(Bloomberg Businessweek) -- The man who would become Patient Zero for the new coronavirus outbreak in the U.S. appeared to do everything right. He arrived Jan. 19 at an urgent-care clinic in a suburb north of Seattle with a slightly elevated temperature and a cough he’d developed soon after returning four days earlier from a visit with family in Wuhan, China.

The 35-year-old had seen a U.S. Centers for Disease Control and Prevention alert about the virus and decided to get checked. He put on a mask in the waiting room. After learning about his travel, the clinic drew blood and called state and county health officials, who hustled the sample onto an overnight flight to the CDC lab in Atlanta. The patient was told to stay in isolation at home, and health officials checked on him the next morning.

The test came back positive that afternoon, Jan. 20, the first confirmed case in the U.S. By 11 p.m., the patient was in a plastic-enclosed isolation gurney on his way to a biocontainment ward at Providence Regional Medical Center in Everett, Washington, a two-bed unit developed for the Ebola virus. As his condition worsened, then improved over the next several days, staff wore protective garb that included helmets and face masks. Few even entered the room; a robot equipped with a stethoscope took vitals and had a video screen for doctors to talk to him from afar.

County health officials located more than 60 people who’d come in contact with him, and none developed the virus in the following weeks. By Feb. 21, he was deemed fully recovered. Somehow, someone was missed.

All the careful medical detective work, it’s now clear, wasn’t enough to slow a virus moving faster than the world’s efforts to contain it. In February, firefighters in Kirkland, Washington, began making frequent visits to a nursing home where residents complained of respiratory problems —evidence of continuing transmission that burst into public view a week ago when officials announced the first in a series of deaths at the facility from Covid-19, the disease caused by the virus.



The Seattle area, which had 118 infections and 18 deaths as of Sunday, is now the center of the most severe known U.S. outbreak as virus fears roil world markets, shut down commerce and schools and cause people to stock up on food and medicine. “We are past the point of containment and broad mitigation strategies—the next few weeks will change the complexion in this country,” Scott Gottlieb, a former commissioner of the Food and Drug Administration, said Sunday on CBS’s Face the Nation.

This reconstruction of how the virus spread around Seattle, based on interviews with health-care providers, first responders, relatives of patients and academic researchers, offers lessons to places like Florida and California that are now reporting their first deaths. There were excruciating missed opportunities, especially at the nursing home. One shortcoming was a lack of testing in a critical six-week window when the virus was spreading undetected. Even recently, some patients said, hospitals weren’t taking enough precautions to protect staff and others from infection.

Ultimately, Seattle’s experience shows the futility of travel bans in the face of a pathogen that’s sickened more than 110,000 people and killed more than 3,800 since authorities in China on Dec. 31 reported a mysterious viral pneumonia linked to an open-air seafood market. Governments are now bowing to the reality of unprecedented, economy-killing measures seen as Draconian just weeks ago. Italy early Sunday restricted travel in and out of the region surrounding Milan and ordered closings of schools, museums, pools, gyms and theaters, among other public places.

< PREVIOUS SLIDE SLIDE 1 of 5 NEXT SLIDE > Seattle Area Continues To Implement Precautions To Curb Outbreak Of Coronavirus © Photographer: Karen Ducey/Getty Images

While a hard-and-fast lockdown of a U.S. city like Seattle is hard to imagine, something similar might happen, said Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases. “You don’t want to alarm people, but given the spread we see, you know, anything is possible,” he told Fox News.

On Jan. 15, when the traveler to Wuhan who became the first known U.S. case returned to Seattle-Tacoma International Airport, he took group transportation from the airport with other passengers, county officials have said.

At the time, 41 people in Wuhan had been diagnosed with the novel coronavirus, so named for the crownlike spikes that help them invade cells, and Chinese officials said the threat of human-to-human transmission was low. A CDC notice advised Americans who’d been in Wuhan and felt sick to seek care.

On Jan. 17, the U.S. began checks of passengers from Wuhan at airports in New York, Los Angeles and San Francisco.

