The U.S.’s first deaths from the new coronavirus came weeks earlier than was previously known, suggesting the virus may have long been spreading outside of health officials’ attempts to contain it earlier this year.
Two residents of Santa Clara County, California, who died at home on Feb. 6 and Feb. 17 were infected with the virus, according to a statement Tuesday by the county’s public health department.
The first death is 20 days earlier than what was previously thought to be the first U.S. fatality, and about three weeks before health officials identified the first Covid-19 infection without a known tie to other cases. The deaths were also weeks before cities and states began implementing widespread social-distancing measures.
At the time of the first of the newly identified deaths, the U.S. Centers for Disease Control and Prevention had identified only 11 cases of the virus. All were either travelers from abroad or had connections to known U.S. cases.
Previously, the first report of a U.S. death from Covid-19 had come on Feb. 29 in Washington state. Days afterward, two earlier deaths in Washington state were attributed to the viral illness, both occurring on Feb. 26.
U.S. attempts to track the virus at the time were hampered by shortages of tests and highly limited criteria for who could be tested. In early February, the U.S. was still relying on the CDC for all testing of potential cases. Tests sent out by the agency to state and local health labs later that month turned out to be unusable, and widespread testing only became available weeks later.
“Testing criteria set by the CDC at the time restricted testing to only individuals with a known travel history and who sought medical care for specific symptoms,” Santa Clara County’s public health department said in the statement. “We anticipate additional deaths from Covid-19 will be identified.”
Researchers in California have been trying to understand how far the disease has spread in the state. There are only about 36,000 confirmed cases there, compared with more than 258,000 in New York. One study, which has attracted criticism of its methods and hasn’t been published in an academic journal, estimated that 2.5% to 4.2% of people in Santa Clara County may have already been infected. Similar research is being conducted around the country.
President Donald Trump’s administration has been under fire for its early response to the virus after the World Health Organization declared an international health emergency at the end of January. Trump has said he responded effectively by limiting travel from China.
A third person in Santa Clara county died of Covid-19 on March 6, three days before the county’s first death was originally thought to have occurred, officials said. All three people died at home.