When kissing, if it is a light kiss or a courtesy kiss, there is no transmission of AIDS and the chance of transmission is 0%. Situations that lead to HIV transmission are only seen in deep kisses, or when a person with AIDS has visible bleeding gums, when there is a possible probability of HIV infection, but there are no specific estimates or statistics for the associated probability. It is possible to refer to the probability of infection by occupational exposure with the blood of the AIDS patient to the health care worker, and the probability of infection is about 0.09% if the mucous membrane is touched during the occupational exposure. This probability can be referenced if the person with AIDS has bleeding gums and the amount is relatively large. If another person has a visible ulcer in the mouth and comes into contact with the blood of a person with AIDS, the probability can be similar to that of contact with broken skin during occupational exposure, which is about 0.3%.