District of Columbia Mayor Muriel Bowser speaks Saturday at a news conference to announce the first presumptive positive case of the new coronavirus, technically known as COVID-19, in Washington. Credit: Patrick Semansky | AP

WASHINGTON — Several hundred people are being asked to self-quarantine after potential exposure to the first confirmed case of the new coronavirus in Washington, D.C., identified as the rector of a prominent Episcopal church.

District of Columbia Mayor Muriel Bowser said Monday that anyone who entered Christ Church Georgetown on Feb. 24 or between Feb. 28 and March 3 is requested to self-quarantine for two weeks from the date of their entrance to the church.

The new precautions come as the virus continues to roil the normal routine in the nation’s capital. A popular convention city and a springtime destination for hundreds of school trips and thousands of tourists, Washington officials have insisted that the city remains open for business. But tourism leaders admit that they expect virus fears to cut into the visitor numbers — including for the popular Cherry Blossom Festival, which starts on March 20.

Officials on Saturday had announced the district’s first positive test, but identified the victim only as a man in his 50s. A second local positive test involves a man who visited the Washington area from Nigeria, but he was being hospitalized in Maryland.

The Rev. Timothy Cole, the church rector, announced Sunday that he was the person whom city officials had been referring to as “patient 1.” He remains hospitalized in stable condition and the church has canceled all activities until further notice.

Late Monday, the district announced three more confirmed cases, including one man who had attended Christ Church. The church’s Facebook page said its organist/choirmaster was quarantined at home but feeling well “given the circumstances.”

Dr. Anjali Talwalkar of the Washington Health Department said Monday that an exposure risk is defined as coming within six feet of a person with active virus symptoms.

“Several hundred people were potentially impacted,” she said.

A Washington high school linked to the second case was closed Monday, though no new confirmed coronavirus cases have been reported. Three people who stayed at the same house as the Nigerian man who tested positive in Maryland were tested Sunday and all were negative. But one of them works at the School Without Walls High School. Bowser said the school was closed for a deep cleaning and to give time to communicate with staff and parents; she expects the school to re-open Tuesday.

Two charter schools in Washington, D.C., also voluntarily closed Monday but there have been no reported or suspected virus cases linked to either.

Several Republican members of Congress announced they would self-quarantine after coming in contact with an infected person during the recent Conservative Political Action Conference.

Bowser said she was “evaluating” whether to declare a “public health emergency” if the virus continues to spread. As both a mayor and the de-facto governor of a quasi-state, Bowser has more powers than the average city mayor. Formally declaring a health emergency would enable her to impose quarantines and closures and also take steps to prevent price gouging on supplies, she said.

“I don’t believe that’s where we are right now,” Bowser said.

Maryland has reported six confirmed cases. Virginia has reported three.

Associated Press writers Michael Balsamo, Robert Burns in Washington and Randall Chase contributed to this report.