Here's How Coronavirus Contact Tracing Works in Massachusetts

Update: Gov. Charlie Baker said Thursday that the state has connected with nearly 14,000 confirmed cases and reached out to 7,500 of their close contacts since April 12.

It’s been a month since Gov. Charlie Baker announced a dramatic expansion of efforts to reach everyone who tests positive for the coronavirus, make sure they are in isolation and then track and test all of their close contacts to stop the spread.

It's called contact tracing and Baker says it's a key piece of his strategy to control the coronavirus and reassure the public.

“From our point of view, that’s a must-do with respect to anything that looks like a reopening of the commonwealth or a move toward opening the economy,” he said during a press briefing last month.

Here’s a breakdown of how it’s working so far, the main players and the key components:

Starting With The Infected Person

Contact tracing starts with a case. The Massachusetts Department of Public Health (DPH) gets the name of a resident who tests positive for the coronavirus and loads that person’s information, including where they live, into a state database called the Massachusetts Virtual Epidemiologic Network, or MAVEN.

The person’s local board of health sees that case and decides whether to investigate it or send the case to the statewide Contact Tracing Collaborative (CTC), run by Partners In Health (PIH). Massachusetts has contracted with PIH to manage the contact tracing operation, which will be statewide by the end of this week.

A case investigator calls the person who’s tested positive to check in. They discuss his or her symptoms and medical care, answer questions about the virus and explain the need to isolate from other people for 10 days after the first sign of symptoms. State guidance includes remaining in isolation for 72 hours after any fever and respiratory symptoms end.

Isolation means not sharing a bedroom or bathroom with another person, not sharing towels or bed sheets and washing laundry separately from others. The state gives detailed instructions on how to isolate.

If the person who is positive can’t isolate at home or doesn’t have a home, the CTC provides space at an isolation site. Residents with mild to moderate symptoms are monitored and fed.

Some communities have opened their own isolation sites. For example, Chelsea, Revere, Somerville and Lynn are using a Quality Inn as an isolation site. Chelsea City Manager Tom Ambrosino says he is hopeful that the Federal Emergency Management Agency will reimburse them for 75% of expenses tied to running the site, “but no guarantees.”

The Inn’s medical director, Dr. Dean Xerras, says guests are released when they've met the state's and the isolation site's criteria: seven days after the person first experienced symptoms, 72 hours after their last fever or respiratory symptom and after they’ve tested negative twice, with 24 hours between tests.

Finding The Person's Close Contacts

The case investigator also asks the person infected with the coronavirus for the names of recent close contacts. A close contact is anyone who was within six feet of the infected person for more than 15 minutes within at least two days of their positive test.

The case investigator gives the names of those identified as close contacts to a contact tracer. In the statewide system, investigators supervise teams of up to six contact tracers. Teams run by local boards of health vary in size.

Contact tracers attempt to call each close contact and tell them they were likely exposed to the coronavirus. The tracers help contacts arrange to be tested. Each close contact is asked to remain at home, in quarantine, for 14 days.

A close contact is anyone who was within six feet of the infected person for more than 15 minutes within at least two days of their positive test.

Quarantine is the step for anyone who is either waiting for a test result or has a negative result. Even those who test negative must quarantine, because they may have been exposed to the coronavirus. They must stay away from others because symptoms may not appear for 14 days.

Quarantine is slightly less strict than isolation. If possible, people in quarantine should avoid sharing a bedroom, bathroom or laundry with others. In both cases, the goal is to refrain from contact with anyone else until a doctor confirms that you are not contagious.

There is no organized network of quarantine sites in Massachusetts for people who don’t have a separate room at home or don’t have a home. Xerras says the isolation site in Revere also accepts people from Chelsea, Revere, Somerville and Lynn who test negative, but were exposed to the coronavirus. These people, if they are referred by a doctor, are considered “COVID-19 presumed.” The state recommends separate facilities for quarantine and isolation, but has guidance on how to include both groups in a single site.

Public health leaders say thousands of Massachusetts residents may need help to successfully remain in isolation or quarantine. That’s the job of the resource coordinator. This person works within a specific region that could include several towns. The resource coordinators help arrange food deliveries, medical care and other support services.

Far Fewer Close Contacts Than Expected

So far, the state says the average number of close contacts reported by residents who test positive for the virus is just two, fewer than the 10 investigators expected.

“Social distancing has been important in reducing contacts,” said John Welch, the director of partnerships and operations for the MA Covid Response project at Partners In Health. “So we need to be very conscientious about what will happen when those restrictions are loosened because the number of contacts will go up.”

The Main Players

Local boards of health: “Every city and town in Massachusetts with cases is doing contact tracing in some form or another,” Sigalle Reiss, president of the Massachusetts Health Officers Association, said in an email.

Reiss said capacity varies by municipality, but many have used state funds provided during the pandemic to hire more nurses or have pulled school nurses in to assist with contact tracing. Hundreds of public health students have also worked with cities and towns to trace 1,972 cases.

Partners In Health: PIH has hired more than 1,200 people as supervisors, case investigators, contact tracers and care resource coordinators. More than 100 Blue Cross Blue Shield of Massachusetts employees joined the effort along with more than 300 staff members from 36 community health centers in the state.

As of May 5, PIH says staff are working with more than 17,000 people — those who’ve tested positive and their close contacts. There are thousands more cases that local boards of health are handling.

The state has reported 70,271 residents who’ve tested positive for the coronavirus as of May 5, a number that WBUR is tracking here.