According to the latest report, the "patient zero" of covid-19 in the United States can be traced back to the middle of December, mainly introduced from Europe and America. The CDC says there is evidence that early COVID-19 transmission in the United States between late January and early February is due to the low incidence rate of COVID-19, which can not detect COVID-19 similar diseases through emergency department syndrome monitoring.
So far, the Centers for Disease Control and prevention in the United States has tested nearly 11000 samples taken from patients suspected of influenza. The first positive covid-19 was detected on February 25. This was two days before California authorities reported the presence of new crown transmission in the state community.
Once an infectious disease reaches
The CDC said it did not turn a blind eye to the virus, despite widespread criticism of the agency's overall response and early measures. "We have never neglected the surveillance of the new coronavirus," CDC said. The reality is that the CDC's surveillance system for respiratory diseases such as influenza has made us pay attention to the virus before the outbreak. "
The Los Angeles Times quoted Santa Clara County Health Director Sarah Cody on April 23 as saying that because the flu season, coupled with limited testing, the new coronavirus understanding is still in its early stages, so the deceased was mistaken for dying of the flu.
On March 11, CDC Director Robert Redfield admitted in the U.S. House of Representatives hearing about the new crown outbreak, the United States has a new crown death cases are mistaken for influenza deaths.
Cody said the newly confirmed deaths, like the "tip of the iceberg ", represented a large number of new crown cases that were not detected in time, partly reflecting the severity of community transmission. Because it wasn't confirmed by virus testing ," it's definitely missing a lot of new cases ".
The United States imposed travel restrictions on China on February 2, Iran on March 2, Continental European countries on March 13, and Britain and Ireland on March 16 to prevent international imports.
Despite these measures, the first new crown confirmed case in New York state occurred in New York City on February 29. In the first weeks of March, as screening capacity expanded, the number of new crown cases in New York increased rapidly. As of May 2, there were 312977 new crown confirmed cases in New York State, of which 172354 (55%) were in New York City. New York City has become one of the major centers of sars-cov-2 infection in the United States, with more than 13300 deaths in its metropolitan areas.