Head of CDC defends failure to detect early coronavirus epidemic in US

Redfield was one of the three CDC officials who spoke with reporters on Friday. Comprehensive analysis According to the agency that discovered the coronavirus, it began spreading to the United States as early as late January, evading detection by public health surveillance systems, which helped monitor early signs of new infections.

The reporter who received the report demanded that he speak with an expert. that is First such CDC briefing In almost 3 months.

The report examined public health survey data, confirmed cases of covid-19, and confirmed infection with different gene strains of the virus. The results explain the two-stage virus attack by the coronavirus introduced by travelers from China that began on the West Coast in January and are consistent with other scientific studies that followed in February. Travelers from Europe Brought the virus to the east coast. Most of the viruses that are widespread in the United States come from infections from Europe.

According to Redfield, the findings subvert speculation that the virus had spread months ago.

“The opinion spread that there was a significant sowing of the country in November, December and January,” Redfield said. “And the data clearly shows that the virus was introduced early in northwestern and northern California between the second week of January and the second week of February. Evidence.

Jay Butler, deputy director of infectious diseases at CDC, said the findings also show that the infections are limited and not as widespread as some experts suggested.

Response to Failed CDC rollout In a test kit that, according to experts, was said to have allowed the virus to settle and spread quickly, Redfield said the diagnostic tests had little change at that time. When US cases were first detected in January and February, health officials identified approximately 800 high-risk individuals who were in contact with infected patients. He said only two of them were positive.

Still, it doesn’t mean that the authorities simply have to wait for the needles to “replicate until they reach the haystack,” said William Hanage, an epidemiologist at Harvard University. Chang Public Health School.

“A series of Missed opportunity “Here,” he said. “Surveillance at the time was absolutely inadequate in catching such pandemic viruses whenever they were introduced.”

Michael Woloughby, an evolutionary biologist at the University of Arizona, New paper Analyzing the initial spread of the virus in the United States, his study said that the spread of communities on the West Coast probably did not begin before the first week of February. It’s only a few weeks later First Washington patient Arriving by plane from Wuhan, China, but up to Urobay, it was enough time to take action to limit the outbreak.

“It would be ridiculous not to realize that there were some failures in the way the test was deployed,” Wrobey said.

He said the details of virus introduction and spread are important for understanding exactly what happened and what can be done to prevent future outbreaks.

“ When the plane crashed, the way to investigate these things down to all the pieces of rubble was very impressive, finding out what went wrong without trying to brush anything under the carpet. He said.

The genetic data that was part of the report’s evidence showed that the virus was more likely to penetrate the country and began to spread before extensive testing and contact-tracking rollouts, and before the Trump administration almost banned it. Stressing Travel from China, Starting February 2, March 13 in Europe.

Paper published on Friday Journal science It turned out that New York City was inoculated with the virus at least once, perhaps at the end of January, at least eight times in separate events. The initial referral was from people with a known travel history and was not associated with later community clusters, the report says.

However, the outbreak is still occurring, and virus samples can be traced back to Europe, “probably reflecting a local infection from an undetected introduction,” the paper said. Only one of the virus sequences introduced in mid-February Spread in New York City, Anaylvia Gonzalez-Lyche, virologist at Ikhan School of Medicine, is the first author of the paper. There is no laboratory evidence that this sequence was more contagious or dangerous than others, she said. “It looks like we were in luck,” she said.

The test did not expand until mid-March. Experts said that if more tests were available in January and February, researchers would be more likely to determine the magnitude and speed of the outbreak.

“It was very disappointing that no extensive oversight had taken place early,” said Jennifer Nuzzo, an epidemiologist and senior researcher at the Johns Hopkins Health Center. I am.

“We’ve isolated people and lost months of time that would have been able to prevent the case from accelerating as we did,” she said.

Without better testing, the researchers sought to reconstruct what happened. They examined epidemiologic data in April and found that the virus circulated in the community before it identified a February 26 patient in California, which was previously thought to be the first confirmed case of community expansion. I understand whether or not.

Researchers concluded that in mid-January it was likely that covid-19 was transmitted to the community in the United States, with the first such case becoming sick in late January on February 6 in California. Confirmed in a woman who died in.

Studies found low levels of local transmission in late January in California and Washington after importing cases from China. However, the levels were too low for anyone to notice, and the emergency department did not see a spike in patients with symptoms consistent with covid-19.

This is also in line with what is known about community infections. It takes weeks to reach the critical mass that triggers the alarm. A retrospective analysis of over 11,000 conserved respiratory samples collected from January 1 showed no positive test for covid-19 until February 21 in Washington. The virus was already prevalent, but below epidemiological radar.

The report concludes that “sustainable community transmission has begun” before the virus was detected in two cases in California and Washington at the end of February. They were the first American patients with no history of traveling to China.

The researchers said the spread probably resulted from “late January or early February imports of a strain of virus from China, followed by multiple imports from Europe.”

The CDC report raises an interesting speculation that the first known case in the United States may have begun to spread in a way stealth that was unidentifiable at the time. The authors of the study say investigators performed rigorous contact follow-up on the first patient. However, they did not examine all patients’ contacts before symptoms appeared. At that time, the standard protocol for contact tracking had not reached the potential presymptomatic spread, the CDC said.

Also, as another issue, the contact trace did not identify people who were in contact with the secondary contact, the ring of the first contact. Thus, a patient can infect people who have never developed symptoms with the virus, and then infect one who has become one of the infected in the area.