HIV/AIDS

Transmission and Progression

HIV is transmitted by HIV-containing bodily fluids of an infected person entering the bloodstream of another person. It is commonly transmitted through sexual contact, blood-transmitting situations such as intravenous drug use, and from mother to child. The means of transmission can be through blood, semen, vaginal fluid, breast milk, and preseminal fluid. Mother-to-child transmission usually happens in the last weeks of the pregnancy and at childbirth. The treatment developed to stop this transmission reduces the chances of this infection. In the absence of treatment, the rate of transmission from mother to child is 25%. The risk of infection is a function of the viral load of the mother at the time of pregnancy and delivery. Therefore, the availability of treatment to the mother to control her viral load is also important for the child. The availability of treatment is central, and the availability of drugs and associated conditions in developing countries present serious challenges in this area.

Sexual transmission of HIV is the most common route. Unprotected sex increases the likelihood of infection between infected and uninfected person. Unprotected sex with multiple partners also increases the possibility of infection and its spread. Another important transmission route is through blood products used by hemophiliacs and others, for example, those receiving blood transfusions. Sharing and reusing syringes that might have been contaminated by HIV is another important transmission route. An example here is the Chinese case where syringes were used multiple times for blood donations, which increased HIV infections in the country. This mode of transmission is particularly important and is often the main mode of transmission where intravenous drug use is prevalent, such as in eastern Europe and Russia.

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