As an infectious disease, the spread of AIDS usually requires the fulfillment of three conditions, namely, the source of infection, the means of transmission and the susceptible population.
1. Source of infection. AIDS patients and HIV carriers are the only sources of infection. The virus can be widely present in the infected person’s blood, body fluids, semen, breast milk, vaginal secretions, wound exudate, etc., which is highly contagious; while the infected person’s saliva, tears, sweat, urine, feces, etc. are less contagious without containing blood and inflammatory exudate.
2. Transmission route. The transmission of AIDS is mainly through sexual transmission, blood transmission and mother-to-child transmission.
3. Susceptible people. Human beings are generally susceptible to AIDS, and homosexuals, intravenous drug addicts, multiple sexual partners, and patients who have received blood products many times are high-risk groups.