This article is from the source 'nytimes' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at https://www.nytimes.com/2020/05/15/us/coronavirus-first-case-snohomish-antibodies.html

The article has changed 30 times. There is an RSS feed of changes available.

Version 9 Version 10
When Did the Coronavirus Arrive in the U.S.? Here’s a Review of the Evidence. When Did the Coronavirus Arrive in the U.S.? Here’s a Review of the Evidence.
(about 4 hours later)
SEATTLE — In a county north of Seattle, two people who came down with respiratory illnesses in December now have antibodies for the coronavirus. In Florida, a public health official who got sick in January believes he had Covid-19.SEATTLE — In a county north of Seattle, two people who came down with respiratory illnesses in December now have antibodies for the coronavirus. In Florida, a public health official who got sick in January believes he had Covid-19.
And in California, a surprising discovery that an early-February death in San Jose was linked to the coronavirus has triggered a broader search for how that person was exposed.And in California, a surprising discovery that an early-February death in San Jose was linked to the coronavirus has triggered a broader search for how that person was exposed.
Those cases have contributed to growing questions about when the virus first reached the United States and how long it had been circulating by the time its arrival was publicly confirmed in Washington State at the end of February.Those cases have contributed to growing questions about when the virus first reached the United States and how long it had been circulating by the time its arrival was publicly confirmed in Washington State at the end of February.
While there was limited testing to uncover specific cases before then, researchers have other tools to trace the path of the coronavirus. That includes genomic sequencing of the virus to help scientists build an ancestral tree of cases, a re-examination of specific deaths and thousands of old flu samples that have been repurposed to look for the coronavirus.While there was limited testing to uncover specific cases before then, researchers have other tools to trace the path of the coronavirus. That includes genomic sequencing of the virus to help scientists build an ancestral tree of cases, a re-examination of specific deaths and thousands of old flu samples that have been repurposed to look for the coronavirus.
Here is a look at the evidence and what it shows:Here is a look at the evidence and what it shows:
It is possible, but it was most likely something else.It is possible, but it was most likely something else.
The Seattle area emerged as an early epicenter of the coronavirus outbreak at the end of February, but there is compelling evidence that, even there, the virus did not yet have much of a foothold compared with the flu, which had a particularly potent season.The Seattle area emerged as an early epicenter of the coronavirus outbreak at the end of February, but there is compelling evidence that, even there, the virus did not yet have much of a foothold compared with the flu, which had a particularly potent season.
A team that analyzes flu trends in the region has been able to review nearly 7,000 old flu samples collected from around the region in January and February, re-examining them for the coronavirus. All of the samples from January were negative. The earliest sample that tested positive was Feb. 20.A team that analyzes flu trends in the region has been able to review nearly 7,000 old flu samples collected from around the region in January and February, re-examining them for the coronavirus. All of the samples from January were negative. The earliest sample that tested positive was Feb. 20.
Based on that and later case counts, Trevor Bedford, who studies the evolution of viruses at the Fred Hutchinson Cancer Research Center in Seattle, and who was part of the flu study team, estimated that there were probably a few hundred cases in the area by that point in February.Based on that and later case counts, Trevor Bedford, who studies the evolution of viruses at the Fred Hutchinson Cancer Research Center in Seattle, and who was part of the flu study team, estimated that there were probably a few hundred cases in the area by that point in February.
But even that would still be a small fraction — perhaps less than 1 percent — of the many thousands of people who had flu symptoms at the time.But even that would still be a small fraction — perhaps less than 1 percent — of the many thousands of people who had flu symptoms at the time.
The U.S. first identified cases among travelers who had flown in from Wuhan, China, in the middle of January. Officials worked to contain them.The U.S. first identified cases among travelers who had flown in from Wuhan, China, in the middle of January. Officials worked to contain them.
There is some evidence that the virus began getting a bit of traction around the end of January. To seed that late-February emergence in the Seattle area, researchers believe the spread could have begun with a traveler who arrived in the region from Wuhan on Jan. 15, or it may have been another unknown case that arrived in the few weeks that came after.There is some evidence that the virus began getting a bit of traction around the end of January. To seed that late-February emergence in the Seattle area, researchers believe the spread could have begun with a traveler who arrived in the region from Wuhan on Jan. 15, or it may have been another unknown case that arrived in the few weeks that came after.
