Officials say two people in northern California died from the virus in early February before the first reported death in the US

The coronavirus was killing Americans in the US weeks before health officials, doctors or the government realized, it emerged early on Wednesday.

Health officials now say two people died from Covid-19 in California in early February before the first reported death from the disease in the United States.

Santa Clara county officials, in northern California, said they now know a 57-year-old woman died in her home on 6 February and and a 69-year-old man died in his home on 17 February. The woman, Patricia Dowd, was a San Jose resident, according to public death records.

The first official recorded death in the nation from the virus was reported on 29 February in Kirkland, in the state of Washington. Before the results from the three deaths, officials believed the first case of community-transmitted coronavirus in Santa Clara county had not occurred before 28 February.

The medical examiner-coroner of Santa Clara county, received confirmation on Tuesday that tissue samples obtained during autopsies and sent to the US Centers for Disease Control and Prevention tested positive for the virus, officials said.

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A third such death – a 70-year-old man – had occurred on 6 March. Santa Clara county is south of San Francisco and includes San Jose.

“What these deaths tell us is that we had community transmission, probably to a significant degree, far earlier than we had known and that indicates that the virus was probably introduced and circulating in our community far earlier than we had known,” said Dr Sara Cody, health director in Santa Clara county.

The first officially confirmed case of coronavirus in the US was on 21 January, in Washington state. The latest news from California indicates to officials that coronavirus was spreading in the community by early to mid-January, much earlier than thought.

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Cody called the three deaths “iceberg tips” – indicators that spread had been much worse than what experts originally thought. She noted that since testing at the time was limited by the federal government’s guidance on who should be tested, health officials were unable to act sooner.

“When we identified our first travel-associated cases in late January, we had a very narrow case definition,” Cody said. “We were only looking among people who had traveled. We were wondering, how do we detect community transmission if we’re not testing people who haven’t traveled? I think this answers the question in that we didn’t detect community transmission.”

None of the three early deaths had significant travel history, Cody said. She suspects that the region’s “robust influenza season” this year may have included some cases of coronavirus.

The announcement came after the California governor, Gavin Newsom, promised a “deep dive” update on Wednesday of the state’s ability to test for the coronavirus and to track and isolate people who have it, one of the six indicators he says is key to lifting a “stay-at-home” order that has slowed the spread of the disease while forcing millions of people to file for unemployment benefits.

“This will go to the obvious questions and queries that all of us are asking: When? … When do you see a little bit of a release in the valve so that we can let out a little of this pressure,” Newsom said.

Newsom said the state was testing an average of 14,500 people a day, up from just 2,000 tests a day at the beginning of April.

Still, in a state of nearly 40 million people, that’s not enough for public health officials to know for sure the reach of the highly contagious virus that is still causing outbreaks across the state in nursing homes and homeless shelters.

Newsom said he wants the state to test at least 25,000 people a day by the end of April.

California has more than 35,600 confirmed coronavirus cases and 1,300 deaths, according to data compiled by Johns Hopkins University.

California has been under a mandatory, statewide stay-at-home order for more than a month.

Last week, Newsom said he will not consider loosening that order until hospitalizations, particularly those in intensive care units, flatten and start to decline for at least two weeks. On Tuesday, Newsom announced intensive care hospitalizations rose 3.8%.

Agencies contributed reporting