The blood of a person with AIDS contains a large amount of HIV. If its fresh blood is drunk directly by another person, HIV will come in contact with the mucous membrane of the digestive tract as well as the oral mucous membrane of the other person and may cause infection. However, if the blood of an AIDS patient is dripped into water, it will be diluted very many times, because HIV is not a suitable living environment in water, so it will quickly lose the relevant infectious activity, and if left for a long time, this route is unlikely to cause infection. However, if the mixed blood is very fresh, and the concentration is relatively large, the amount of mixed water is relatively small, this situation has the possibility of causing infection.