In San Jose, tissue sampling from a woman who died on Feb. 6 revealed that she was probably the first known person in the U.S. whose death was linked to the coronavirus — a strong sign that the virus may have been circulating in that part of Northern California in January.In San Jose, tissue sampling from a woman who died on Feb. 6 revealed that she was probably the first known person in the U.S. whose death was linked to the coronavirus — a strong sign that the virus may have been circulating in that part of Northern California in January.
But was it part of a large, previously unrecognized outbreak?But was it part of a large, previously unrecognized outbreak?
Dr. George Rutherford, a professor of epidemiology and biostatistics at the University of California, San Francisco, theorized that perhaps the woman, who worked for a company that had an office in Wuhan, was one of only a small number of people who contracted the virus at that time and that transmissions probably petered out for some reason. Otherwise, he said, the region would have seen a much bigger outbreak.Dr. George Rutherford, a professor of epidemiology and biostatistics at the University of California, San Francisco, theorized that perhaps the woman, who worked for a company that had an office in Wuhan, was one of only a small number of people who contracted the virus at that time and that transmissions probably petered out for some reason. Otherwise, he said, the region would have seen a much bigger outbreak.
“With that kind of early introduction, we should be seeing thousands of more cases,” Dr. Rutherford said.“With that kind of early introduction, we should be seeing thousands of more cases,” Dr. Rutherford said.
Dr. Sara Cody, the health officer for Santa Clara County, said local, state and federal officials were continuing to try to answer those questions.Dr. Sara Cody, the health officer for Santa Clara County, said local, state and federal officials were continuing to try to answer those questions.
There are other, less concrete signs of earlier infections. In Florida, where the first two official cases were announced on March 1, a state database now lists coronavirus cases in patients who may have had symptoms as far back as January. But the cases are all under investigation, and no one has confirmed that any of those patients had the disease that early.There are other, less concrete signs of earlier infections. In Florida, where the first two official cases were announced on March 1, a state database now lists coronavirus cases in patients who may have had symptoms as far back as January. But the cases are all under investigation, and no one has confirmed that any of those patients had the disease that early.
One of them is Raul Pino, the health officer for the Florida Department of Health in Orange County. He said recently that he suspected he had the virus in the first week of January.One of them is Raul Pino, the health officer for the Florida Department of Health in Orange County. He said recently that he suspected he had the virus in the first week of January.
Doctors in France have said that a patient’s sample from late December has since tested positive for the coronavirus. But so far, there is no comparable evidence of a similar case in the United States.Doctors in France have said that a patient’s sample from late December has since tested positive for the coronavirus. But so far, there is no comparable evidence of a similar case in the United States.
The strongest possible indicator so far is new evidence that emerged this week of two people in Snohomish County, Wash., who reported coronavirus-like symptoms in December. Both people later tested positive for antibodies, county health officials announced.The strongest possible indicator so far is new evidence that emerged this week of two people in Snohomish County, Wash., who reported coronavirus-like symptoms in December. Both people later tested positive for antibodies, county health officials announced.
But Dr. Chris Spitters, the county’s health officer, said that while it was possible that both people had the coronavirus in December — even before officials in China had reported a cluster to the World Health Organization at the end of the month — he was doubtful.But Dr. Chris Spitters, the county’s health officer, said that while it was possible that both people had the coronavirus in December — even before officials in China had reported a cluster to the World Health Organization at the end of the month — he was doubtful.
“It’s possible and frankly, I think, more likely that they had a non-Covid respiratory viral illness in December and subsequently had an asymptomatic or minimally symptomatic Covid infection subsequent to that,” Dr. Spitters said.“It’s possible and frankly, I think, more likely that they had a non-Covid respiratory viral illness in December and subsequently had an asymptomatic or minimally symptomatic Covid infection subsequent to that,” Dr. Spitters said.
