Acquired Immunodeficiency Syndrome (AIDS) is a chronic condition caused by the Human Immunodeficiency Virus (HIV). HIV is primarily transmitted through sexual contact, making it a sexually transmitted infection (STI). The virus directly damages the body’s immune system, weakening its ability to fight off infections and diseases.
How HIV Spreads
HIV transmission occurs through direct contact with specific bodily fluids from a person living with HIV who has a detectable viral load. These fluids include blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk. For the virus to spread, these fluids must enter the bloodstream of an HIV-negative person through mucous membranes in the rectum, vagina, mouth, or tip of the penis, or through open cuts or sores.
Sexual contact is the most common way HIV is transmitted, particularly through unprotected anal or vaginal sex. Anal sex carries a higher risk of transmission than vaginal sex due to the delicate tissues of the rectum that can easily tear. Sharing needles, syringes, or other drug injection equipment is also a risk because these items can contain infected blood.
Additionally, HIV can be transmitted from a pregnant individual to their child during pregnancy, childbirth, or breastfeeding if the HIV is not treated.
How HIV Does Not Spread
HIV is not spread through casual contact. The virus does not survive long outside the human body on surfaces, nor can it reproduce. Therefore, you cannot get HIV from activities like hugging, shaking hands, or sharing food, dishes, or toilet seats.
HIV is also not transmitted through saliva, tears, sweat, or insect bites, such as those from mosquitoes. The concentration of HIV in saliva is too low to cause transmission through kissing, even open-mouthed kissing, unless open sores are present in the mouth. HIV is not airborne or waterborne, meaning you cannot contract it by being in the same room as someone with HIV, or by swimming in a pool.
Stopping HIV Transmission
Preventing HIV transmission involves several strategies. Consistent and correct use of condoms during sexual activity creates a physical barrier that prevents the exchange of bodily fluids containing the virus. Pre-exposure prophylaxis (PrEP) is a medication taken by HIV-negative individuals to reduce their risk of acquiring HIV, involving daily pills or long-acting injections.
Post-exposure prophylaxis (PEP) involves antiretroviral medications taken after a potential HIV exposure to prevent the virus from establishing itself in the body. This treatment must be started within 72 hours of exposure. For individuals who inject drugs, never sharing needles or syringes is important, and using new, sterile equipment each time lowers risk.
Additionally, pregnant individuals living with HIV can take antiretroviral therapy (ART) during pregnancy and childbirth to significantly reduce the chance of transmitting the virus to their baby, often to less than 1%. This approach, known as treatment as prevention (TasP), also applies to sexual transmission: people living with HIV who take their ART consistently and achieve an undetectable viral load cannot sexually transmit HIV to their partners.
Understanding HIV and AIDS
HIV and AIDS are related but distinct terms. HIV stands for Human Immunodeficiency Virus, which is the virus that attacks and weakens the body’s immune system by destroying CD4 T cells. An HIV infection can last for many years, and with modern treatment, many people with HIV never progress to AIDS.
AIDS, or Acquired Immunodeficiency Syndrome, represents the most advanced stage of HIV infection. A diagnosis of AIDS occurs when the immune system is severely damaged, such as when the CD4 T cell count drops significantly, or when opportunistic infections or certain cancers develop. While there is no cure for HIV, antiretroviral therapy (ART) can manage the virus, allowing individuals to live long and healthy lives and prevent the progression to AIDS.