Cell-based Culture Informs Infectivity and Safe De-Isolation Assessments in Patients with Coronavirus Disease 2019.
Clin Infect Dis
; 73(9): e2952-e2959, 2021 11 02.
Article
in English
| MEDLINE | ID: covidwho-1501018
ABSTRACT
BACKGROUND:
The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA by reverse-transcription polymerase chain reaction (PCR) does not necessarily indicate shedding of infective virions. There are limited data on the correlation between the isolation of SARS-CoV-2, which likely indicates infectivity, and PCR.METHODS:
A total of 195 patients with Coronavirus disease 2019 were tested (outpatients, nâ =â 178; inpatients, nâ =â 12; and critically unwell patients admitted to the intensive care unit [ICU] patients, nâ =â 5). SARS-CoV-2 PCR-positive samples were cultured in Vero C1008 cells and inspected daily for cytopathic effect (CPE). SARS-CoV-2-induced CPE was confirmed by PCR of culture supernatant. Where no CPE was observed, PCR was performed on day 4 to confirm absence of virus replication. The cycle thresholds (Cts) of the day 4 PCR (Ctculture) and the PCR of the original clinical sample (Ctsample) were compared, and positive cultures were defined where Ctsample - Ctculture was ≥3.RESULTS:
Of 234 samples collected, 228 (97%) were from the upper respiratory tract. SARS-CoV-2 was isolated from 56 (24%), including in 28 of 181 (15%), 19 of 42 (45%), and 9 of 11 samples (82%) collected from outpatients, inpatients, and ICU patients, respectively. All 56 samples had Ctsample ≤32; CPE was observed in 46 (20%). The mean duration from symptom onset to culture positivity was 4.5 days (range, 0-18). SARS-CoV-2 was significantly more likely to be isolated from samples collected from inpatients (Pâ <â .001) and ICU patients (Pâ <â .0001) compared with outpatients, and in samples with lower Ctsample.CONCLUSIONS:
SARS-CoV-2 culture may be used as a surrogate marker for infectivity and inform de-isolation protocols.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
COVID-19
Type of study:
Diagnostic study
/
Prognostic study
Limits:
Animals
/
Humans
Language:
English
Journal:
Clin Infect Dis
Journal subject:
Communicable Diseases
Year:
2021
Document Type:
Article
Affiliation country:
Cid
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