Coronavirus: Contact tracing fails to slow down spread in US forcing authorities to focus on mitigation instead
Contact tracing of "patient zero" for the outbreak in the US appears to have failed in slowing down the coronavirus in the country, according to a Bloomberg report.
With over 1,000 Americans confirmed with COVID-19, the situation in the country seems to be spiraling out of control.
Contact tracing -- where medical workers track down people who had been in direct contact with patients -- helps health workers get ahead of the virus, thereby helping them control the spread. On March 1, US Health and Human Services Secretary Alex Azar referred to contact tracing as a fundamental measure for tackling the outbreak.
And yet it proved weak: officials may have missed tracing many other possible contacts. This could explain why Washington has the highest number of cases in the US. Over 23 people have died of the disease and over 279 have tested positive in the state.
Patient Zero
Carrying the virus to the US was patient zero, who landed in Seattle on January 15 from Wuhan -- a city where the outbreak took off. He reportedly traveled from the airport with other passengers, unwittingly exposing others to the virus.
After complaining of slightly elevated temperature and a cough, the patient sought medical help on 19 January. The 35-year-old man took precautions before heading to a clinic in Seattle. He arrived at the clinic wearing a mask. "After learning about his travel, the clinic drew blood and took nasal and throat swabs, 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," says the report.
He tested positive for the virus on January 20, making it the first confirmed case in the country. Soon, doctors placed him in a biocontainment ward at Providence Regional Medical Center in Everett, Washington, a two-bed unit developed for the Ebola virus.
The hospital had taken every possible step to treat the patient while also ensuring nobody contracted the infection. They even had a robot to minimize human interactions.
As the virus kept doctors busy in the hospital, a group of health officials was given a mammoth task of tracking people who had come into contact with the infected patient. By identifying and isolating these people, experts believe, they can slow down the spread. It also helps experts piece together details of how the virus has been moving in the country.
Playing detective, the officials tracked down 60 people, who were then kept isolated. And yet, according to the report, the virus was still circulating freely. All of this indicates that the virus rendered containment strategies such as contact tracing futile.
The Bloomberg report said it was already too late before health officials acted. Someone may have picked up the virus between Jan. 15 and Jan. 19 before the traveler went to the hospital. The patient may have sneezed in the airport shuttle or on some surface and anyone on the shuttle may have contracted the infection.
Health officials can't identify these people.
“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,” George Diaz, who leads the infectious disease department at Providence, where the patient was treated, told Bloomberg.
According to reports, thousands of Americans have quarantined themselves after they were informed of possible exposure to the virus. In California, more than 9,900 travelers, who have returned to the US through San Francisco International Airport or Los Angeles International Airport, are also under self-quarantine.
Besides, other issues might have contributed to the increased spread in the country. The Centers for Disease Prevention and Control (CDC) had earlier produced some faulty test kits, leaving many without a diagnosis.
And hospitals were not prepared enough. Most notably, many cases of coronavirus emerged out of Kirkland's Life Care Center, where at least 19 people have died.
Is contact tracing futile now?
It worked against MERS, Vice President Mike Pence said, adding that he learned this from his earlier experience as governor of Indiana.
"I'm proud to say that the state of Indiana secured that patient, found out everyone they'd ever contacted. There were no additional infections, and that patient recovered. There was only one other MERS disease," he said at a White House briefing, referring to a case in Florida.
Further, MERS spreads only when people were sick. The new coronavirus, on the other hand, could spread even when a person is showing no or mild symptoms.
Transmission of the new coronavirus by people with only mild symptoms helps explain why there have been so many more cases of the new coronavirus than of MERS. Dr. David Heymann, professor of infectious disease epidemiology at the London School of Hygiene and Tropical Medicine, told CNN.
But is contact tracing effective when parts of the country are already seeing community spread? It is community spread when health officials find an infected person who has neither traveled to an affected country nor has had any contacts with those infected.
An increase in community spread indicates that there could be limits to contact tracing, Dr. Anthony Fauci, the top infectious disease expert at the National Institutes of Health, explained.
"We're seeing community spread, and whenever you see community spread, you can do contact tracing, but [with] more community spread it becomes logistically more difficult," he said Sunday on NBC's Meet the Press.
In these times, other strategies, such as working to have enough protective gear for health care workers and doing better infection control at nursing homes, may help, Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, told CNN.
He added, "At some point, we have to ask ourselves is it time to make a transition. I said six weeks ago, we are not going to be able to stop this. It's like trying to stop the wind."