University of Sourthern California


What You Need to Know About Contact Tracing

Contract tracing on a cell phoneContact tracing is a critical method for preventing the spread of COVID-19. It helps public health officials better understand localized outbreaks and their origins while also providing lessons in where and how people can transmit the virus or become infected.

While contact tracing seems simple in concept – alert persons who may have been exposed to a transmissible illness – it is quite complex in its execution. Beyond the logistics of launching and running a contact tracing operation, there are variables in human behavior that can decide the success (or failure) of such efforts.

The History of Contact Tracing

Anecdotal reports of contact tracing go back to the Middle Ages and early attempts to lessen the spread of illnesses like syphilis and the bubonic plague. However, the practice was not formalized until the mid-19th century.

The New England Journal of Medicine (NEJM) provides a historical perspective on the advent of contact tracing in the United Kingdom, while bacteriology was still a new science. Contract tracers needed to have knowledge of physics, chemistry, statistics, public health and hygiene. But, the most important skill, the ability to persuade others to get vaccinated and stay quarantined, had to be learned by doing.

Tracers, or inspectors as they were called, were first mobilized in the United Kingdom in the fight against smallpox. Over the years, the United States followed suit and created its own surveillance system for infectious diseases including tuberculosis, scarlet fever and bacterial meningitis. This system has evolved in sophistication and continues to be used for HIV, SARS, Ebola and now, COVID-19.

Tuberculosis as a Study in Contact Tracing

Tuberculosis (TB) is used as an example by the Centers for Disease Control and Prevention (CDC) to help educate contact tracers on the basics of the investigation process. Contract tracers learn how to identify people who have been exposed to TB, assess those persons for infection, and provide treatment resources. The goals are threefold: interrupt the spread, prevent outbreaks, and ensure appropriate medical care.

Tuberculosis, like COVID-19, is transmitted through the air. Also, in similarity to COVID-19, not everyone exposed to TB will become infected, or if infected, show signs of the disease. That’s because TB can also manifest as latent TB infection (LTBI) in which the bacteria remain under control within the immune system. In another commonality with COVID-19, preexisting health conditions increase the risk of developing TB.

Contract tracing protocols are enacted upon a suspected case of illness, following a systematic 10-step approach. The onus is on state and local health departments to not only investigate cases but evaluate the effectiveness of those investigations. Occupational health investigations may also take place at the workplace of an infected employee. 

Contract Tracing Challenges with COVID-19

There is a large degree of public mistrust surrounding COVID-19, along with heightened emotions of fear and anxiety. The lack of consistent responses across the nation, and around the globe, have only increased confusion and made it harder to manage the spread of the virus. The challenges facing health departments and contract tracers are daunting.

Lack of Resources

A piece in National Geographic provides an overview of the practical challenges facing contract tracing efforts in the United States. Money is at the crux at the issue, as state and local budgets have been cut and tax revenues decline with the economic downturn. In June 2020, the CDC advised that the country would need 100,000 contract tracers. Other groups put that estimate, and the billions it would cost, even higher.

Even if a community has the funds to launch a contract tracing operation, it is faced with obstacles in hiring and training contract tracers, getting test results in a timely manner, and ensuring that individuals have what they need to quarantine safely. Tactful communication is key to success and can only be effective when coupled with empathy and patience.

Compliance Avoidance

Another central challenge is in ensuring compliance from those who are identified as contacts of an infected person. The CDC advises that if an individual gets a call from the health department, they should answer it and cooperate under the guarantee of confidentiality.

Of course, as with every crisis, there are scammers trying to take advantage of the situation. A legitimate contact tracer will never ask for a social security number, banking or salary information, or credit card number. Nor will they ever share the actual name of the infected or exposed individual with the others they have been in contact with. All information is kept private.

Myths and Misinformation

There are several myths surrounding contact tracing and this makes compliance even harder to achieve. To help combat disinformation, the group Partners in Health (PIH) has created a page to communicate “Fact vs. Fiction.”

Common myths surround the ineffectiveness of contract tracing and the belief that individuals will be forced to download a tracking app on their phones. While mobile apps have been announced by big tech firms, adoption rates are low as there is no mandate for citizens to use them.

There is also a worry that people can be forced from their homes if they have been exposed to COVID-19. Contract tracers will provide help to avoid such scenarios by connecting individuals and families with community resources for housing and other support services that may be needed during quarantine.

Unique concerns have also emerged among the immigrant community. Some undocumented immigrants believe they will be deported and/or that they shouldn’t answer the phone if they don’t speak English well. No personal details will ever be shared with immigration or other federal agencies. In addition, contract tracers will either be multilingual or have translators available to help serve vulnerable communities. 

Public Health and Looking Ahead

An article in Nature loosely projects the future of COVID-19, based on a compendium of unknowns. What all scenarios agree upon, however, is that the virus is here to stay.

The pandemic is manifesting in different ways in different places, as lockdowns are eased or tightened back up again. Personal behavioral changes in terms of handwashing and mask-wearing are inconsistent, as contract tracing efforts. Some researchers suggest that the virus will have annual surges and be with us through 2025 and beyond.

All of which gives healthcare professionals and policy leaders opportunities to create change and deploy better systems and ideas. If you aspire to a career in public health, global health, epidemiology, public health policy or any of the related disciplines, an online MPH degree can help you prepare.



CDC & Tuberculosis

National Geographic