Volunteers from the University of Pennsylvania began the process of contact tracking with people who have been diagnosed with COVID-19 in Philadelphia.
“We do think that that contact tracing is essential to be able to safely reopen society,” said Philadelphia Health Commissioner Thomas Farley. “We have to try to contain this infection so that we don’t have to live like this, where everybody is separated from everybody else.”
When a COVID-19 case is confirmed, a tracer reaches out to the patient to find out who he or she has been in contact with in the days leading up to the diagnosis.
The effectiveness of this containment strategy is enhanced when it is used during the initial phases of an epidemic, but in the case of Philadelphia, cases developed exponentially and the Public Health Department lost the capacity to trace contacts.
Farley said a strategy like this would be most effective once new cases are down to about 50 per day.
The initiative is starting on a very small scale. Carolyn Cannuscio, director of research for the Center for Public Health Initiatives at the Perelman School of Medicine, said so far her team has trained a few dozen volunteers, most of them medical or nursing students, or students in the schools of public health or social work.
The volunteers are working with the team responsible for delivering positive COVID-19 results to prioritize those patients within Penn’s medical system deemed “high exposure risk” because they live in congregate settings, such as nursing homes, or because they work in high contact occupations.
The team at Penn is in contact with the city Health Department, to let it know when they begin reaching out to the people these patients have been in contact with.
The process includes the handling of key personal information to establish the tracing lines. The team then contacts the individuals who have been exposed, without revealing the identity of the person who exposed them. These individuals must be quarantined for two weeks in order to cut the chain of infection. That way, instead of everyone being forced to stay at home indefinitely, only those with known exposure would be, and for a shorter time.
According to a recent report from Johns Hopkins University, Wuhan, China, had 9,000 contact tracers for a city of 11 million, that’s one contact tracer for roughly every 1,222 people.
Applying that same ratio to Philadelphia, a city of 1.6 million, would mean training a team of 1,309 contact tracers. On a national level, Johns Hopkins estimates a need for 100,000 investigators. So far, Penn has trained 63.
Farley said the city would need to seek funding from state, federal and local governments to hire the necessary workforce, plus philanthropic donations.