Understanding The Science Behind HIV Transmission

HIV transmission and ways to prevent

Still a disease without a cure, AIDS is an undeniably scary topic to tackle. Because of this, several myths have popped up about what exactly causes HIV and AIDS. It’s important to know what’s true and what’s not so that you can protect yourself and your loved ones from getting infected.

Understanding HIV And AIDS

The Human Immunodeficiency Virus (HIV) harms your immune system by destroying CD4 (T-cell) lymphocytes, which are a type of white blood cells. These cells fight off infections by protecting you from viruses, bacteria, and other germs. So, when T-cells deplete, you’re at serious risk of multiple infections. These infections are called “opportunistic” because they have the opportunity to strike only when the body’s defenses are down. They also raise the risk of some cancers and neurological problems.


There’s no vaccine that can protect you from HIV. And if suitable treatment isn’t given to manage the condition, the HIV infection can worsen and cause irreparable damage.

Acquired Immune Deficiency Syndrome (AIDS) is the last stage of an HIV infection. The severity of your HIV infection is mainly defined by the level of damage that your immune system has endured. This can leave you vulnerable to a host of infections. While AIDS is the late stage of an HIV infection, not everyone who has HIV contracts AIDS.1


Understanding HIV Transmission

For the HIV virus to be transmitted from one person to another:

First, the virus should be present and active in the host’s body.


Body fluids that can contain and transmit HIV include blood and menstrual blood, semen and pre-seminal fluid, vaginal secretions, rectal fluids, and breast milk.

Second, there should be a suitable medium for the virus to spread.


The active HIV virus can only spread if any of these bodily fluids come in contact with a mucous membrane or damaged tissue, or if they’re mixed directly into the bloodstream (say, through a needle or syringe). Mucous membranes are usually found in the opening of the penis, vagina, rectum, and mouth.2 3

How Can HIV Be Transmitted?

Before we get into how you can get HIV, remember that an HIV infection is not something you can always spot in another person. Most people with an HIV infection don’t necessarily “look sick” in terms of their outward appearance. Some don’t undergo the required tests and may not even be aware that they’re infected. Always err on the side of caution.


1. Sexual Behavior

In the US, HIV is mainly spread as a result of risky sexual behavior. You put yourself at high risk when having vaginal or anal sex with an HIV-positive person without using a condom or taking medication to prevent and treat HIV.

Anal sex: For an HIV-negative person, receptive anal sex with an infected partner can be highly risky. Insertive anal sex can also lead to HIV infection. During anal sex, there’s a good chance that the fragile tissue lining your anus will rupture and bleed. This makes it easier for the virus to enter the bloodstream.4


Vaginal sex: When it comes to vaginal sex, either partner stands the same chance of being infected. However, this kind of sexual behavior is less risky than receptive anal sex.

Oral sex: Oral sex can also lead to an infection if an HIV-positive man ejaculates in his partner’s mouth. However, the chances of transmitting or being infected by the HIV virus through oral sex is low.


2. Direct Contact With Blood

HIV is also known to spread through the use of syringes, needles, or any other equipment that’s used to prepare and inject drugs when they’re shared with an HIV-positive person. Depending on temperature and other factors, the HIV virus can live in a needle for up to 42 days.5 Tattooing or body piercing, which breaks the skin, can also be risky if needles are shared.

3. Infections In Healthcare Settings

There have been instances where people have been infected by HIV after receiving a blood transfusion or an organ and tissue transplant from an infected donor. Healthcare workers are also vulnerable to HIV infections as they come into frequent contact with HIV-contaminated needles or other sharp objects.

4. From Mother To Baby

The HIV virus can be transmitted from a mother to her newborn during pregnancy, birth, or breastfeeding.

5. Other Less Common Ways

Eating food that’s been chewed by an HIV-infected person can cause the virus to be transmitted. This happens if infected blood has mixed with the food and has only been seen among infants.

Being bitten by an HIV-infected individual can also lead to an infection, but only if the skin has been broken. This has only been seen in cases where there was serious trauma, damage to tissue, and bleeding.

6. STDs Up Your Risk Of HIV

Another important thing to know is that having an STD can increase your chances of being infected by HIV. The same risky sexual behaviors that put you at risk of having an STD can lead to an HIV infection as well. A sore or break in your skin caused by an STD can also be an easy gateway for the HIV virus to enter your system. There has to be contact between broken skin, wounds, or mucous membranes with contaminated or infected body fluids for HIV transmission.6

Body Fluids That Don’t Transmit HIV

Not all bodily fluids transmit HIV. You don’t have to worry about the following:

  • Sweat
  • Tears
  • Saliva
  • Urine
  • Feces7

Myths Surrounding HIV Transmission: What You Shouldn’t Believe

There are plenty of myths about how you can get an HIV infection. Here, we break down the most common ones.

You cannot get or transmit HIV through:

  • Air or water
  • Hugging, social kissing, or shaking hands (casual social contact)
  • Masturbation
  • Fantasizing
  • Dry or closed mouth kissing
  • Phone sex
  • Cyber sex
  • Massage
  • Insect bites
  • Pets
  • Sex toys you don’t share
  • Breathing the same air
  • Food cooked by an HIV-infected person
  • Living in the same house with someone who has HIV
  • Sharing showers or toilets with someone who has HIV8

Proven Ways To Prevent An HIV Infection

The HIV virus infects you mainly by getting inside your blood cells. To avoid an infection, you must prevent the virus from entering your body through the mouth, anus, vagina, tip of the penis, wounds, or breaks in your skin.9

  • As risky sexual behavior is one of the primary means of HIV transmission, simply using a condom – whether you engage in vaginal, anal, or oral sex – is highly effective.
  • If you have a serious drug habit, avoid sharing needles, syringes, or other equipment with anybody else.
  • If you need a blood transfusion or an organ or tissue transplant, ask your healthcare professional to test the products for HIV.
  • If you’re part of the healthcare sector yourself, wearing protective gear like gloves and goggles, maintaining good personal hygiene after contact with blood or other bodily fluids, and safely disposing of sharp equipment is beneficial for you and the people around you.10

HIV Prevention For Expectant Mothers And Newborns

Newborn babies are always at risk of being infected with HIV if their mothers are infected first. The infection can happen when the mother is pregnant, during birth, or through breastfeeding. It is absolutely imperative that pregnant women be tested for HIV. With proper treatment for HIV at the right time, the chances of the virus spreading from the mother to the baby reduces. Even if an infected woman does give birth, special medication can be given to the newborn to try and prevent the HIV infection.11

There is currently no known vaccine for HIV and no cure for AIDS. Being educated and aware about HIV transmission can help you take the right steps to easily prevent it.