The spread of the coronavirus has raised the question of whether humans are the only ones affected by an illness that has now spread to at least 40 countries.

Will it spread to cats and dogs?

The World Health Organization and the Centers for Disease Control and Prevention have both noted that at present there is no evidence that pets like dogs and cats can be infected by the COVID-19 virus.

"However, it is always a good idea to wash your hands with soap and water after contact with pets,'' WHO noted on its website. "This protects you against various common bacteria such as E. coli and salmonella that can pass between pets and humans."

There have been no reports of any pets testing positive in the U.S. The first report of a pet testing positive for coronavirus came from Hong Kong on Friday.

A spokesman for Hong Kong's Agriculture, Fisheries and Conservation Department said that a pet dog had been tested "weak positive" for the COVID-19 virus, but also noted that AFCD "does not have evidence that pet animals can be infected with coronavirus or be a source of infection to people."

The dog is currently under quarantine at an animal facility in Hong Kong and is being tested to see if it actually has the virus or whether it's a result of "environmental contamination of the dog's mouth and nose," according to the report.

Jonathan Runstadler, a professor of infectious disease and global health at Tufts University's Cummings School of Veterinary Medicine, told TODAY in an email that "there is no good evidence that I have heard that this is the case for the coronavirus responsible for COVID-19 and this positive (Hong Kong) report may equally be due to environmental contamination of the samples taken from the dog."

Runstadler also noted that coronaviruses are common pathogens across mammalian hosts, including pets, but they are generally not threats to humans and vice versa.

"Some uncertainty exists with any novel emerging virus for several reasons, among which are 1) that the mechanisms of infection and transmission are not fully known for this virus and could have components that are shared across mammalian hosts such as human and dog, 2) the origin of human infection and transmission could involve the pet animal or a close relative, making it more likely to be a competent host or 3) there may be some low level of spillover possible due to the ability of a novel virus to adapt under high levels of exposure."

Runstadler also gave some basic tips for any pet owner to follow to prevent the spread of illness.

"Caution is always a good policy and people should wash hands after handling pets in close contact with infected people, maintain good hygiene, and monitor the health status of pets in close contact,'' he said.