Dr. Bedford said he also believed this was the more likely scenario, noting that up to half of people with coronavirus infections have no symptoms.Dr. Bedford said he also believed this was the more likely scenario, noting that up to half of people with coronavirus infections have no symptoms.
There could have been a tiny number of isolated coronavirus cases among travelers to the United States in December, Dr. Bedford said. But it is pretty clear that none of them spread.There could have been a tiny number of isolated coronavirus cases among travelers to the United States in December, Dr. Bedford said. But it is pretty clear that none of them spread.
In part, scientists can tell that by looking at the genomic fingerprints of each case. But another clue is the rapid rate at which the virus spreads, Dr. Rutherford said.In part, scientists can tell that by looking at the genomic fingerprints of each case. But another clue is the rapid rate at which the virus spreads, Dr. Rutherford said.
Updated June 12, 2020Updated June 12, 2020
So far, the evidence seems to show it does. A widely cited paper published in April suggests that people are most infectious about two days before the onset of coronavirus symptoms and estimated that 44 percent of new infections were a result of transmission from people who were not yet showing symptoms. Recently, a top expert at the World Health Organization stated that transmission of the coronavirus by people who did not have symptoms was “very rare,” but she later walked back that statement.
Touching contaminated objects and then infecting ourselves with the germs is not typically how the virus spreads. But it can happen. A number of studies of flu, rhinovirus, coronavirus and other microbes have shown that respiratory illnesses, including the new coronavirus, can spread by touching contaminated surfaces, particularly in places like day care centers, offices and hospitals. But a long chain of events has to happen for the disease to spread that way. The best way to protect yourself from coronavirus — whether it’s surface transmission or close human contact — is still social distancing, washing your hands, not touching your face and wearing masks.Touching contaminated objects and then infecting ourselves with the germs is not typically how the virus spreads. But it can happen. A number of studies of flu, rhinovirus, coronavirus and other microbes have shown that respiratory illnesses, including the new coronavirus, can spread by touching contaminated surfaces, particularly in places like day care centers, offices and hospitals. But a long chain of events has to happen for the disease to spread that way. The best way to protect yourself from coronavirus — whether it’s surface transmission or close human contact — is still social distancing, washing your hands, not touching your face and wearing masks.
So far, the evidence seems to show it does. A widely cited paper published in April suggests that people are most infectious about two days before the onset of coronavirus symptoms and estimated that 44 percent of new infections were a result of transmission from people who were not yet showing symptoms. Recently, a top expert at the World Health Organization stated that transmission of the coronavirus by people who did not have symptoms was “very rare,” but she later walked back that statement.
A study by European scientists is the first to document a strong statistical link between genetic variations and Covid-19, the illness caused by the coronavirus. Having Type A blood was linked to a 50 percent increase in the likelihood that a patient would need to get oxygen or to go on a ventilator, according to the new study.A study by European scientists is the first to document a strong statistical link between genetic variations and Covid-19, the illness caused by the coronavirus. Having Type A blood was linked to a 50 percent increase in the likelihood that a patient would need to get oxygen or to go on a ventilator, according to the new study.
The unemployment rate fell to 13.3 percent in May, the Labor Department said on June 5, an unexpected improvement in the nation’s job market as hiring rebounded faster than economists expected. Economists had forecast the unemployment rate to increase to as much as 20 percent, after it hit 14.7 percent in April, which was the highest since the government began keeping official statistics after World War II. But the unemployment rate dipped instead, with employers adding 2.5 million jobs, after more than 20 million jobs were lost in April.The unemployment rate fell to 13.3 percent in May, the Labor Department said on June 5, an unexpected improvement in the nation’s job market as hiring rebounded faster than economists expected. Economists had forecast the unemployment rate to increase to as much as 20 percent, after it hit 14.7 percent in April, which was the highest since the government began keeping official statistics after World War II. But the unemployment rate dipped instead, with employers adding 2.5 million jobs, after more than 20 million jobs were lost in April.
