The incubation period of AIDS is about 8-9 years on average. AIDS is an extremely dangerous infectious disease caused by the AIDS virus, which can destroy the body’s immune system and then infect various viruses and bacteria, and can lead to malignant tumors and a relatively high death rate. It is believed that AIDS originated in Africa and was brought to the United States by immigrants. AIDS is mainly contracted through blood contact, sexual contact, and vertical transmission from mother to child. Fever, swollen lymph nodes, and uncontrollable diarrhea may occur after the acute infection period. For ordinary household contacts, such as ceremonial kisses and shared meals, HIV is not contracted.