Article Text
Abstract
Objectives Reverse transcriptase PCR (RT-PCR) is considered the gold standard in diagnosing COVID-19. Infected healthcare workers do not go back to work until RT-PCR has demonstrated that the virus is no longer present in the upper respiratory tract. The aim of this study is to determine the most efficient time to perform RT-PCR prior to healthcare workers’ reincorporation.
Materials and methods This is a cohort study of healthcare workers with RT-PCR-confirmed COVID-19. Data were collected using the medical charts of healthcare workers and completed with a telephone interview. Kaplan-Meier curves were used to determine the influence of several variables on the time to RT-PCR negativisation. The impact of the variables on survival was assessed using the Breslow test. A Cox regression model was developed including the associated variables.
Results 159 subjects with a positive RT-PCR out of 374 workers with suspected COVID-19 were included. The median time to negativisation was 25 days from symptom onset (IQR 20–35 days). Presence of IgG, dyspnoea, cough and throat pain were associated with significant longer time to negativisation. Cox logistic regression was used to adjust for confounding variables. Only dyspnoea and cough remained in the model as significant determinants of prolonged negativisation time. Adjusted HRs were 0.68 (0.48–096) for dyspnoea and 0.61 (0.42–0.88) for dry cough.
Conclusions RT-PCR during the first 3 weeks leads to a high percentage of positive results. In the presence of respiratory symptoms, negativisation took nearly 1 week more. Those who developed antibodies needed longer time to negativisate.
- virology
- risk assessment
- investigation of outbreaks of illness
- immunology
- hygiene / occupational hygiene
Data availability statement
Data are available upon reasonable request.
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- virology
- risk assessment
- investigation of outbreaks of illness
- immunology
- hygiene / occupational hygiene
Data availability statement
Data are available upon reasonable request.
Footnotes
Contributors JGM-M planned, coordinated, participated in data collection, performed statistical analysis of data, and wrote and submitted the manuscript. MCG, GDF, AEA, AFH, EGA, AHV, CIR, BMM and GVSM participated in data collection and study design. AMG and IC participated in study design, and in writing and correcting the manuscript. JJGL participated in the statistical analysis of data and in writing the manuscript.
Funding This work has received funding from Fundación para la Investigación e Innovación Biomédica del Hospital Universitario Infanta Sofía y Hospital Universitario del Henares.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.