Fernando Silvas, chief epidemiologist for Santa Cruz County, oversees contact tracing for the county.  Photo Credit: Fernando Silvas

Contact tracing is one of the most important components of the public health response to COVID-19. For decades before the current crisis, tracers were tracking exposures during the HIV epidemic, for sexually transmitted diseases (STD’s) and for other highly contagious diseases such as tuberculosis (TB). One of the most significant victories in public health has been the eradication of smallpox in 1979. The World Health Organization (WHO) attributes this achievement not because every person was vaccinated, but because of extensive contact tracing.

The job of a contact tracer is to “convince someone to trust you enough to share the names of people they may have exposed,” said 

Fernando Silvas, the head epidemiologist at Santa Cruz County Health Services (SCCHS). The tracer’s role when calling people who have contracted COVID-19 is “helping them realize that getting sick isn’t their fault, that there is nothing to be ashamed of, and that they are providing a public health service by aiding us in our investigation.”

After building a rapport and enlisting names of people who the infected person may have exposed, “comes the sometimes long process of reaching out to these people, informing them of the exposure while maintaining Health Insurance Portability and Accountability Act (HIPAA) compliance, educating them, listening to their story, answering their questions, and sometimes trying to persuade them to take an exposure or recommendations seriously,” said Silvas. 

As of July 25, the team had made between 15,000 to 20,000 calls to contacts of confirmed cases. 

“Our investigators/tracers do not tell contacts who provided the information…If the confirmed positive case grants permission, then we will mention the name and their association, but not share medical details. It is very helpful when the case allows for their name to be revealed, because then the questions can be more straightforward, allowing us to relay and obtain more accurate information.”

Silvas joined SCCHS as the lead epidemiologist in late March 2020, soon after the first case of COVID-19 had been confirmed. A University of Arizona graduate in microbiology, Silvas had spent the last nine years working in the Pima County Health Dept. in environmental health, epidemiology and most recently in TB control and prevention. 

At the start of the pandemic, Silvas was the only investigator and tracer in SCCHS. As the caseload increased dramatically, particularly in late May, other staff joined to support contact tracing. Now there are 18 people working as both investigators and tracers on his team.

“In late May, through a good part of June, we were in a rough patch trying to keep up. The toughest part of the pandemic for me was trying to train a new crew while trying to manage the dramatic influx of information and phone calls coming our way. It made for some long hours and weekends,” said Silvas. 

The investigators and tracers “receive in-house training which includes reading up on latest CDC guidelines and COVID-19 information, they shadow an interviewer, and are observed on calls before beginning calls on their own,” said Silvas.  

The 18 staff members at SCCHS are trained to be both investigators and tracers. An investigator, said Silvas, “conducts the interview of the confirmed case, and a tracer calls and follows up with the people that may have been infected.“ A tracer monitors close contacts with at least three phone calls in the first week, said Silvas. 

“With our current staffing, our plan is for four to five investigators, with the remaining 13 or 14 as tracers…If case numbers jump, and contacts rise accordingly, making it difficult for tracers to keep up, an interviewer can assist tracers with contact follow up. In addition, Arizona Department of Health Services can take some of the contact tracing overflow as well. 

At this point with the numbers dropping there are approximately five cases per staff,” said Silvas. As of now, the County does not recommend or offer testing to close contacts of an infected person. “With ideal testing capacity, testing [close contacts] between days five and seven wouldn’t be a bad idea if it gives someone some peace of mind and rules out asymptomatic positives, but it would not be a clean slate,” Silvas said. “The virus can still manifest itself up to 14 days after exposure, so I would encourage people not to assume a negative test during this time period has cleared them…they would still be asked to continue quarantine precautions for the remaining days…if an individual in quarantine develops covid-like symptoms, it is a reason to test.”

Testing is not used to determine if someone is no longer infectious. “For our purposes, when someone has “recovered”, it means that, based on the investigation interview, and the information they provided during follow up calls, they have met state and CDC guidelines for release from isolation,” said Silvas. 

In mid-June, test results started to take sometimes up to seven to ten days to be processed. “The delay in obtaining test results does impact the ability to trace effectively,” Silvas said. “The later the result, the less time to ensure people are well informed of proper isolation or quarantine practices. If it’s too delayed, then it may be time for them to be released from isolation.” Late in July the County began its first testing blitzes with the expectation that results would return within 72 hours. 

Silvas’ message to the county residents is “please don’t go to work, school, etc. while sick. Don’t dismiss your “mild” symptoms or try to make yourself believe it’s something else. The reports are not hype. People are getting sick, people are losing their lives to COVID-19. We all have a responsibility to help keep our communities safe. It will take all of us to get through this.”