The ways of HIV infection are: 1. Sexual contact transmission: including sexual contact between same sex and opposite sex. There is a large amount of virus in the semen or vaginal secretions of HIV-infected people. During sexual activities (including vaginal intercourse, anal intercourse and oral intercourse), due to the friction of the intercourse area, it is easy to cause a slight breakage of the genital mucosa, and then the virus will take advantage of the situation and enter the blood of uninfected people. It is worth mentioning that the risk of anal intercourse is greater than that of vaginal intercourse because the intestinal wall of the rectum is more easily broken than the vaginal wall.
2. Blood transmission: (1) Importation of HIV-contaminated blood or blood products; (2) Sharing of HIV-contaminated, unsterilized needles and syringes among IV drug addicts; (3) Sharing of other medical devices or household utensils (e.g., sharing toothbrushes and razors with an infected person) may also be transmitted via the breach, but is rare. (4) Incomplete or non-sterilized syringes and needles; poorly sterilized or non-sterilized stomatological instruments, midwifery instruments, surgical instruments, needles for needling treatment; non-sterilized knives and needles for hairdressing, cosmetology (e.g. eyebrow tattooing, ear piercing), tattooing, etc., and non-sterilized pedicure knives in bathrooms; transfusion of blood or blood products from blood donors who have not been tested for HIV antibodies, and bone marrow transfusion and organ transfer in similar cases. When rescuing a bleeding casualty, the rescuer’s own broken skin comes in contact with the casualty’s blood.
3. Mother-to-child transmission: Also known as perinatal transmission, this is when an HIV-infected mother transmits HIV to her fetus or infant before delivery, during labor and delivery, and shortly after delivery. It can be transmitted through the placenta, or through the birth canal during delivery, or through breastfeeding.
People at high risk are: homosexuals, sexually promiscuous people and people with multiple sexual partners, intravenous drug addicts, people who receive blood transfusions and blood products, hemophiliacs, and children whose parents are AIDS patients. Patients with STDs, especially those with genital ulcers (e.g. syphilis, soft chancre, genital herpes) should also be classified as high-risk groups for AIDS.