The idea of contact tracing is nothing new. It has been practiced for decades to help stop the spread of infectious diseases such as smallpox and HIV. It has been taught to public health professionals for decades. However, with the global explosion of the COVID-19 pandemic in 2020, it has emerged as a key strategy to control the spread of infection.
The practice of interviewing people who have COVID-19 is an effort to determine where they may have gotten infected and who they were within close contact with while infectious. It is widely accepted as one way to interrupt disease spread. In its recently released COVID-19 Testing and Tracing Action Plan, the Rockefeller Foundation lists increasing the use, speed, public trust, and support services for contact tracing as one the 10 action steps essential for defeating the disease.
The Basics of Tracing
The steps for proper contact tracing sound simple, but can become quite complex depending on the severity of the disease, the number of close contacts, the willingness of the public to participate, and the availability of human capital to undertake these steps:
- Identify a person with the disease (i.e., a “case”)
- Interview the person and determine how they may have been exposed (“Where were you and who were you with the past xx days?”)
- Explain the importance of staying away from others who may catch the disease (i.e., “isolation”) [Note: For COVID-19, the length of isolation is 10 days from the onset of symptoms and at least 24 hours after the last fever that was not treated with medication.]
- Determine who they have been close to and may have passed the disease on to (i.e., a “contact”) [Note: A person with COVID-19 is considered infectious two days before they become symptomatic and for at least 10 after symptoms emerge.]
- Reach out to all contacts identified by the case and encourage them to stay away from others for 14 days after the last exposure to the case (i.e., “quarantine”); as opposed to “isolation,” which has a similar effect, remaining at home and separated from others, including family members as much as possible [Note: The Department of Health and Human Services notes that isolation separates sick people with a contagious disease from other people who are not ill, while quarantine separates and restricts the movement of people who have been exposed to a contagious disease, such as family members, to see if they become sick. Those contacts may have been exposed to a disease and not know it, or they may have the disease and not show symptoms.]
Given the virulence of COVID-19, most people in the United States know about isolation and quarantine. Although remaining sequestered in their homes for two weeks is no easy task, most people who have been told they are infectious agree to comply.
The Centers for Disease Control and Prevention (CDC) reports that COVID-19 spreads mostly person-to-person through respiratory droplets, which result when the infected person coughs, sneezes, speaks, etc. Spread is more likely when people are within six feet of one another because the virus-laden droplets are more likely to reach the mouths, noses, or eyes of nearby people.
Preventing the Spread of Disease
Keeping infected people away from others is how public health specialists believe the disease can be brought under control. The global public health initiative Resolve to Save Lives calls this “Boxing in” the disease by limiting the number of people it can infect. The concept of boxing in the disease involves a four-step process:
- Expand and prioritize testing
- Isolate all infected people
- Identify those who have been in contact with infected people
- Quarantine those contacts
According to Dr. Tom Frieden, the head of Resolve to Save Lives and former director of the CDC, “All four are crucial; if any step is lacking, the virus can escape and spread explosively again.” Contact tracing is a key element in these steps.
When people test positive for COVID-19, they are contacted and given their results. They are also told the importance of isolating from others for a set number of days. In late July 2020, the CDC updated its recommended length of isolation to 10 days from the onset of the first symptom and at least 24 hours after the last fever that was not treated with medication.
After receiving a positive confirmation, contact tracers reach out to cases in order to collect comprehensive health data, such as the symptoms they experienced, lists of people with whom they had close contact before becoming ill, and others they may have passed the disease on to. Since COVID-19 patients are infectious and can shed the virus two days before they develop symptoms, they may unknowingly pass it on to others.
Studies indicate the level of infectiousness peaks early in the disease. This makes it even more important to quickly identify who may have been in contact with a case before the case became symptomatic and alert those contacts to the potential of infection.
As the number of COVID-19 patients increases rapidly, the requirement for qualified contact tracers has also increased, but the supply has not. Most local health departments have historically relied on full-time staff, often nurses, to do the new contact tracing work along with their normal job responsibilities. As the number of cases grow, departments often cut back on the work normally performed by their nurses and others in order to take on these new responsibilities.
