San Antonio Mayor Ron Nirenberg declared a public health emergency Monday after the federal government released a woman from quarantine who tested positive for COVID-19, San Antonio officials confirmed to CNBC.

The woman was among the 91 Americans evacuated from Wuhan and placed in federal, 14-day quarantine at Joint Base San Antonio-Lackland. The woman tested negative twice for the new coronavirus and was released Saturday under guidance from the Centers for Disease Control and Prevention, Nirenberg said Monday.

Representatives from San Antonio declined to comment on the nature of the emergency declaration or how long it will last.

"Unfortunately after the person's release, the CDC received the results of another test that showed a weakly positive confirmation of the virus that causes COVID-19," Nirenberg said at a news briefing earlier Monday. "As mayor of this city, I find it totally unacceptable that CDC would release a patient prior to receiving all test results and potentially expose the public to this harm."

The woman was released from quarantine on Saturday and arrived at the Holiday Inn Express Airport before 3 p.m., according to a press release from San Antonio Metro Health. The woman also visited North Star Mall, where she browsed stores, including Dillard's, Talbot's and Swarovski and ate at the food court, according to the press release.

The woman was transported to Texas Center for Infectious Disease at 2 a.m., according to the spokeswoman. Local officials are tracking 16 people from the mall and three at the hotel who they believe came into contact with the woman, said Dr. Anita Kurian, assistant director of communicable diseases at the San Antonio Metropolitan Health District.

The city health department has recommended deep cleanings "with disinfectants" to both the hotel and mall, according to the spokeswoman.