Raccoons are dangerous to humans as, according to the Humane Society of the United States, they are one of the primary carriers of rabies. This disease can be fatal in humans.
In addition to rabies, raccoons also carry several other diseases and parasites that are dangerous to humans. Exposure to raccoon feces can lead to roundworm infections, and contact with raccoon urine can lead to leptospirosis. The Human Society reports that although it is rare for a healthy raccoon to attack a human, aggressive raccoons are often infected with rabies, canine distemper or parvovirus. If any raccoon is showing signs of aggression, contact the local animal control services for assistance.