The number of confirmed cases of coronavirus continues to grow daily. Readers have asked whether the origin of mail and purchased items could affect them.

The United States has more than 100 confirmed cases of coronavirus, and new infections are being reported daily. On Tuesday, Amazon said it recently had a Seattle-based employee test positive for covid-19, the disease caused by the virus. A spokesperson for Amazon told The Washington Post that the ill employee is in quarantine. (Amazon chief executive Jeff Bezos owns The Post.)

Many of the retailer’s merchants and suppliers are based in China, where one city, Wuhan, became known as ground zero for the virus. That connection has led many readers to question whether they should be fearful of parcels coming from affected areas in China or elsewhere.

The simple scientific answer, according to epidemiologists: No.

“There’s no evidence that there’s been spread from infected mail or packages,” said Michael Merson, a dean’s special adviser at the New York University School of Global Public Health.

Merson, who is also director of the SingHealth Duke-National University of Singapore Global Health Institute, said lab studies have shown the virus can survive up to eight or nine days, but he stressed that factors such as temperature and humidity play a factor in such research.

“If I put anything on a surface, that doesn’t tell us about the real world,” he said, noting the virus is mostly spread through droplet infections. “We just don’t have any evidence that this has ever been a problem.”

The virus does not last long on objects such as letters or packages, according to the World Health Organization.

If people are ordering internationally, contracting the virus is even less of a concern, said Xi Chen, assistant professor of public and global health and economics at the Yale School of Public Health.

Chen said viruses similar to the coronavirus, such as SARS and MERS, like low temperatures and low humidity, which aren’t consistent in transit.

Proper hand-washing and touching your face less are the best protections against the coronavirus, said Amar Adalja, senior scholar at the Johns Hopkins Bloomberg School of Public Health.

“It’s important to be alert, but it’s not a time to panic,” he said. “The vast majority of cases are going to be mild.”

Correction: A previous version of this report incorrectly identified MRSA as a virus related to the new coronavirus. The correct virus is MERS. The story has been updated.