Persistence of live virus in critically ill patients infected with SARS-COV-2: a prospective observational study

Critical Care

Jared Bullard¹  Lauren Garnett²  Anand Kumar³  Gloria Vazquez Grande³  Sylvan Lother³  Guillaume Poliquin⁴  Jim Strong⁴  Duane J. Funk⁵  Kerry Dust⁶  Kaylie Doan⁶ 

[1] Cadham Provincial Laboratory, Manitoba Health, Winnipeg, MB, Canada;Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB, Canada;Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada;Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada;National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada;Department of Medicine, Sections of Infectious Disease and Critical Care, University of Manitoba, Winnipeg, MB, Canada;Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB, Canada;Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada;National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada;Departments of Anesthesiology and Medicine, Section of Critical Care, Max Rady College of Medicine, University of Manitoba, 2nd Floor Harry Medovy House, 671 William Avenue, R3E 0Z2, Winnipeg, MB, Canada;National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada;National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada;

关键词: COVID-19;    Viral culture;    RT-PCR;    Infection control;   

DOI  :  10.1186/s13054-021-03884-z

来源: Springer

【 摘 要 】

BackgroundResearch on the duration of infectivity of ICU patients with COVID-19 has been sparse. Tests based on Reverse Transcriptase polymerase chain reaction (RT-PCR) detect both live virus and non-infectious viral RNA. We aimed to determine the duration of infectiousness based on viral culture of nasopharyngeal samples of patients with COVID-19.MethodsProspective observational study in adult intensive care units with a diagnosis of COVID-19 Pneumonia. Patients had repeated nasopharyngeal sampling performed after day 10 of ICU admission. Culture positive rate (based on viral culture on Vero cells in a level 4 lab) and Cycle threshold from RT-PCR were measured.ResultsNine patients of the 108 samples (8.3%, 95% CI 3.9–15.2%) grew live virus at a median of 13 days (interquartile range 11–19) after their initial positive test. 74.1% of patients were RT-PCR positive but culture negative, and the remaining (17.6%) were RT-PCR and culture negative. Cycle threshold showed excellent ability to predict the presence of live virus, with a Ct < 25 with an AUC of 0.90 (95% CI 0.83–0.97, p < 0.001). The specificity of a Ct > 25 to predict negative viral culture was 100% (95% CI 70–100%).Conclusion8.3% of our ICU patients with COVID-19 grew live virus at a median of 13 days post-initial positive RT-PCR test. Severity of illness, use of mechanical ventilation, and time between tests did not predict the presence of live virus. Cycle threshold of > 25 had the best ability to determine the lack of live virus in these patents.

【 授权许可】

CC BY