Contact tracing is used to control an outbreak of infectious viruses and diseases such as COVID-19. Tracing back who was in contact with a patient provides information on possible new cases as well as information about the virus itself. In this time of uncertainty, it is useful to have multiple options of moving forward. Contact tracing has been an effective ways to control infections spread by close contact such as sexually transmitted diseases. In this article, we will explore the process and results of Contact tracing in relation to the current pandemic.
The Process
Contact tracing uses the process of identifying, assessing and managing those who have been exposed to a disease with the goal of preventing the spread of infection. This method has been incredibly effective for diseases such as sexually transmitted Infections, which are spread by close contact (Keeling et al, 2020).
For COVID-19, the process includes using surveys to report the number of social encounters. Normally people can identify those they've had reoccurring contact with, but a quick chat with a stranger is usually untraceable; however, there is always the difference between high and low risk encounters. High risk encounters include family members, or those you share a residence with, it makes a difference when you spend longer periods of time with people. Low risk encounters include consumers in a retail store or commuters on a train. You are more likely to become infected by a high risk encounter and they're usually easier to identify, while low risk encounters give less of a likelihood of infecting you, they're harder to identify.
Testing of social encounters is very important. Symptoms manifest at different times - early, late, and sometimes not at all - therefore accurate and comprehensive testing is crucial. Before "reopening" businesses and public spaces, it's important that government bodies take the time to assess their current public health care systems (Steinbrook, 2020).
They are now looking into app based contact tracing. A digital platform could be useful in identifying high risk cases and making an automatic process for the hard work authorities are doing now. However, there is a lot of concern surrounding data protection and it creates a complex argument. Is revealing location data worse than saving lives? (Abeler et al, 2020)
Results and Benefits
The COVID-19 Working Group at the Centre for the Mathematical Modelling of Infectious Diseases created a model to simulate the effectiveness of contact tracing. They found that contact tracing and case isolation worked well enough to contain a SARS-CoV-2 outbreak within 3 months. The combination with case isolation slows down the rate at which the virus can reproduce.
However, there were some limitations. Due to the nature of the virus, later symptoms led to delayed isolation. Which therefore caused more transmission before symptoms were identified (Hellewell, 2020).
When the best case scenario is a vaccine which will take 9-18 months to achieve, so-called "flattening the curve" of COVID-19 transmission is our best bet. The World Health Organization recommends; rapid diagnosis, immediately isolating cases, diligently tracking close contacts of identified cases, taking precautions by self isolating close contacts (Marcel et al., 2020).
It is beneficial to know about the different types of outbreak control, especially when we're in a pandemic. But it's important to remember that social distancing and limiting the people you see will reduce your risk of contracting the virus and protect others around you.
References:
Keeling, M. J., Hollingsworth, T. D., & Read, J. M. (2020). Efficacy of contact tracing for the
containment of the 2019 novel coronavirus (COVID-19). Journal of epidemiology and
community health, 74(10), 861–866. https://doi.org/10.1136/jech-2020-214051
Abeler, J., Bäcker, M., Buermeyer, U., & Zillessen, H. (2020). COVID-19 Contact Tracing and
Data Protection Can Go Together. Retrieved September 28, 2020, from https://mhealth.
Hellewell, J., Abbott, S., Gimma, A., Bosse, N., Jarvis, C., Russell, T., . . . Edmunds, W. (2020,
February 28). Feasibility of controlling COVID-19 outbreaks by isolation of cases and
contacts. Retrieved September 28, 2020, from https://www.sciencedirect.com/
Marcel, S., L., A. C., Richard, N., Silvia, S., Emma, H., & Jaques, F. (2020, March 19). COVID-19
epidemic in Switzerland: On the importance of testing, contact tracing and isolation [Pdf].
Swiss Medical Weekly.
Steinbrook, R. (2020, September 01). Contact Tracing, Testing, and Control of COVID-19-
Learning From Taiwan. Retrieved September 28, 2020, from https://jamanetwork.com/
Article Contributors: Mina Chong, Edie Whittington
Article Editor: Olivia Ye