Cambridge's Disease Detectives Aim to Break the Chain of COVID-19 Transmission

Hundreds of Cambridge residents have learned they were infected with COVID-19 or had been exposed to the new coronavirus after getting a call from public health nurses from the Cambridge Public Health Department (CPHD). Thousands more have received calls from CPHD staff informing them of negative test results.

The phone calls are part of a massive behind-the-scenes effort to stop the chain of transmission of COVID-19.

The public health nurses lead a team that reaches out to every infected resident—also known as a case—providing them with support and guidance on how to isolate. They also try to identify and connect with everyone the person was in close contact with while infectious, a process known as contact tracing. The team checks in frequently with cases and contacts in isolation or quarantine, making sure they have enough food and other necessities, are monitoring their health, and are taking precautions to protect others in their household.

“The vast majority of residents have conscientiously and often cheerfully assisted us in this communicable disease investigation work during the COVID-19 pandemic,” said Shamsher Bam, RN, interim lead of the department’s public health nursing program.

The department’s public health nurses have extensive experience in case investigation and contact tracing, a specialized field that requires a mix of medical knowledge, detective skills, cultural sensitivity, and the ability to listen to and gain trust of people who may be reluctant to cooperate. When COVID-19 cases surged in April, the department recruited CPHD school nurses, recently retired CPHD public health nurses, and outside staff from the Commonwealth’s Community Tracing Collaborative to join the team.

The Community Tracing Collaborative (CTC) is assigned the more straightforward cases, while the health department handles the complex cases, which include residents in long-term care facilities, hospitalized patients, infected health care workers, patients over 70, and patients believed to be infected through a cluster event.

By early August, the two teams had reached out to over 1,200 positive cases, which was split among CPHD (around 75% of cases) and the CTC (around 25% of cases). CPHD identified about 470 contacts with Cambridge residents, and the CTC identified about 250 contacts with Cambridge addresses.

Learn more about the Commonwealth's CTC.