Ways to catch HIV
HIV is transmitted through body fluids. The major ways of HIV transmission are sexual intercourse, unsafe injecting practices, mother-to-child transmission and transfusion of contaminated blood.
Low risk - no risk
Saliva, sweat, tears: Although traces of HIV can be detected in these fluids in a fraction of HIV patients, there is no evidence suggesting that HIV can be transmitted through contact with saliva, sweat or tears.
Insects: Initially many scientists were worried about transmission of HIV through insects (similar to malaria) however studies to date conclude that transmission from insects to human beings is not possible.
Common ways of catching HIV
In comparison to diseases like the flu or measles, HIV is much less infectious. The infectiousness of an infected person's bodily fluids depends on the amount of virus active in them. This varies during the different stage of the disease. A newly HIV infected person, for instance, is far more infectious than a person who became infected years ago.
Sexual intercourse: The most common way of infection is unprotected sexual intercourse with an infected partner. The highest concentration of the virus is located in blood and semen. Bodily fluid containing HIV can enter the partner through the uretha or anus or a scratch/cut. The skin inside the rectum is very sensitive and fragile and so unprotected anal sex holds a very high risk of infection. The main important protection is using condoms.
Mother-to-child transmission: A child can be infected by its mother before or during birth. There is also a chance of infection after birth through breast milk, which also carries the virus. In the developed world, the risk of mother-to-child transmission has been cut from 25% to less than 2%, through use of antiretroviral therapies and formula feeding instead of breast feeding. However, in resource-limited settings, the percentage of children getting infected is considerably higher.
Unsafe injecting practices: All medical equipment must be appropriately sterilized. Intravenous drug abuse carries the risk of HIV infection if a needle or other injecting equipment is shared with an infected person. Drops of infected blood can remain in the needle and infect the next person that uses it.
Blood transfusion:: Before testing and screening and other measures had been put in place, blood transfusion was an easy route for HIV to spread. Today the risk of getting infected with HIV through a blood transfusion is very slim in most developed countries because screening processes are in place to eliminate high risk groups and already infected blood from the supply.