Some departments have turned to volunteers to do the contact tracing work, sometimes using members of existing groups such as their Medical Reserve Corps – a program modestly supported by the federal government through the Office of the Assistant Secretary for Preparedness and Response. These volunteer groups are comprised of residents who have offered to provide support to local public health efforts in more than 800 communities. Many are retired medical professionals whose experience makes them ideal for the job, but their volunteer status may limit the number of hours or days they can be expected to work. The volunteer management expertise also varies dramatically among the groups. The advantage of this method is to maintain close control over the volunteers, but this is a resource-intensive effort, as the volunteers must be trained and managed.
Some health departments have hired consulting organizations to handle some or all of their contact tracing. Benefits may include:
- Recruiting, training, and management are handled by the firm, not the health department.
- Costs are controlled since no additional benefits or overtime pay is required.
- The department maintains control over its data.
- HIPAA compliance is maintained by the consultant.
- CARES Act funding may be used.
Developing a Program – One Company’s Lessons Learned
One Kansas county engaged the Bio-Defense Network to conduct contact tracing. In the first month of work, the company was able to reach 367 people who had tested positive for COVID-19. The calls took 481 hours to complete – an average of 1.3 hours per call – which included time for quality assurance.
By June, the company positioned itself as a clearinghouse for qualified people wishing to help with contact tracing and departments needing the support. The model is simple: the company recruits, screens, and engages people qualified to do the work, pays them a modest hourly rate, and then assigns them to departments that need the service. The company collects an hourly fee and manages them on a daily basis.
Because the work is done by telephone, the contractors can be anywhere and can work for any department in the nation. The contact tracers work from their homes or dormitories, and the company tracks and reviews their work.
Recruiting part-time contact tracers has been done through colleges and universities with a focus on public health, nursing and allied health graduate students, recent graduates, and alumni, many of whom have been unable to locate internships or other jobs due to the pandemic and the associated economic downturn. For current students, the experience has proved valuable, with some universities awarding academic credit for internship or offering credit for clinical hours worked as part of the program.
As the nascent program was rolled out in the early summer, the company was faced with the challenge of recruiting contact tracers on the expectation it would generate sufficient business for them, even before it had finalized any agreements with a health department. Once it had begun working for a county in Kansas, it quickly recognized another unexpected need: Spanish-speaking contact tracers. Kansas officials noted that, although there was a relatively modest Hispanic population, nearly half of the patients who tested positive early in the process were Hispanic. By contacting officials at the Medical Campus of Miami-Dade College, the company was able to recruit a number of bilingual graduates from a special contact tracing course being offered for Spanish speakers.
Scheduling for contact tracers was also a challenge for the company, since its student contact tracers were not generally interested in working more than 12-16 hours a week, and many were not willing to commit to work on weekends, when many cases required calls. To address this challenge, contact tracers were asked to commit to four-hour blocks and were encouraged to work on sequential days of the week. This was especially important since few contacts answer telephone calls from unknown numbers. As such, contact tracers often were forced to leave messages that may not be returned until the next day.
As the fight against COVID-19 continues nationally, it is clear the need for qualified contact tracers will remain strong for months to come. Innovative methods of meeting this need – either within or outside the organization – will be required. Develop a contact tracing program that fits the needs and addresses the challenges of the population that is being identified.
David Reddick is chief strategy officer and co-founder of Bio-Defense Network, a public health preparedness consultancy which has worked with more than 40 local public health departments over the past nine years. He also was co-founder of PandemicPrep.Org, a non-profit organization that conducted dozens of public workshops and programs on preparing for pandemics such as COVID-19.
John Anthony is senior consultant for Bio-Defense Network and program manager of its contact tracer program. He has been a Medical Technologist certified by the American Society of Clinical Pathologists for more than 20 Years and served as a Laboratory Manager for ten years and an Infection Control Infection Preventionist. He won a NACCHO Model Practice Award for his Public Health Liaison Project in 2007, and a NACCHO Certificate of Promising Practice for Bio-Defense Network in 2012. His work has also been recognized by two Bi-State Infectious Disease Conference Partnership Awards (NoFluForYou Project in 2011 and Closed POD Network with Bio-Defense Network) in 2013. He formerly served as the Laboratory Services Coordinator, Public Health Liaison Program Manager, Emergency Preparedness Manager for the St. Louis County Department of Public Health, co-chair of the STARRS Public Health Committee and Finance Committees for the STARRS UASI region, secretary of the regional radiological MRC and member of the region’s ESF-8 planning committee.