Question: I’ve read a few reports — this one, for example — suggesting that contact tracing isn’t working in the United States. Is that true? Is the United States so focused on individualism that we just can’t do contact tracing?
Answer: Contact tracing is time-consuming, skills-based, cultural-competency based, and requires cooperation from the public. It doesn’t work well in contexts where cases are rapidly increasing or where testing is limited/delayed. It’s difficult. Contact tracing is also a necessary component of our response to COVID-19, and in spite of the difficulties, we’ve had many successes.
What are contact tracing successes?
- Contact tracing limits community transmission. By quickly identifying clusters and isolating individuals, contact tracing limits the ongoing spread of the virus. The state of Massachusetts was an early adopter of widespread contact tracing and has seen steady declines in cases, test positivity rate, hospitalizations and other key metrics.
- Contact tracing gives us key data to build our evidence base on transmission risks and protections! Because of contact tracing, we know much more about risk of infection, particularly as it relates to location — indoor restaurants, bars, crowded parties. Additionally, our increasing knowledge of the role of airborne transmission and evidence of protection afforded by mask wearing come from the data collected through contact tracing.
- Contact tracing allows hotspot identification for increased public health enforcement. Contact tracing highlights locations that require enhanced protections for employees and customers (think: meat and poultry plants, crowded bars). In knowing the location of the outbreak, officials can implement harm mitigation plans, as described in the NY Timesby an Allegheny, PA official.
How does contact tracing work?
Once a person tests positive, a contact tracer gets in touch with them to inquire about where they have been and who they have been around (generally defined as being within 6 feet of for a period of 10–15 minutes or longer) during the presumed period of infection (e.g. last 14 days). The contact tracer then reaches out to everyone who was potentially exposed and asks them to self-isolate for 14 days after the exposure, monitor themselves for symptoms, and get tested. For any exposed person who has symptoms, the process starts all over again. CDC offers more details here and Partners in Health offers this helpful diagram (Figure 1).
What must be in place for contact tracing to work? (not a comprehensive list)
- Limited Community Spread. When cases are rapidly rising, it is exceptionally difficult to effectively contact trace. There are just too many infected individuals. Contact tracing is to be implemented at scale in the period when community transmission is largely under control and the goal is to keep outbreaks contained. We need extensive contact tracing in place as we start reopening. If the virus is spreading too quickly for contact tracers to handle all the contacts, then it’s considered time to go back towards shut-down, including re-entering earlier phases of re-opening.
- Widespread Testing. For contact tracing to work, we must first identify cases and those cases must be identified within a short timeframe. If an infected individual cannot get a test, they remain unknown to contact tracing efforts. Meanwhile, if an infected individual receives their test result many days after testing, the people exposed during their period of infectivity will have been told to self-isolate too late to slow/contain the spread.
- Trained, Skilled, Community-Base Workforce. Johns Hopkins offers a few suggested best practices for contact tracing, noting that contact tracers do not need to have special public health skills — like epidemiology or the like. Most importantly, contact tracers must be active listeners, curious, meticulous (detail-oriented), and from the community they are working with.
- Community Trust and Participation. Folks must be willing to respond when contacted and provide details to contact tracers. In some communities, building this trust can be exceptionally difficult. This is why the key workforce skills described above are so imperative. Also important is widespread communication to set expectations and build knowledge and acceptance. Community members also need support, which means that wrap-around programs — to help people who are self-isolating receive food and medication, for example — must also be established.
What about American Exceptionalism?
The idea of American exceptionalism in the context of contact tracing, is akin to exceptionalism in the context of masking. We know that masking is necessary for limiting the spread of the virus. And just because we’re having trouble getting all Americans to wear masks doesn’t mean that we abandon the strategy. If anything, it means we invest more in campaigns to get Americans to wear face masks! In fact, after the White House Coronavirus Task Force shared CDC’s recommendation that all Americans wear face coverings when outside their homes back in early April, mask wearing increased from 61% to 74%. More can and should be done — to promote mask wearing and effective contract tracing! We must invest the resources for states and localities to hire, train, and manage contact tracing workforces while we must also invest the resources in educating the public, educating businesses, and building new social norms that bolster support for contact tracing efforts (including, for example, collecting contact information of clients to share with contact tracers in the event of an infection). This is not an insurmountable problem! We can contain the virus!
Figure 1. Contact Tracing Public Communication
