key: cord-1030636-dtdab7r7
authors: Kojima, N.; Mores, C.; Farsai, N.; Klausner, J.D.
title: Duration of SARS-CoV-2 viral culture Positivity among different specimen types
date: 2021-07-16
journal: Clin Microbiol Infect
DOI: 10.1016/j.cmi.2021.07.004
sha: 2caa04482f8593a9340424975200dc6aa26d5ae9
doc_id: 1030636
cord_uid: dtdab7r7

nan

We read the article, Prolonged SARS-CoV-2 cell culture replication in respiratory 2 samples from patients with severe COVID-19, by Folgueira et al. that reported that 3 patients with severe COVID-19 might shed culturable virus with great interest [1] . 4

Current guidelines recommend persons with COVID-19 can discontinue isolation 5 without retesting 10 days after either symptom onset or a positive SARS-CoV-2 test 6 among asymptomatic persons [2] . That recommendation was made because prior 7 studies did not isolate SARS-CoV-2 from individuals beyond 9 days after symptoms 8 onset [3] . Additionally, positive viral culture has been rarely detected in clinical 9 specimens with a polymerase chain reaction (PCR) cycle threshold (Ct) value greater 10 than 34 cycles of amplification. With increasing use of oral fluid specimens for the 11 detection of SARS-CoV-2 [4], we sought to determine the performance of oral fluid 12 versus nasopharyngeal specimens for the duration and detection of culturable virus. We tested participants for SARS-CoV-2 with viral culture in an outpatient setting. We 50 found that culturable SARS-CoV-2 can be detected for most individuals up to 6 days 51 after symptom onset, however we detected SARS-CoV-2 by culture up to 14 days in a 52 few individuals from the time of symptom onset. We also found that SARS-CoV-2 could 53 be cultured in individuals with from oral mucosal fluid specimens, including specimens 54

with Ct values as high as 37.73 cycles. 55

Our study is not without limitations. Specimens were not sequenced in this study and 57 were assumed to be wild-type virus. It is possible higher Ct values were due to primer 58 mismatches from mutations in the virus. Negative controls remained negative and there 59 were no signs of cross-contamination. To reduce the risk of PCR inhibition, imperfect 60 controls, and improper culture interpretation, PCR specimens were run on different 61 plates with different batches of controls and cultures were verified with PCR testing. 62

SARS-CoV-2 cell culture replication in respiratory samples from patients with 93 severe COVID-19

World Health Organization. Criteria for releasing COVID-19 patients from 95 isolation

viral load dynamics, duration of viral shedding, and 99 infectiousness: a systematic review and meta-analysis

Swab Specimens for Detection of SARS-CoV-2

Self-Collected Oral Fluid and Nasal Swab 105

Nasopharyngeal Swab Specimens for the Detection of SARS-CoV-2

Variable Culture-positive (n=24) Culture-negative (n=4)