Life after social distancing may involve apps that ask you to self-isolate after you’ve been near someone who tests positive for COVID-19.
Right now, many countries are fighting the spread of COVID-19 with the bluntest tool possible: widespread social distancing. To deny the virus the opportunity to hop between people, most of us are staying in, regardless of whether we’ve come into contact with the virus.
But social distancing, which has saved lives and eased the burden on hospitals, comes at a high cost. Lost jobs, closed businesses and a frozen economy have many people anxious for restrictions to be eased and for life to get back to normal.
If countries hit the restart button now, epidemiologists say that the virus will come roaring back, exploiting the fact that so many people are still susceptible. Until a vaccine arrives, two key measures will need to pick up the slack as social distancing is eased.
One is widespread, easily accessible testing (SN: 4/17/20). And for tests that come back positive, a second system must quickly identify people who may have been infected by that person to prevent further spread. That’s what is known as contact tracing.
Following the links
The bread and butter of infectious disease control for over a century, contact tracing is a targeted way of breaking a pathogen’s chain of transmission. When a positive case pops on the radar of public health officials, a contact tracer takes action, doing detective work to track down all the people that person has encountered, or even been near.
Then, the contact tracer notifies those contacts that they may have been exposed to the virus and asks them to quarantine for the incubation period of the virus (about two weeks for cases of COVID-19). Starved of new hosts, the epidemic fizzles out, and contact tracers keep tabs on the people who are potentially infected to see if they develop symptoms.
Contact tracing helped contain the SARS outbreak of 2003. More recently, it helped control the 2014 Ebola outbreak in west Africa. But people with SARS or Ebola spread the virus only when they’re clearly sick, making it easier to identify and isolate cases. COVID-19 is a different story. Infected people who don’t yet show symptoms, or never do, may account for nearly half of all transmissions (SN: 4/15/20), a factor that helped COVID-19 silently spread around the world at a vastly larger scale than these previous outbreaks.
