These maps are tracking the spread and risk of the Wuhan coronavirus in real time

Researchers from Northeastern University and elsewhere have launched online maps that track the spread and risk of the new coronavirus outbreak.

The pneumonia-like illness was first identified in late December in Wuhan, the capital city of central China’s Hubei province. China has confirmed more than 4,500 cases of the virus, with more than 100 deaths, as of Tuesday, January 28.

Chinese authorities on Thursday took the extraordinary step of locking down Wuhan and the nearby cities of Huanggang and Ezhou — which are collectively home to more than 18 million people — to prevent further spread of the virus.

Cases have also cropped up in other Asian countries and this week one case was diagnosed in the United States.

The US case was a man in the state of Washington who had traveled to Wuhan.

To track the virus’s spread, researchers from the Center for Systems Science and Engineering at Johns Hopkins University have created an interactive map that will update daily to show the numbers and locations of confirmed cases and deaths.

And researchers from Northeastern University, the ISI Foundation, the Fred Hutchinson Cancer Research Center, and the University of Florida have launched a different map that estimates the risk of international spread of the virus, based on daily airline and commuting patterns.

Countries around the world have begun monitoring incoming airline passengers for symptoms of the virus, which can cause fever, coughing, trouble breathing, and pneumonia.

On Wednesday night, nine passengers from Wuhan were screened at Logan International Airport in Boston after arriving there on a Cathay Pacific flight. None were found with symptoms, officials said. It’s unclear if other passengers will have to undergo similar screenings when they land in Boston. Screenings are taking place at five other US airports.

Massachusetts public health officials said Wednesday the risk of the new coronavirus striking in the state right now is small, but they’re working closely with the US Centers for Disease Control and Prevention to monitor the rapidly evolving situation.

Officials advised people to continue to do what they’ve already suggested that people do to stave off the flu virus that goes around this time of year.

“People should continue taking precautions to avoid illness, including urging people with flu-like illnesses to stay home, washing hands, using alcohol-based hand sanitizers, and covering coughs,” DPH spokeswoman Ann Scales said in a statement.

Martin Finucane and Emily Sweeney of the Globe staff contributed to this report. Material from Globe wire services was used in this report.