White House Outbreak Shows Testing Alone Can’t Halt Covid Spread

(Bloomberg) -- When President Donald Trump, returning from the hospital suffering from Covid-19 and still infectious, waved to the cameras from the Truman balcony and doffed his protective mask, virologists everywhere gasped.  The moment crystallized for them just how badly Trump’s handlers had miscalculated by attempting to protect their boss soley with Covid tests.  

Trump, now at the center of a growing cluster of cases the White House, is Exhibit A of a strategy that’s becoming clear was destined to fail. Every day, more of his close contacts and one-time visitors are turning up positive for the novel coronavirus that has sickened more than 7 million Americans and killed more than 200,000.  And more cases are expected to emerge.

“None of us believed that testing alone was going to be a solution,” said Ashish Jha, a physician and dean of the Brown University School of Public Health, a long-time testing proponent. “Testing isn’t a silver bullet that solves all of this. It’s a really powerful tool, but it must be coupled with mask wearing and making sure people limit their contacts.”

Infection Control

Those by now commonplace precautions are even more critical with Trump’s return to the White House as a highly infectious patient, harboring the disease and possibly spreading it to those around him who are vulnerable.

“You have to think about infection control,” said Jessica Justman, associate director of the Center for Infectious Disease Epidemiologic Research at Columbia University’s Mailman School of Public Health. “You have to assume the person is going to continue to be contagious.”

Trump is likely to remain infectious until at least Wednesday, according to Justman, who said masking wearing and social distancing within the White House are critically important to avoid further spread.

Prior to the White House outbreak, visitors gathered in ever-growing numbers, first at Republican National Convention events held on the  South Lawn in August and then for Amy Coney Barrett’s nomination to the Supreme Court in the Rose Garden in September.  In many cases receptions and other events were held indoors, ripe for spreading the virus, doctors said.

“The testing approach the White House used to protect the President was akin to giving squirt guns to the Secret Service,” said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. “It made no sense.”

The White House primarily relied on Abbott Laboratories ID NOW, a test first granted an emergency use authorization by the U.S. Food and Drug Administration in March. It works as a molecular diagnostic that spots and amplifies even low levels of the virus found in swabs taken from the nose. The sample is placed in a piece of equipment about the size of a toaster over, then heated to crack open the envelope of the virus, allowing the genetic material to be amplified and detected.

Virus Shedding

Experts posit that the White House didn’t fully grasp that testing doesn’t work like a light switch, flicking on when a person becomes infected. No test is perfect, detecting it  with everyone with the disease and correctly ruling it out in others. It also takes time as the virus builds up in the body until it reaches a level where it can be detected. Many people may never develop symptoms of the disease even as they spread the disease to others.

“Sometimes testing gives people a false sense of security,” said Michael Ben-Aderet, an infectious disease specialist and associate medical director of hospital epidemiology at Cedars-Sinai Medical Center in Los Angeles. “Just because you test negative on one day, it doesn’t mean that you can’t get infected on another day. It doesn’t mean you haven’t been exposed to the virus.”

People generally start shedding virus about 48 hours prior to the start of symptoms, and they are usually the most contagious in those early days and for the first few days after they start feeling unwell.

“What this elaborates clearly is that a person can become infectious before they turn positive,” potentially infecting others for days before they know their status, said George Abraham, chair of the infectious disease board at the American Board of Internal Medicine and chief of medicine at Saint Vincent Hospital in Worcester, Massachusetts. “That’s why it’s important to mask at all times if one isn’t able to isolate or be more than six feet apart from others. Testing alone is not the solution.”

Viral Material

Trump’s advisers never seemed to fully understand that. 

“It’s important to keep in mind that anybody around the President is tested, and not only tested for Covid with a rapid test but they also have their temperature checked,” said Jason Miller, a spokesman for Trump’s re-election campaign, on “Meet the Press” on Sunday.

Abbott Labs, though, said it understands the limits of its own tests. 

“Tests discover the presence of coronavirus once there’s enough viral material in a person to be able to detect it,” said Abbott spokeswoman Darcy Ross. “No test detects the virus immediately after the person becomes infected.”

Testing is most effective when it’s done repeatedly, on the same people, Jha said. Many visitors to the White House, and others in the President’s orbit in different locations, got just one test. That leads to less protection. Just a handful of false negative results would allow the virus to penetrate the bubble, he said.

“Masks were politicized and became a way of dividing America,” Jha said. “It hampered the White House because if you were on the anti-mask side of this political fight, you showed your political loyalties by not wearing a mask. And all you were really doing was increasing your susceptibility to the virus.”

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