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Volume 26, Number 8—August 2020

Investigation and Serologic Follow-Up of Contacts of an Early Confirmed Case-Patient with COVID-19, Washington, USA

Victoria T. Chu1Comments to Author , Brandi Freeman-Ponder1, Scott Lindquist, Christopher Spitters, Vance Kawakami, Jonathan W. Dyal, Shauna Clark, Hollianne Bruce, Jeffrey S. Duchin, Chas DeBolt, Sara Podczervinski, Marisa D’Angeli, Kristen Pettrone, Rachael Zacks, Grace Vahey, Michelle L. Holshue, Misty Lang, Rachel M. Burke, Melissa A. Rolfes, Mariel Marlow, Claire M. Midgley, Xiaoyan Lu, Stephen Lindstrom, Aron J. Hall, Alicia M. Fry, Natalie J. Thornburg, Susan I. Gerber, Satish K. Pillai, and Holly M. Biggs
Author affiliations: Centers for Disease Control and Prevention, Atlanta, Georgia, USA (V.T. Chu, B. Freeman-Ponder, J.W. Dyal, Kristen Pettrone, R. Zacks, G. Vahey, M.L. Holshue, R.M. Burke, M.A. Rolfes, M. Marlow, C.M. Midgley, X. Lu, S. Lindstrom, A.J. Hall, A.M. Fry, N.J. Thornburg, S.I. Gerber, S.K. Pillai, H.M. Biggs); Washington State Department of Public Health, Shoreline, Washington, USA (S. Lindquist, C. DeBolt, S. Podczervinski, M. D’Angeli, M.L. Holshue, M. Lang); Snohomish Health District, Everett, Washington, USA (C. Spitters, H. Bruce); Public Health—Seattle and King County, Seattle, Washington (V. Kawakami, S. Clark, J.S. Duchin); University of Washington, Seattle (J.S. Duchin)

Main Article

Table 1

Contact definitions, number of contacts identified by category, and comments regarding the contact identification process during the contact investigation of an early confirmed US COVID-19 case, Washington, USA, 2020*

Community contact
Any close contact (being within 6 feet of the case-patient) for a prolonged time (>10 min), other than office co-worker 0 None
Being an office co-worker of the case-patient with close contact of any duration 11 office co-workers None
Contact with infectious secretions from the case-patient 0 None
Sharing a healthcare waiting room or area during the same time and up to 2 h after the case-patient was present
31 waiting room patients
7/31 of the waiting room contacts likely overlapped with the case-patient in the waiting room.
Healthcare contact Any face-to-face interactions between an HCP and the case-patient without the HCP wearing full PPE† 6 HCP None
Potential contact with the case-patient’s infectious secretions by an HCP without wearing full PPE‡ 2 HCP 2 HCP were EVS workers who did not have direct contact with the case-patient. They were included for potential exposure to infectious secretions from the case-patient while cleaning surfaces.

*COVID-19, coronavirus disease; EVS, environmental services; HCP, healthcare personnel; PPE, personal protective equipment.
†Contact definitions were developed on January 21, 2020, before published guidance from CDC for COVID-19 was available. Contacts were identified during the time from the case-patient’s symptom onset until the case-patient was appropriately isolated. An airport shuttle driver who had contact with the case-patient before symptom onset was identified during contact tracing but was not included in this investigation. He self-monitored for 14 days and reported remaining asymptomatic.
‡At the time of the investigation, full PPE consisted of gown, gloves, eye protection, and an N95 respirator.

Main Article

1These authors contributed equally to this article.

Page created: May 12, 2020
Page updated: July 17, 2020
Page reviewed: July 17, 2020
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