What causes HIV/AIDS?
HIV is a retrovirus that infects the vital organs of the human immune system. The disease progresses in the absence of antiretroviral therapy. The rate of disease progression varies widely between individuals and depends on many factors (age of the patient, body's ability to defend against HIV, access to health care, existence of coexisting infections, the infected person's genetic inheritance, resistance to certain strains of HIV).
HIV can be transmitted through:
Sexual transmission. It can happen when there is contact with infected sexual secretions (rectal, genital or oral mucous membranes). This can happen while having unprotected sex, including vaginal, oral and anal sex or sharing sex toys with someone infected with HIV.
Perinatal transmission. The mother can pass the infection on to her child during childbirth, pregnancy, and also through breastfeeding.
Blood transmission. The risk of transmitting HIV through blood transfusion is nowadays extremely low in developed countries, thanks to meticulous screening and precautions. Among drug users, sharing and reusing syringes contaminated with HIV-infected blood is extremely hazardous.
Thanks to strict protection procedures the risk of accidental infection for healthcare workers is low.
Individuals who give and receive tattoos and piercings are also at risk and should be very careful.