How an Army of Contact Tracers Will Help Contain COVID-19

Learn what contact tracing is and how it will help officials monitor and control the pandemic.

crowd with graphic depiction of exposure

Medically reviewed in April 2022

Updated on May 15, 2020

As the psychological and financial toll of COVID-19 lockdown weighs heavily on communities across the United States, a decades-old disease control strategy is one of the keys to curbing the pandemic, re-opening local economies and getting Americans back to work: contact tracing.

Health experts insist this painstaking process of tracking and containing outbreaks has a vital role to play in easing social distancing orders, while preventing a resurgence of the disease.

But what’s involved in contact tracing and how does it help?

How ‘disease detectives’ operate
Contact tracing is a technique that involves the careful questioning of a person diagnosed with an infectious disease and tirelessly tracking down anyone they had contact with—family, housemates, friends, co-workers, healthcare providers—up to 48 hours before they developed symptoms.

These known “contacts” must then self-isolate from other people for 14 days, starting from the day they were exposed to the infection. The idea is that immediately identifying and isolating the people who may have been exposed to a contagious germ could help prevent them from passing it on to others.

Once these contacts are traced, health officials can warn them about their potential exposure, educate them about the risks involved and teach them how to monitor themselves and protect others from the infection. Tracers also follow up with the contacts they identify to determine if they develop symptoms of the infection.   

It’s worked in the past
Contact tracing has long been effective in controlling outbreaks of highly contagious diseases, including tuberculosis. Contact tracing also played an important role in controlling smallpox, which was declared eradicated by the World Health Organization in 1980. More recently, health officials have utilized this strategy to respond to sexually transmitted diseases, measles, whooping cough and chicken pox. Contact tracing also helped control SARS in 2003 and the 2014 Ebola virus outbreak.  

Now, scientists will employ the technique once again in the battle against COVID-19.

Contact tracing is “something that health departments do all the time,” says Christopher Ohl, MD, an infectious diseases specialist at Wake Forest Baptist Health in Winston-Salem, North Carolina. “They just haven’t had to do it on this scale before.”

States are building contact tracing ‘armies’
The process of contact tracing is labor-intensive, and the Centers for Disease Control and Prevention (CDC) cautions that “large cadres” of contact tracers will be required to control the spread of COVID-19 in the United States. The Johns Hopkins Center for Health Security estimates that some 100,000 full-time tracers will be needed for at least one year at a cost of $3.6 billion.

New York Governor Andrew Cuomo has partnered with former New York Mayor Mike Bloomberg to launch a new COVID-19 contact tracing program in his state as well as New Jersey and Connecticut.

For the program, the Johns Hopkins Bloomberg School of Public Health established an online training curriculum for contact tracers. The New York State Department of Health is also working with Bloomberg Philanthropies to help identify and recruit contact tracers for the program. An expert panel will also evaluate the effectiveness of the online training course, aiming to create a model that can be duplicated and implemented in other states.

New York is looking to hire as many as 17,000 contact tracers. "If we don't start the contact tracing work, we have to shelter in place for longer periods. And I think that's something that most people are not wanting to do, obviously," Kelly Henning, MD, an epidemiologist who leads Bloomberg Philanthropies' public health program, told NPR.

Other states have followed suit. Massachusetts announced plans to employ 1,000 people in a virtual call center. Georgia will rely on hundreds of state employees and volunteers for its own contact tracing program. California is also building a 10,000-strong tracer group.

Federal efforts to support state contact tracing programs are also underway. The CDC and the Federal Emergency Management Agency (FEMA) have deployed tracers to assist Vermont’s tiny team of 30 contact tracers, while the National Guard is assisting Rhode Island.

Opportunities for the unemployed
From March to early May 2020, more than 36.5 million Americans filed jobless claims as businesses struggling during lockdown restrictions were forced to lay off or furlough employees. These workers may find new opportunities as contact tracers.

Some lawmakers are proposing a national-works program that would train and deploy unemployed people nationwide as contact tracers.  

Contact tracers do not need a medical degree or previous medical experience. They need a high school diploma or the equivalent. They also need to understand the medical issues involved and the need for diligence in tracking people down and respecting patient confidentiality. Contact tracers must understand and be sensitive to the culture of the communities they serve and build trust with others during lengthy and potentially sensitive interviews. They also offer basic counseling and help refer people to resources within their communities.

The new online class developed by the Johns Hopkins Bloomberg School of Public Health is now available to train contact tracers. The six-hour course is free and open to anyone. Within hours of the release of the class on May 11, more than 400 people had already registered, the Bloomberg School reports.

The class, called "COVID-19 Contact Tracing," teaches the basics of interviewing people who’ve been diagnosed with COVID-19, identifying their close contacts who could have been exposed to the coronavirus that causes the disease and providing them with instructions on how to safely self-quarantine for two weeks.

Those interested in becoming a contact tracer can contact their local health department for more information. The nonpartisan organization, Contrace Public Health Corps, is also helping states create and expand their COVID-19 contact tracing teams.

It’s not a panacea
The efforts of contact tracers to identify the people who’ve been exposed to someone with COVID-19 and inform them about the need for self-quarantine are only effective if these known “contacts” comply, Dr. Ohl notes.

“When you’re told, ‘Hey, you’re a contact—you need to quarantine,’ you need to do it for the good of the community,” he explains. “People have to be really good citizens and follow through. Otherwise we’re never going to get out of this until there’s a vaccine.”

Article sources open article sources

M Begun, AT Newall, GB Marks, JG Wood. “Contact tracing of tuberculosis: a systematic review of transmission modelling studies.” PLoS One. Sept 4 2013;8(9):e72470.
Martin Eichner. “Case Isolation and Contact Tracing Can Prevent the Spread of Smallpox.” American Journal of Epidemiology. Volume 158, Issue 2, 15 July 2003, Pages 118–128.
World Health Organization. “Smallpox.”
Centers for Disease Control and Prevention. “Coronavirus Disease 2019 (COVID-19): Contact Tracing.”
Center For Health Security. “A National Plan to Enable Comprehensive COVID-19 Case Finding and Contact Tracing in the US.” “Amid Ongoing COVID-19 Pandemic, Governor Cuomo and Mayor Mike Bloomberg Launch Nation-Leading COVID-19 Contact Tracing Program to Control Infection Rate.”
Johns Hopkins University. “Johns Hopkins launches online course to train army of contact tracers to slow spread of COVID-19.”
NPR. “Wanted In New York: Thousands Of COVID-19 Contact Tracers.”
Centers for Disease Control and Prevention. “Coronavirus Disease 2019 (COVID-19): Contact Tracing: Part of a Multipronged Approach to Fight the COVID-19 Pandemic.” “Working to identify & screen an army of 50,000 contact tracers to help fight COVID-19 & safely reopen the US economy.”

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