A resident of Berkeley who recently returned from travel abroad has tested posted for COVID-19, the city's health officer said Tuesday.

The resident, who is the East Bay city's first confirmed case of the novel coronavirus, returned to Berkeley on Feb. 23 from one of a growing number of countries with a COVID-19 outbreak, city officials said.

Concerned about being exposed through travel, the resident has "largely stayed at home in a voluntary self-imposed quarantine," said Berkeley Health Officer Dr. Lisa Hernandez.

The Berkeley health office is investigating whether the infected person had contact with others. Those who have been "potentially exposed" will be identified, notified and evaluated, officials said. Berkeley City Manager Dee Williams-Ridley on Tuesday proclaimed a local emergency, which allows the city to marshal resources to prepare for additional cases.

The U.S. Centers for Disease Control and Prevention and California Department of Public Health are providing guidance on risk exposure and management for the new case, city officials said. "While the risk of infection remains low, the expanded presence of the virus in our community is a reality we should all prepare for," said Hernandez said.

Like other jurisdictions, the city is recommending residents wash their hands often with soap and water; stay home when sick; don't touch faces with unwashed hands; and cover coughs with a tissue or your elbow.

The city's web page on COVID-19 is at cityofberkeley.info/coronavirus/ .

A one-hour Twitter town hall with Dr. Hernandez will be held on Friday at noon. Questions can be tweeted to @CityofBerkeley using the hashtag #BerkCOVID19, or use an online form to submit anonymously.