Two days later, the recent arrival from Wuhan visited the urgent-care clinic in Snohomish County, Washington, and the intensive response began. In retrospect, it was already too late. Some researchers who’ve traced the viral genomes of patients around the world now believe someone else in the area picked it up between Jan. 15 and Jan. 19, before the traveler went to the hospital. He might have sneezed in the airport shuttle or on some surface—all but impossible for health workers to trace.

“This virus is more contagious than the flu, so any sort of exposures before he got to the hospital would be certainly of high concern,” said George Diaz, who leads the infectious disease department at Providence, where the patient was treated.

By Jan. 30, the patient’s symptoms had resolved, according to a New England Journal of Medicine paper. Snohomish County officials allowed him to leave home isolation three weeks later.

Early in February, the CDC began shipping test kits to health officials around the country as news out of Wuhan grew alarming—tens of thousands more sickened and a virtual lockdown imposed to keep people in their homes.

Outbreaks hit Iran, Italy and South Korea. More U.S. cases were reported in places including Illinois, California and Massachusetts, suggesting other travelers may have brought it home with them. For every dozen cases the U.S. caught, it probably missed 20 or 25, estimated Marc Lipsitch, an epidemiology professor at the Harvard T.H. Chan School of Public Health. “It may be, for example, that Seattle got unlucky and had an early introduction that did take off into a chain of transmission, and other places that did nothing different might have had better luck,” he said. “It’s quite possible that we’ll see some places with lots of cases once we start testing.”

Testing around the U.S. was hampered when local officials reported flaws in the kits the CDC sent. Replacements didn’t come until weeks later, which left most hospitals and clinics short of tests. Shifting guidelines for who should get the few tests available also confused hospitals, Diaz said.

At the time, there had still been just the single case reported in Seattle. Trevor Bedford, a Harvard-trained researcher and viral genome expert at the city’s Fred Hutchinson Cancer Research Center, wondered why. He had spent weeks analyzing genomes of patients from around the world, tracing minor mutations to deduce how Covid-19 emerged and spread.

The early work found that infections were doubling roughly every six days, and that for every three to four rounds of transmission—or once every 20 to 30 days—one minor mutation was occurring, Bedford said in a Feb. 13 interview. “We are watching very carefully for more local transmission,” he said at the time.

They soon found it: a teenager with mild symptoms who attended a high school about 15 miles from where the first case was identified—someone who wouldn’t have been tested because he or she didn’t meet the criteria. But the results showed up in the Seattle Flu Study, a project on which Bedford is a lead scientist.

The new case, announced Feb. 28, was genetically identical to the original except for three minor mutations in the virus. And it contained a key genetic variant that was present only in two of 59 viral samples from China. This type of circumstantial evidence stops just short of proving a chain of transmission. It's possible the Washington cluster didn't derive from the known Patient Zero, but another case that came into Washington the same time and went undetected. Still, Bedford calculated a 97 percent probability the new case was a direct descendant—one that hadn’t been spotted because of the narrow testing at that time, Bedford wrote in a March 2 post.

“This lack of testing was a critical error and allowed an outbreak in Snohomish County and surroundings to grow to a sizable problem before it was even detected,” he wrote.

The consequences were deadly for residents of Life Care Center, a nursing home in the Seattle suburb of Kirkland that houses elderly and often very sick patients. February was an unusually busy period for 911 calls to the home, said Evan Hurley, a Kirkland firefighter and union representative. The number went from seven in January to 33 for February and the first few days of March, he said, citing call logs later used to track which staffers needed to be quarantined.

Firefighters weren’t always wearing masks; sometimes the calls were for a nosebleed or some other problem, Hurley said. But by late February, he recalled, a lieutenant remarked about the number of recent visit to Life Care for breathing issues and fever. A captain shared the concern with the county. Then, on Feb. 28, came word that a patient transferred from the home had Covid-19. The fire department declared the facility a “hot zone” requiring full protective gear. An initial group of 17 firefighters was quarantined.

The next day, state officials announced the first death in the U.S. attributed to the new coronavirus and said that more than 50 people associated with Life Care were sick and being tested. The facility’s low-slung building in a nondescript part of town dotted with condos became the center of an unfolding health crisis. Authorities dramatically increased public warnings—while, families contended, doing little to save people in the home. “They are being left to be picked off one by one by this disease,” a relative, Kevin Connolly, told television reporters outside.

