Investigation and Serologic Follow-Up of Contacts of an Early Confirmed Case-Patient with COVID-19, Washington, USA
Viruses, Respiratory Infections, serology, covid-19, SARS-CoV-2, contact-tracing
We describe the contact investigation for an early confirmed case of coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in the United States. Contacts of the case-patient were identified, actively monitored for symptoms, interviewed for a detailed exposure history, and tested for SARS-CoV-2 infection by real-time reverse transcription PCR (rRT-PCR) and ELISA. Fifty contacts were identified and 38 (76%) were interviewed, of whom 11 (29%) reported unprotected face-to-face interaction with the case-patient. Thirty-seven (74%) had respiratory specimens tested by rRT-PCR, and all tested negative. Twenty-three (46%) had ELISA performed on serum samples collected ≈6 weeks after exposure, and none had detectable antibodies to SARS-CoV-2. Among contacts who were tested, no secondary transmission was identified in this investigation, despite unprotected close interactions with the infectious case-patient.
Victoria T. Chu, Brandi Freeman-Ponder, 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, Holly M. Biggs
Centers for Disease Control and Prevention
Medicine, Infectious and parasitic diseases