2.2. Transmission routes
The virus transmission paths are well researched. Gone are the days when it was thought that HIV infection is a disease that affects only drug users, commercial sex workers and men who have sex with men (MSM). Anyone can get infected with HIV, regardless of social status, wealth, sex, age, and sexual orientation. The virus in a concentration sufficient to be transmitted to another person is found in blood, semen, vaginal secretory glands and human breast milk. Other fluids of the human body, such as saliva, sweat and tears are not dangerous. The virus can be present in them, but in very small quantities.
HIV is not transmitted when an infected person shakes hands or hugs the other person, as intact skin is an insurmountable barrier to the virus. The virus cannot be transmitted through towels, clothes, linens, shared tableware, sneezing, kissing or via mosquito bites. The virus very quickly perishes in an external environment.
There are several ways of HIV transmission:
- The virus can be transmitted through “blood to blood” contact. Such contact can occur as follows:
- use of non-sterile medical instruments such as scalpels or syringes,
- untested blood transfusion,
- use of non-sterile medical instruments (for example, when applying tattoos or cosmetic procedures),
— most often, the infection is transmitted through the sharing of needles, syringes and other paraphernalia associated with injectable drugs.
- HIV is transmitted through unprotected sexual contact. The virus enters the body through the mucous membranes, when there is inflammation or micro-traumas of the skin, genitalia or anus. The virus cannot penetrate through healthy, intact skin.
In the absence of treatment — during any kind of sexual contact— the host sexual partner runs more risk to get HIV than the transmitting partner. Regular sexual contacts with a person who has HIV infection, significantly increase the risk of HIV transmission. Women have a higher probability of infection, as a large amount of sperm gets into the vagina and it has longer contact with a larger mucosal surface.
The risk of infection of the host partner through unprotected anal sex is higher regardless of sexual orientation, as the mucous membrane of the rectum is easily traumatized.
The risk of the host partner to get HIV through unprotected oral sex is minimal, and that of the active partner is practically equal to zero. However, the risk increases if the corners of the mouth has sores and ulcers.
- HIV can be transmitted from mother to a child both in the prenatal period (through defects in the placental barrier), and during childbirth, when the child comes into contact with the mother’s blood (vertical transmission) or during breastfeeding. However, in the case of prevention and appropriate treatment of the mother, the risk of transmission of the virus to a child reduces to zero. Currently, in some countries (Thailand, Armenia, Cuba, etc.) of the world, there are no newborns with HIV infection.
HIV-positive people who are undergoing effective therapy and, therefore, have a non-identifiable viral load, are not dangerous and the risk of transmitting HIV to another person is reduced to zero.