Mass protests against police brutality that have brought thousands of people onto the streets in cities across America are raising the specter of new coronavirus outbreaks, prompting political leaders, physicians and public health experts to warn that the crowds could cause a surge in cases. While many political leaders affirmed the right of protesters to express themselves, they urged the demonstrators to wear face masks and maintain social distancing, both to protect themselves and to prevent further community spread of the virus. Some infectious disease experts were reassured by the fact that the protests were held outdoors, saying the open air settings could mitigate the risk of transmission.Mass protests against police brutality that have brought thousands of people onto the streets in cities across America are raising the specter of new coronavirus outbreaks, prompting political leaders, physicians and public health experts to warn that the crowds could cause a surge in cases. While many political leaders affirmed the right of protesters to express themselves, they urged the demonstrators to wear face masks and maintain social distancing, both to protect themselves and to prevent further community spread of the virus. Some infectious disease experts were reassured by the fact that the protests were held outdoors, saying the open air settings could mitigate the risk of transmission.
Exercise researchers and physicians have some blunt advice for those of us aiming to return to regular exercise now: Start slowly and then rev up your workouts, also slowly. American adults tended to be about 12 percent less active after the stay-at-home mandates began in March than they were in January. But there are steps you can take to ease your way back into regular exercise safely. First, “start at no more than 50 percent of the exercise you were doing before Covid,” says Dr. Monica Rho, the chief of musculoskeletal medicine at the Shirley Ryan AbilityLab in Chicago. Thread in some preparatory squats, too, she advises. “When you haven’t been exercising, you lose muscle mass.” Expect some muscle twinges after these preliminary, post-lockdown sessions, especially a day or two later. But sudden or increasing pain during exercise is a clarion call to stop and return home.Exercise researchers and physicians have some blunt advice for those of us aiming to return to regular exercise now: Start slowly and then rev up your workouts, also slowly. American adults tended to be about 12 percent less active after the stay-at-home mandates began in March than they were in January. But there are steps you can take to ease your way back into regular exercise safely. First, “start at no more than 50 percent of the exercise you were doing before Covid,” says Dr. Monica Rho, the chief of musculoskeletal medicine at the Shirley Ryan AbilityLab in Chicago. Thread in some preparatory squats, too, she advises. “When you haven’t been exercising, you lose muscle mass.” Expect some muscle twinges after these preliminary, post-lockdown sessions, especially a day or two later. But sudden or increasing pain during exercise is a clarion call to stop and return home.
States are reopening bit by bit. This means that more public spaces are available for use and more and more businesses are being allowed to open again. The federal government is largely leaving the decision up to states, and some state leaders are leaving the decision up to local authorities. Even if you aren’t being told to stay at home, it’s still a good idea to limit trips outside and your interaction with other people.States are reopening bit by bit. This means that more public spaces are available for use and more and more businesses are being allowed to open again. The federal government is largely leaving the decision up to states, and some state leaders are leaving the decision up to local authorities. Even if you aren’t being told to stay at home, it’s still a good idea to limit trips outside and your interaction with other people.
Common symptoms include fever, a dry cough, fatigue and difficulty breathing or shortness of breath. Some of these symptoms overlap with those of the flu, making detection difficult, but runny noses and stuffy sinuses are less common. The C.D.C. has also added chills, muscle pain, sore throat, headache and a new loss of the sense of taste or smell as symptoms to look out for. Most people fall ill five to seven days after exposure, but symptoms may appear in as few as two days or as many as 14 days.Common symptoms include fever, a dry cough, fatigue and difficulty breathing or shortness of breath. Some of these symptoms overlap with those of the flu, making detection difficult, but runny noses and stuffy sinuses are less common. The C.D.C. has also added chills, muscle pain, sore throat, headache and a new loss of the sense of taste or smell as symptoms to look out for. Most people fall ill five to seven days after exposure, but symptoms may appear in as few as two days or as many as 14 days.
