contact tracing
noun
: the practice of identifying, notifying, and monitoring individuals who may have had close contact with a person having a confirmed or probable case of an infectious disease as a means of controlling the spread of infection
Health authorities in all these places are working hard to find the original source, or "patient zero," using what's called contact tracing, or finding all the people the patients were in contact with … . In a highly mobile world, that's increasingly difficult.—
The Salt Lake Tribune
The Salt Lake TribuneIn the previous two years, two chancroid cases had been diagnosed in Massachusetts. The outbreak was terminated by intensive surveillance efforts, contact tracing, and antimicrobial treatment of both symptomatic and asymptomatic sex partners.—The Journal of the American Medical Association
The Journal of the American Medical Association
contact tracer
noun
plural contact tracers
And each positive case will require a contact tracer to retrace the patient's steps and track down as many people as possible who they might have come into contact with.
—Luke DeCock and Adam Wagner
Luke DeCock and Adam Wagner
Examples of contact tracing in a Sentence
Recent Examples on the Web
Public health officials have started contact tracing efforts after more than 100 children were possibly exposed to measles at a Sacramento County event.
—Cecilio Padilla, CBS News, 6 Mar. 2026
But containing measles outbreaks also requires substantial investment in contact tracing, quarantines, and public-health messaging that might restrict people’s movements and behaviors—all of which could run up against Bhattacharya’s sensibilities.
—Katherine J. Wu, The Atlantic, 5 Mar. 2026
On top of the upfront cost, each additional case of measles averages $16,000 a pop for contact tracing, medical expenses and quarantine monitoring.
—Erika Edwards, NBC news, 1 Mar. 2026
Suffolk County Department of Health is also conducting contact tracing to see who should get tested.
—David Matthews, New York Daily News, 6 Feb. 2026
The health department said the child is in isolation and that contact tracing is underway but declined to provide additional information, citing privacy concerns.
—Mary Ramsey, Charlotte Observer, 27 Jan. 2026
Health techs do not require specialized degrees or certification like school nurses do but can still perform many of the same tasks, such as administering medications, managing sick students and helping with contact tracing.
—Kristen Taketa, San Diego Union-Tribune, 24 Mar. 2023
Faced with a dearth of data, workers deployed their own informal contact tracing, keeping an eye out for who was out that day, and calling and texting other employees to figure out which co-workers had been infected.
—Ambar Castillo, STAT, 1 Mar. 2023
Even the most rigorous implementations, which modified iOS or Android to provide new application programming interfaces specifically for contact tracing, seemed to fail exactly where they were needed most, on public transport.
—IEEE Spectrum, 6 Jan. 2021
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Cecilio Padilla, CBS News, 6 Mar. 2026
But containing measles outbreaks also requires substantial investment in contact tracing, quarantines, and public-health messaging that might restrict people’s movements and behaviors—all of which could run up against Bhattacharya’s sensibilities.
—Katherine J. Wu, The Atlantic, 5 Mar. 2026
On top of the upfront cost, each additional case of measles averages $16,000 a pop for contact tracing, medical expenses and quarantine monitoring.
—Erika Edwards, NBC news, 1 Mar. 2026
Suffolk County Department of Health is also conducting contact tracing to see who should get tested.
—David Matthews, New York Daily News, 6 Feb. 2026
The health department said the child is in isolation and that contact tracing is underway but declined to provide additional information, citing privacy concerns.
—Mary Ramsey, Charlotte Observer, 27 Jan. 2026
Health techs do not require specialized degrees or certification like school nurses do but can still perform many of the same tasks, such as administering medications, managing sick students and helping with contact tracing.
—Kristen Taketa, San Diego Union-Tribune, 24 Mar. 2023
Faced with a dearth of data, workers deployed their own informal contact tracing, keeping an eye out for who was out that day, and calling and texting other employees to figure out which co-workers had been infected.
—Ambar Castillo, STAT, 1 Mar. 2023
Even the most rigorous implementations, which modified iOS or Android to provide new application programming interfaces specifically for contact tracing, seemed to fail exactly where they were needed most, on public transport.
—IEEE Spectrum, 6 Jan. 2021
Cite this Entry
“Contact tracing.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/contact%20tracing. Accessed 10 Mar. 2026.
Copy CitationMedical Definition
contact tracing
noun
: the practice of identifying, notifying, and monitoring individuals who may have had close contact with a person having a confirmed or probable case of an infectious disease as a means of controlling the spread of infection
Public health modeling of the spread of COVID-19 has shown that successful contact tracing can reduce the number of infections dramatically, if infected individuals are quarantined, and their contacts and places visited can be identified.—Michela Franchini et al., International Journal of Environmental Research and Public Health
Michela Franchini et al., International Journal of Environmental Research and Public HealthIn the previous two years, two chancroid cases had been diagnosed in Massachusetts. The outbreak was terminated by intensive surveillance efforts, contact tracing, and antimicrobial treatment of both symptomatic and asymptomatic sex partners.—The Journal of the American Medical Association
The Journal of the American Medical Association
contact tracer
noun
The investigations are done by contact tracers who help identify close contacts of people who are COVID-19 positive, tell them how to quarantine and provide information about COVID-19.
—Terry DeMio, The Cincinnati (Ohio) Enquirer
Terry DeMio, The Cincinnati (Ohio) Enquirer
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