Many coronavirus types infect species of animals that occasionally (or rarely) are able to infect humans. MERS coronavirus is an example where the virus that usually only infected camels became able to infect humans. Wuhan coronavirus is similar as the initially infected people frequented an open-air food market that sold fish and animals, including wild animals. Medical researchers currently do not know the animal species infected, but wild animals are a suspected source. However, the rapid spread of the virus was due to person-to-person contact that has been responsible for the wide outbreak of this infection. Close contact with someone who is infected or with their secretions (for example, cough-generated droplets) or feces is how the virus spreads. Although this virus is contagious, the contagious period of time remains to be determined. Recent findings suggest it may be contagious even in the incubation period when the patient shows no symptoms.