Public toilets do not cause the spread of HIV because HIV is relatively weak against the outside environment. If someone’s bodily fluids get on the toilet, HIV does not remain active for a long time and will be inactivated under such circumstances, so even if other people get it on their own skin, it is unlikely to cause transmission. If other people stain their own vulvar mucosa with secretions while sitting on the toilet, the possibility of infection is also extremely small. Therefore, it is unlikely that public toilets can cause HIV transmission, not that there is no such possibility in theory, but the corresponding chance of transmission is extremely small in terms of probability, so small that it is close to none. Although it is necessary to pay attention to hygiene when using a public toilet, there is no need to worry about the spread of HIV.