Evaluation of real-time PCR cycle threshold value, clinical and epidemiological characteristics of SARS-CoV-2 positive healthcare workers

ABSTRACT

INTRODUCTION: During the coronavirus infectious disease-2019 (COVID-19) pandemic, healthcare workers are the occupational group most affected by SARS-CoV-2. Infection of healthcare workers with SARS-CoV-2 poses a potential risk of infection for other healthcare workers, patients and their families. The viral load measure in the sample is determined as the cycle threshold (Ct) with the RT-qPCR method. It has been reported that the RT-qPCR Ct value may be related to the severity and potential contagiousness of the infection. In this study, it was aimed to evaluate the relationships between socio-demographic factors, COVID-19 symptoms and Ct value in SARS-CoV-2 RT-qPCR positive healthcare workers. METHODS: In this study, 300 healthcare workers with positive SARS-CoV-2 RT-qPCR test were included. SARS-CoV-2 RT-qPCR test was performed from nasopharyngeal and oropharyngeal swab samples with Bio-speedy SARS-CoV-2 RT-qPCR (Bioeksen, Turkey) kit. The RT-qPCR Ct value results of healthcare staff patients were classified as low, medium and high, socio-demographic characteristics and the risk of viral spread was evaluated. RESULTS: The rate of those who showed at least one symptom among the 300 health personnel included in the study was 88.3% (n=265) and the most common symptoms were muscle-joint pain 39.7%, fatigue 33% and sore throat 30.7%. The median RT-qPCR Ct value was determined as 23.17(19.3-29.4) and Ct value was found to be low (<24.0) in 59% of healthcare personnel. In addition, the Ct value of the personnel working in the administrative units was found to be lower than those working in the COVID-19 polyclinic, service and intensive care unit (p=0.020). Those who had fever and at least one of the COVID-19 symptom (fever, cough, respiratory distress) group had a lower Ct value than those who did not (p=0.008, p=0.019, respectively). When the possible source of transmission was evaluated, it was determined that 22% of the health personnel were infected during patient care, 21% from other health personnel and 23.3% from non-hospital sources. DISCUSSION AND CONCLUSION: Our results have shown that most of the SARS-CoV-2 transmission seen in healthcare workers occurs within the hospital, but more viral load is exposed in out-of-hospital contacts. In addition, it has been observed that administrative personnel who do not have contact with patients can be a potential source of transmission. This situation has reaffirmed that PPE usage rules should be followed in order to reduce the risk of transmission in healthcare personnel and that personnel working outside the clinic should follow the mask and distance rules during their contact with their colleagues. It was determined that the Ct value was lower (higher viral load) in the presence of any of the symptoms of fever, cough, respiratory distress and fatigue in healthcare workers. In the presence of these symptoms, PCR testing of healthcare workers and taking necessary isolation measures until the test result is obtained will reduce the possibility of transmission.