If air travel is unavoidable, there are some steps you can take to protect yourself. Most important: Wash your hands often, and stop touching your face. If possible, choose a window seat. A study from Emory University found that during flu season, the safest place to sit on a plane is by a window, as people sitting in window seats had less contact with potentially sick people. Disinfect hard surfaces. When you get to your seat and your hands are clean, use disinfecting wipes to clean the hard surfaces at your seat like the head and arm rest, the seatbelt buckle, the remote, screen, seat back pocket and the tray table. If the seat is hard and nonporous or leather or pleather, you can wipe that down, too. (Using wipes on upholstered seats could lead to a wet seat and spreading of germs rather than killing them.)If air travel is unavoidable, there are some steps you can take to protect yourself. Most important: Wash your hands often, and stop touching your face. If possible, choose a window seat. A study from Emory University found that during flu season, the safest place to sit on a plane is by a window, as people sitting in window seats had less contact with potentially sick people. Disinfect hard surfaces. When you get to your seat and your hands are clean, use disinfecting wipes to clean the hard surfaces at your seat like the head and arm rest, the seatbelt buckle, the remote, screen, seat back pocket and the tray table. If the seat is hard and nonporous or leather or pleather, you can wipe that down, too. (Using wipes on upholstered seats could lead to a wet seat and spreading of germs rather than killing them.)
Taking one’s temperature to look for signs of fever is not as easy as it sounds, as “normal” temperature numbers can vary, but generally, keep an eye out for a temperature of 100.5 degrees Fahrenheit or higher. If you don’t have a thermometer (they can be pricey these days), there are other ways to figure out if you have a fever, or are at risk of Covid-19 complications.Taking one’s temperature to look for signs of fever is not as easy as it sounds, as “normal” temperature numbers can vary, but generally, keep an eye out for a temperature of 100.5 degrees Fahrenheit or higher. If you don’t have a thermometer (they can be pricey these days), there are other ways to figure out if you have a fever, or are at risk of Covid-19 complications.
The C.D.C. has recommended that all Americans wear cloth masks if they go out in public. This is a shift in federal guidance reflecting new concerns that the coronavirus is being spread by infected people who have no symptoms. Until now, the C.D.C., like the W.H.O., has advised that ordinary people don’t need to wear masks unless they are sick and coughing. Part of the reason was to preserve medical-grade masks for health care workers who desperately need them at a time when they are in continuously short supply. Masks don’t replace hand washing and social distancing.The C.D.C. has recommended that all Americans wear cloth masks if they go out in public. This is a shift in federal guidance reflecting new concerns that the coronavirus is being spread by infected people who have no symptoms. Until now, the C.D.C., like the W.H.O., has advised that ordinary people don’t need to wear masks unless they are sick and coughing. Part of the reason was to preserve medical-grade masks for health care workers who desperately need them at a time when they are in continuously short supply. Masks don’t replace hand washing and social distancing.
If you’ve been exposed to the coronavirus or think you have, and have a fever or symptoms like a cough or difficulty breathing, call a doctor. They should give you advice on whether you should be tested, how to get tested, and how to seek medical treatment without potentially infecting or exposing others.If you’ve been exposed to the coronavirus or think you have, and have a fever or symptoms like a cough or difficulty breathing, call a doctor. They should give you advice on whether you should be tested, how to get tested, and how to seek medical treatment without potentially infecting or exposing others.
If you’re sick and you think you’ve been exposed to the new coronavirus, the C.D.C. recommends that you call your healthcare provider and explain your symptoms and fears. They will decide if you need to be tested. Keep in mind that there’s a chance — because of a lack of testing kits or because you’re asymptomatic, for instance — you won’t be able to get tested.If you’re sick and you think you’ve been exposed to the new coronavirus, the C.D.C. recommends that you call your healthcare provider and explain your symptoms and fears. They will decide if you need to be tested. Keep in mind that there’s a chance — because of a lack of testing kits or because you’re asymptomatic, for instance — you won’t be able to get tested.
It appears that early in the outbreak, one infection was spreading to about four other people, on average, with an incubation period for new infections of about four days. So a case seeded in December would rapidly quadruple through new generations, most likely growing exponentially to millions of cases from a single unbroken chain of transmission by the end of February. Researchers are not seeing any chains that appear to go that far back.It appears that early in the outbreak, one infection was spreading to about four other people, on average, with an incubation period for new infections of about four days. So a case seeded in December would rapidly quadruple through new generations, most likely growing exponentially to millions of cases from a single unbroken chain of transmission by the end of February. Researchers are not seeing any chains that appear to go that far back.
