The US reported at least six deaths from the coronavirus on Monday as officials warned of a “substantial outbreak” in the state of Washington and states of emergency were declared in various parts of the country.

Both patients were being treated at the same health centre in Kirkland, east of Seattle, where six of the state’s 12 cases have now been confirmed and 50 others are being tested for the virus. As the number of nationwide cases approaches 100, sales of face masks have surged among the general population.

Meanwhile, at least one patient was mistakenly released by the CDC and later tested positive for the deadly Wuhan coronavirus, with the mayor of San Antonio describing the development as “unacceptable” in a statement.

Health officials in Washington state meanwhile said on Sunday night that a second person had died from the coronavirus — a man in his 70s from a nursing facility near Seattle where dozens of people were sick and had been tested for the virus.

Researchers said earlier the virus may have been circulating for weeks undetected in Washington state.

Coronavirus: Streets around world left empty Show all 10 1 /10 Coronavirus: Streets around world left empty Coronavirus: Streets around world left empty A man wearing a face mask crosses a road in Wuhan, the epicentre of the novel coronavirus outbreak. Reuters Coronavirus: Streets around world left empty A view of the empty entrance to the UniversitÃ Cattolica (Catholic University) in Milan, northern Italy, on 24 February, 2020. EPA Coronavirus: Streets around world left empty Empty streets in Daegu, South Korea, on 23 February, 2020. EPA Coronavirus: Streets around world left empty Empty streets in Daegu, South Korea, on 23 February 2020. EPA Coronavirus: Streets around world left empty A lone sanitation worker sits near the closed Hankou Railway Station in Wuhan, Hubei province, China, on February 24, 2020. Reuters Coronavirus: Streets around world left empty A view of a deserted street in Codogno, northern Italy, on February 23, 2020. EPA Coronavirus: Streets around world left empty Italian police officers set a road block in Codogno, Northern Italy, on Monday, Feb. 24, 2020. AP Coronavirus: Streets around world left empty A supermarket closed in Codogno, one the northern Italian towns placed under lockdown, on February 23, 2020. EPA Coronavirus: Streets around world left empty A lone cyclist wearing sanitary masks pedals in the center of Codogno, Northern Italy. LaPresse via AP Coronavirus: Streets around world left empty An empty road at the entrance of the small Italian town of Codogno on February 23, 2020. AFP via Getty

In a statement, Public Health—Seattle & King County said the man died Saturday. On Friday, health officials said a man in his 50s died of coronavirus, the first death from the virus in the US.

Both had underlying health conditions, and both were being treated at a hospital in Kirkland, Washington, east of Seattle.

Washington state now has at least 13 confirmed cases.

State and local authorities stepped up testing for the illness as the number of new cases grew nationwide, with new infections announced in California, Florida, Illinois, Rhode Island, New York and Washington state.

Additional reporting by the Associated Press

Loading....