King County officials quickly moved to purchase a motel and set up modular housing to isolate patients, a jarring escalation. Within days of the first deaths, they advised people older than 60 to stay away from public places, while avoiding a total ban on big events. A comic-book convention planned for downtown Seattle held out until Friday before canceling. “We are determined to protect those who are most vulnerable—our older residents, those with compromised immune systems—and, in doing those things, we also want to protect our economy,” King County Executive Dow Constantine told reporters.

Giant companies like Amazon.com Inc. and Microsoft Corp. ordered Seattle-area staff to work from home if possible, and the University of Washington shifted to online classes for the remainder of the quarter ending March 20. As of Sunday, King County had reported 83 cases and 17 deaths, all but one tied to the nursing home.

The challenge for the health system is that in the vast majority of cases, symptoms remain mild—but some percentage of people require hospitalization.

At Providence in Everett where Patient Zero was treated, bed space could become an issue. Last week, the hospital started a program to discharge stable patients, Diaz said. They’re sent home with a thermometer and an oximeter, a measure of respiratory health. Readings are transmitted to Providence and if the patient’s condition worsens, they can quickly be returned to the hospital. Ten patients were in the program Sunday, Diaz said.

Still, some people complain area hospitals aren’t consistently following protocols to isolate possible cases. On a doctor’s orders, Alicia Hansen on Tuesday took her mother, who’s had cancer multiple times, to the Swedish Hospital First Hill emergency room after she developed fever and breathing difficulties. She and her mother live together not far from the nursing home in Kirkland. According to Hansen, some hospital staff were in and out of her mother’s room without masks in their first 45 minutes at the facility. Hansen herself, who could have been exposed to the virus, was mixed with the general population in a waiting room while her mother was treated and tested for Covid-19. The test came back negative, but her mother died Saturday.

At Life Care on Friday, another 15 people were hospitalized within 24 hours. Hurley, the Kirkland firefighter, has moved some of the patients himself over the past week.

Another concern: Life Care also serves as a short-term rehabilitation center for some patients. In the weeks before the spread of the virus was known, Life Care discharged patients to their homes or other nursing facilities, Hurley said. (Life Care said the first patient later diagnosed was picked up from the home Feb. 19. Hurley says it may have been as early as Jan. 22, based on call logs.)

“We don’t think we are anywhere near the end of this,” he said. “This spread is not limited to Life Care.” On Friday, a nursing home in Issaquah, a suburb east of Seattle, said a resident recently transferred there had tested positive for Covid-19. A Seattle retirement community announced a single case.

All told, 31 Kirkland firefighters—almost a third of the department—in addition to 10 from other communities as well as some relatives have been quarantined, adding to the stress on emergency teams.

Bedford, the genome expert, is working with University of Washington researchers to understand the extent of the spread. Last week, the university started using its own virus test, a modified version of one created by the World Health Organization. When a positive result is found in a sample, the researchers perform a second round of tests to sequence the viral genome.

Pavitra Roychoudhury, a university researcher in charge of sequencing, said technicians have been working late into the night to complete as many samples and sequences as possible. She puts her toddler to bed and then logs back into her computer.

On a call with reporters on Monday, Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, called Bedford's theory "an interesting hypothesis" but said other possibilities have not been ruled out. "There are alternate explanations of the same findings," she said. There may have been a "secondary seeding" in the community, she said, as more recent cases in Washington match viral sequences posted in China.

So far, Bedford has reported, sequencing still suggests the transmission is related to the original patient—and the number of active infections could reach 1,100 by March 10 and 2,000 by March 15.

What’s more, the state's early cases may have seeded infections now exploding on the cruise ship Grand Princess off California’s coast, he tweeted this week. Researchers from the University of California at San Francisco have said the viral strain from a patient infected on the ship is similar to the cluster circulating in Washington state. —With assistance by Emma Court and Michelle Fay Cortez

To contact the authors of this story: Peter Robison in Seattle at robison@bloomberg.netDina Bass in Seattle at dbass2@bloomberg.netRobert Langreth in New York at rlangreth@bloomberg.net

To contact the editor responsible for this story: Timothy Annett at tannett@bloomberg.net, Flynn McRobertsStephen Merelman

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