10,000 exposures or 0.04 percent
  • Oral sex: Risk is "low" to "negligible"

    It's important to note that there are a number of variables that influence a person's chance of getting HIV from a sexual encounter. For instance, the use of both antiretroviral therapy and condoms decreases a person's risk of getting HIV after a sexual exposure by 99.2 percent. 

    In addition, pre-exposure prophylaxis (PrEP), may decrease a person's risk of getting HIV by more than 90% in some population groups. 

    On the other hand, high levels of HIV in a person's bloodstream (as measured by the HIV viral load) may increase the likelihood his or her partner will get infected. Similarly, having co-existing sexually transmitted infections can greatly increase a person's chance of both transmitting and acquiring HIV

    Injecting Drug Use

    The sharing of HIV-contaminated needles or other drug equipment can spread HIV to a non-infected person. According to the CDC, the risk of transmitting HIV by sharing needles is 63 per 10,000 exposures, or 0.63 percent.

    Needle Stick Injury

    The same data suggests that the risk of getting HIV from a needle stick injury with the confirmed presence of HIV-infected blood is 0.23 percent.

    Blood Transfusion

    While the risk of HIV from a tainted blood transfusion carries the highest risk of getting HIV—roughly 92.5—the actual risk is now almost negligible today due to advanced blood screening techniques.

    Mother-to-Child Transmission

    Mother-to-child transmission during pregnancy, delivery, or breastfeeding is the most common way that children get HIV. As such, it is recommended that women with HIV should not breastfeed (with exceptions made in poor, economically developing countries where the benefits of human milk and nutrition outweigh the risk of infection).

    The good news is that mothers with HIV who take antiretroviral drugs during pregnancy can decrease the risk of transmission to less than 1 percent if the virus is suppressed to so-called "undetectable" levels..

    Other Exposure Types

    Exposure to HIV-infected body fluids, either through biting, spitting, kissing, sharing utensils, or sharing grooming items is considered an unlikely source of infection, with no documented case of infection on record. 

    Final Thought

    Numbers and percentages are ultimately just guidelines. Infection can and sometimes do occur after only one unprotected sexual encounter. The only real way to know if you've been infected is to get tested. In this way, you can begin treatment immediately and better ensure that you have a long, healthy life.

    Sources

    Centers for Disease Control and Prevention (CDC). (2014). "HIV Transmission Risk." Atlanta, Georgia; 2014; accessed September 29, 2015. 

    American Academy of Pediatrics. "Policy Statement: Breastfeeding and Human Milk.."  Pediatrics. Mar 2012; 129(3):e827-41. 

    CDC. "HIV Among Pregnant Women, Infants, and Children." 2015; accessed September 29, 2015. 

    Continue Reading