Virus transmission has been something of immense concern since the emergence of HIV during the early 1980s. A lack of knowledge about the virus and how it is spread is the main reason for the incredible spike of infections during the past three decades.
Infection is primarily transmitted through sexual contact (exchanged bodily fluids such as infected blood, vaginal secretions or semen), as well as through childbirth (from mother-to-child) or breastfeeding (breast milk):
- Sexual contact (unprotected): The virus is easily transmitted through the exchange of bodily fluids during vaginal, oral or anal contact with an infected person. Fluids the virus infects are semen, blood and vaginal secretions. Once these enter the body, infection is spread from one person to another. Sometimes an infection can be transmitted through mouth sores or small tears that can sometimes occur during sexual activity. Only certain bodily fluids carry the virus making contact possible with certain behaviours, including sexual activity. Fluids that place you at risk when engaging in sexual activity with an infected individual include blood, pre-seminal fluid (pre-cum), semen (cum), vaginal and rectal fluids. HIV is not spread through saliva.
- Sharing of needles or syringes: The use of needles, whether for illicit drug use, piercings or tattoos, that are not hygienically maintained can transmit the virus through contaminated blood. Other viral infections, such as hepatitis are also at elevated risk of being transmitted this way. HIV can ‘live’ for up to 40-odd days on an infected / used needle.
- Needles used in medical care: Healthcare workers are frequently at risk for possible infection when handling needles in medical environments. Workers are trained to take special precautions when handling HIV-infected blood (on needles or when infected blood is splashed during medical handling of an infected person). It is rare, but infection transmission can happen this way.
- Blood transfusions and organs: Infection via a blood transfusion occurs less frequently as all blood products are screened for HIV infections before being used for medical purposes. It can happen, in very rare instances, that infected blood transmits the virus to an otherwise negative status individual during a transfusion procedure. Organ and other tissue transplants contaminated with the virus is another rare, but possible means of transmission if not rigorously tested before use.
- Pregnancy, childbirth and breastfeeding: While extremely rare, a woman infected with HIV can pass on the disease to her unborn baby during pregnancy, through childbirth or while breastfeeding (breast milk). If an expectant mother receives treatment during her pregnancy, risk of mother to child transmission is considerably lowered or completely nullified.
Other means of HIV transmission
As not all bodily fluids carry the virus, those that do must come into contact with damaged tissue (broken skin or a tear) or mucous membranes (such as those found in the vagina, penis, mouth and rectum) in order for an infection to spread.
Theoretically, it is possible to spread an infection through oral sex, but in general transmission in this way is highly unlikely. To transmit infection this way, the mouth must come into contact with an infected person’s penis, anus or vagina (through fellatio, rimming or cunnilingus), as well as through ejaculation in the mouth. The risk of infection is increased if the person giving oral sex has mouth sores, cuts or bleeding gums or the person receiving oral sex has genital sores or cuts, and either party is HIV positive with a detectable viral load.
Other ways HIV can be transmitted theoretically, although extremely rare, include:
- Eating foodstuffs that have been pre-chewed by an infected individual. The only known cases reported are those of infants whereby a caregiver whose infected blood has mixed with food in the mouth while chewing before being exposed to an infant.
- A very small number of recorded cases have shown occurrences of infection through extensive tissue damage following being bitten by an infected individual. Transmission through biting is possible with the presence of contaminated blood coming into contact with broken skin.
- Also, theoretically possible, is contamination through deep, open-mouthed kissing. Saliva does not carry the virus so the exchange of this fluid will not transmit an infection from one person to another. If there is a presence of contaminated blood in the mouth of an infected individual (due to bleeding gums or mouth sores) at the time when it comes into contact with the others’ bloodstream, transmission can occur this way.
Ways HIV is not transmitted
The virus itself cannot reproduce itself outside the human body, and thus does not typically ‘live’ for very long. Therefore HIV/AIDS cannot be spread in any of the following ways:
- Through water or air
- Through contact with saliva, sweat or tears (that aren’t mixed with contaminated blood)
- Through the bites of insects, ticks or mosquitoes (that may have bitten infected individuals)
- Through physical touch, such as closed-mouth kissing, hugging or shaking hands with an HIV positive person.
- By sharing cutlery or crockery with an infected person, as well as a toilet that an infected person has used.
- By sharing food or drinks with an infected person (that aren’t mixed with contaminated blood).