Modelers looking back at the growth of outbreaks elsewhere have reached similar conclusions. One estimated that New York’s outbreak could have begun with perhaps 10 infected people who contracted the virus sometime between the end of January to the middle of February, when the first cases of community transmission were identified and hospitals began seeing more cases.Modelers looking back at the growth of outbreaks elsewhere have reached similar conclusions. One estimated that New York’s outbreak could have begun with perhaps 10 infected people who contracted the virus sometime between the end of January to the middle of February, when the first cases of community transmission were identified and hospitals began seeing more cases.
The virus first emerged in Wuhan in December after a series of people developed symptoms of a viral pneumonia and an examination found that they had been infected with a new coronavirus.The virus first emerged in Wuhan in December after a series of people developed symptoms of a viral pneumonia and an examination found that they had been infected with a new coronavirus.
A group of researchers in China later examined the histories of the first 41 lab-confirmed cases at a Wuhan hospital, finding that many of them had connections to a seafood market. But the earliest case, in a person who developed symptoms on Dec. 1, had no connections to the market.A group of researchers in China later examined the histories of the first 41 lab-confirmed cases at a Wuhan hospital, finding that many of them had connections to a seafood market. But the earliest case, in a person who developed symptoms on Dec. 1, had no connections to the market.
The information suggests that if the virus did originate from the market, it was most likely circulating by November, early enough to reach that first person. Dr. Bedford said it was conceivable to him that the virus began as early as October, but that November was more likely.The information suggests that if the virus did originate from the market, it was most likely circulating by November, early enough to reach that first person. Dr. Bedford said it was conceivable to him that the virus began as early as October, but that November was more likely.
There is no evidence that it started elsewhere. The virus mutates an average of twice a month, something researchers can see in the genomic sequences of individual cases, and all of the cases in Wuhan show close genetic links.There is no evidence that it started elsewhere. The virus mutates an average of twice a month, something researchers can see in the genomic sequences of individual cases, and all of the cases in Wuhan show close genetic links.
All of the other thousands of cases that have been sequenced around the globe show the Wuhan version as an ancestor.All of the other thousands of cases that have been sequenced around the globe show the Wuhan version as an ancestor.
Several unfounded theories that have gained traction suggest that the virus was created or accidentally released in a lab somewhere. The Chinese government speculated that perhaps Americans brought the virus in to China. President Trump has suggested it came from a virology lab in Wuhan.Several unfounded theories that have gained traction suggest that the virus was created or accidentally released in a lab somewhere. The Chinese government speculated that perhaps Americans brought the virus in to China. President Trump has suggested it came from a virology lab in Wuhan.
Dr. Bedford said there was no evidence of genetic engineering in the virus, noting that it appeared to be a genetic outgrowth of a virus circulating among bats. It probably reached humans through an intermediate animal, such as a pangolin, he said.Dr. Bedford said there was no evidence of genetic engineering in the virus, noting that it appeared to be a genetic outgrowth of a virus circulating among bats. It probably reached humans through an intermediate animal, such as a pangolin, he said.
“There’s no hallmarks of it having been manipulated in a lab,” Dr. Bedford said. “I think that’s definitive.”“There’s no hallmarks of it having been manipulated in a lab,” Dr. Bedford said. “I think that’s definitive.”
He did not, however, rule out the possibility that some version of the virus being studied by scientists in Wuhan could have somehow escaped and spread from there. But he doubts that is the case. He said that the most prevalent theory about the virus’s origins — that it spread naturally among animals at a live animal market in Wuhan, then jumped to humans — was the most likely explanation.He did not, however, rule out the possibility that some version of the virus being studied by scientists in Wuhan could have somehow escaped and spread from there. But he doubts that is the case. He said that the most prevalent theory about the virus’s origins — that it spread naturally among animals at a live animal market in Wuhan, then jumped to humans — was the most likely explanation.