Human Immunodeficiency Virus (HIV) is a virus that attacks the body’s immune system, specifically the CD4 (T) cells, which help the body fight off infections. If left untreated, HIV can lead to Acquired Immunodeficiency Syndrome (AIDS), a condition in which the immune system becomes severely damaged. Understanding how HIV is transmitted and how it is not transmitted is essential for preventing its spread and reducing stigma surrounding the virus.
HIV can be passed from one person to another through the exchange of certain body fluids from someone who is living with the virus. Transmission can occur when these fluids come into contact with certain parts of the body, such as the eyes, mouth, or reproductive areas, or when they enter the bloodstream through an open cut or through shared needles.
The most common modes of transmission include:
- Unprotected sexual contact: Having high risk intercourse without effective HIV prevention measures is the most common way HIV is transmitted worldwide.
- Sharing needles or syringes: People who inject drugs and share needles, syringes, or other injection equipment are at high risk. The virus can survive in a syringe for several days, making this a particularly dangerous route of transmission.
- Mother-to-child transmission: An HIV-positive mother can pass the virus to her child during pregnancy, childbirth, or breastfeeding. However, with proper medical care and antiretroviral therapy (ART), the risk can be reduced to less than 1%.
- Blood transfusions or organ transplants: In countries where blood is not thoroughly screened, there is still a small risk of HIV transmission through contaminated blood or tissue. However, in countries like the United States, where blood donations are routinely tested, this risk is extremely rare.
HIV cannot be transmitted through casual contact. It does not spread through air, water, sweat, saliva, tears, or insect bites. Activities such as hugging, kissing, sharing utensils, using the same toilet, or shaking hands are completely safe. Misunderstandings about these everyday interactions have fueled unnecessary fear and discrimination against people living with HIV.
There are several highly effective ways to prevent HIV transmission. Consistent and correct use of condoms during sex significantly reduces the risk. Pre-exposure prophylaxis (PrEP) is a daily medication that can lower the chance of acquiring HIV by up to 99% when taken correctly. For people living with HIV, taking antiretroviral therapy (ART) consistently can reduce the viral load in their blood to undetectable levels—meaning they cannot transmit the virus sexually (a concept known as U=U, or Undetectable = Untransmittable).
Avoiding the sharing of needles and ensuring that all blood products are screened also play vital roles in prevention. Pregnant individuals living with HIV should seek medical care early to prevent mother-to-child transmission.
HIV is a preventable and manageable condition. Through education, testing, safe practices, and access to treatment, the world has made significant progress in controlling the spread of the disease. Understanding how HIV is transmitted and how it is not transmitted empowers individuals to protect themselves and others, while also helping to eliminate the stigma that too often surrounds this virus.
As Program Manager of HARP, Kim brings over six years of experience supporting people living with HIV and ensuring they have access to the care and resources they need. Her work focuses on reducing stigma, improving health outcomes, and strengthening community understanding through education and outreach.
