Characteristics and Timing of Initial Virus Shedding in Severe Acute Respiratory Syndrome Coronavirus 2, Utah, USA
Nathaniel M. Lewis, Lindsey M. Duca, Perrine Marcenac, Elizabeth A. Dietrich, Christopher J. Gregory, Victoria L. Fields, Michelle Banks, Jared R. Rispens, Aron J. Hall, Jennifer L. Harcourt, Azaibi Tamin, Sarah Willardson, Tair Kiphibane, Kimberly Christensen, Angela Dunn, Jacqueline E. Tate, Scott A. Nabity, Almea Matanock, Hannah L. Kirking
Abstract
T he coronavirus disease (COVID-19) outbreak first recognized in Wuhan, China, in December 2019 is now a global pandemic (1). Serial intervals for transmission have been estimated (2,3), and presymptomatic transmission from confirmed case-patients to others has been documented (4-8). In addition, studies suggest that virus shedding can begin before the onset of symptoms (7,8) and extend beyond the resolution of symptoms (9). However, data on the initiation and progression of viral shedding in relation to symptom onset and infectiousness are limited. Intensive early monitoring of household members through serial (i.e., daily) collection of a respiratory tract specimen for testing by real-time reverse transcription PCR (rRT-PCR), which could clarify the characteristics of initial viral shedding, has rarely been implemented, although serial self-collection of nasal and saliva samples was used in a recent study (10). To examine the transmission dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and guide public health recommendations, we describe initial detection and progression of SARS-CoV-2 viral shedding, as indicated by rRT-PCR positivity for SARS-CoV-2 and cycle threshold (C t ) values, in relation to exposure to an index patient, symptom onset and duration, and transmission to household contacts who underwent intensive early monitoring with viral cultures.