Evaluation of cycle threshold to assist with safe return to work for healthcare workers with coronavirus disease 2019 (COVID-19)

• Published in: Infection control and hospital epidemiology Vol. 44; no. 4; pp. 681 - 682
• Main Authors: Selby, Laura M., Hewlett, Angela, Wood, Macy G., Starlin, Richard
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 01-04-2023
• Subjects: Asymptomatic; Coronaviruses; COVID-19; COVID-19 vaccines; Disease transmission; Employees; Health care; Health Personnel; Humans; Influenza; Labor shortages; Literature reviews; Medical personnel; Nosocomial infection; Occupational health; Outbreaks; Pandemics; Research Brief; Return to Work; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Workforce planning
• ISSN: 0899-823X; 1559-6834
• DOI: 10.1017/ice.2022.252

The coronavirus disease 2019 (COVID-19) pandemic has resulted in critical staffing shortages in healthcare facilities due to many ill healthcare workers (HCWs), and this has been particularly evident with the emergence of the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) ο (omicron) variant in late 2021.1,2 In response to an escalating critical staffing deficiency, the University of Nebraska Medical Center instituted a return-to-work testing program through the employee health department to evaluate cycle threshold (Ct) values in HCWs in critical hospital roles. The detection of COVID-19 via RT-PCR does not necessarily equate to infectiousness; patients can have positive PCR tests in the absence of culturable virus.3 Although currently available SARS-CoV-2 RT-PCR testing is not a true quantitative measure, published literature has demonstrated that SARS-CoV-2 can most consistently be grown in viral culture when the Ct is <30.3–6 Other studies have shown that it is possible to culture viable virus in patients with Ct values in the 30–35 range; however, the yield is low.4 Starting on January 1, 2022, HCWs with mild or asymptomatic COVID-19 with resolving symptoms were tested with RT-PCR via nasopharyngeal swab 5–7 days after symptom onset or initial positive SARS-CoV-2 test, whichever was earlier. Numerous nosocomial outbreaks of COVID-19 have been reported since the start of the pandemic.7,8 A systematic literature review of 35 hospital outbreaks revealed that 40% of the primary cases were HCWs.7 Based on this, identifying HCWs who remain potentially infectious could decrease the risk of nosocomial COVID-19 cases in coworkers, patients, visitors, and others in the healthcare environment.