Can HIV Be Spread Through Casual Contact?

Doubts persist even when risk is statistically zero

sneezing and hiv
Unlike the cold or flu, HIV cannot be passed by sneezing. James Gathany/CDC

Despite increased public awareness about HIV, there remains a lot of confusion about how you can get infected and how you cannot.

As much as we'd like to think, for instance, that people understand that you can't get HIV from utensils, there are many who will experience a twinge of anticipation if they learned that, say, the chef of their favorite restaurant had HIV.

HIV has a way of spurring anxieties in even the best of us and, with it, our sense of reason.

Relieving those anxieties often requires us to do more than just lay out the rules. Instead, we need to understand what conditions are required for an infection to take place and why things like hugging, touching, sneezing, or kissing simply do not satisfy those conditions.

4 Conditions Needed to Transmit HIV

As serious an infection as HIV is, the virus itself is not all that robust. Others, like the flu and cold viruses, are far more sturdy and can be passed from one person to next by sneezing.

HIV cannot. Instead, there four conditions that must take place in order for infection to occur:

  1. There must be body fluids in which HIV can thrive. For HIV, this means semen, blood, vaginal fluids, or breast milk. HIV cannot survive for very long in the open air or in parts of the body where is high acid content (such as the stomach or bladder).
  2. There must be a way for the body fluids to enter the body. This happens primarily through sexual contact but can also be spread through shared needles, accidental blood exposure in healthcare settings, or transmission of the virus from mother to child during pregnancy.
  1. The virus must be able to reach vulnerable cells and tissues inside of the body. It is not enough for a body fluid to come into contact with skin. It needs to either enter the bloodstream through a break in the skin or penetrate vulnerable mucosal tissues of the vagina or rectum. Moreover, the likelihood of infection is directly associated with the depth and size of the penetration. A deep cut or wound, for example, provides a more likely route of transmission than a minor scuff or scrape.
  1. There must be sufficient amounts of virus in the body fluid. This is why saliva, sweat, and tears are unlikely sources of infection since the enzymes in these fluids actively break down HIV and its genetic structure.

How HIV Cannot Be Spread

From both a biological and epidemiological evidence, HIV cannot and has never been shown to be passed from one person to the next by the following means:

  • Touching, hugging, kissing or shaking hands
  • Touching an object an HIV-positive person has touched
  • Sharing utensils or cups
  • Eating food prepared by an HIV-positive person
  • Sharing grooming items, even toothbrushes or razors
  • Getting spit on by an HIV-positive person (even in the eyes or mouth)
  • Getting bitten by an HIV-positive person (even if blood is drawn)
  • Touching semen or vaginal fluid
  • Getting blood from an HIV-positive person on you
  • Using public fountains, toilet seats, or showers

To date, there has not been a single documented case of transmission by any of these means.

What to Do If You're Not Sure

HIV hotlines are used to getting calls from people who are afraid they have been infected through casual contact. Perhaps the person was involved in a fight or came into contact with someone who was bleeding. Others may worry about having deep kissed someone who may or may not have HIV.

While the likelihood of infection in these cases would be considered negligible to nil, people will often want a 100 percent guarantee that they're going to be fine; nothing less will suffice. In such case, doctors will usually take the opportunity to perform an HIV test and perform pre- and post-test counseling to better understand what the person knows about HIV and answer any questions he or she might have.

If there is a risk of actual transmission, however small, the doctor may opt to prescribe a 28-day course of HIV medications known as post-exposure prophylaxis (PEP) which may avert infection if treatment is started within 72 hours of the suspected exposure.

In cases where the person's fears seem extreme and unreasonable, counseling may also be needed to address the possibility of AIDS phobia or other possible anxiety disorders.

Sources:

Hughes, A. and Alford, K. "HIV Transmission: Myths about Casual Contact and Fear about Medical Procedures Persist Among Older Adults." J Soc Work Pub Heal. 2017: 32(1): DOI 10.1080/19371918.2016.1188743.

U.S. Preventive Services Task Force. "Screening for HIV: U.S. Preventive Services Task Force Recommendation Statement." Rockville, Maryland; April 2013

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