ABSTRACT
Objectives: This research aimed to study the seroconversion among frontline staff at the highest risk of exposure to SARS-CoV-2 infections, including emergency department, critical care, and COVID-19 isolation wards in all healthcare job categories. Methods: We conducted a prospective cohort study on the incidence of seroconversion among frontline health care workers (HCWs) at the Royal Hospital, Muscat, Oman. Two sera were collected 12 weeks apart to look for seroconversion. We used proportions with 95% confidence interval (CI) for categorical data and mean/median as appropriate for continuous data. Results: Fourteen out of 328 HCWs seroconverted in this study accounting for an incidence rate of 3.6%, excluding four HCWs that were positive at baseline. The median age was 43.5 (range = 28-57). About 75.0% of HCWs were between 31-49 years old, with a seroconversion rate of 4.9% (95% CI: 2.7-8.1). Females accounted for most seroconverted HCWs (14/257) at a rate of 5.4% (95% CI: 3.1-8.8). Omanis seroconverted with a rate of 6.4% (95% CI 2.6-12.8), whereas non-Omanis seroconverted at a rate 4.3% (95% CI: 2.2-7.5). Ninety-two percent (302/328) of the staff lived in the capital area, and a minority lived outside the capital (3/26). Thirteen Muscat citizens seroconverted at a rate of 4.3% (95% CI: 2.4-7.1). Nurses comprised the majority (accounting for about 81%) followed by doctors (19%) at rates of 5.6% (95% CI: 3.2-9.2) and 4.2% (95% CI: 1.07-10.9), respectively. Staff covering COVID-19 isolation wards and intensive care unit comprised over 60% (n = 10) of those who seroconverted with a rate of 5.4% (95% CI: 2.8-9.5) followed by infectious diseases doctors and adult emergency at 19.0% (n = 3) and 12.5% (n = 1), respectively. Approximately 81.3% (n = 13) of HCWs performed aerosol-generating procedures at a seroconversion rate of 4.3% (95% CI: 2.4-7.1). About 50.0% of those who seroconverted had a positive polymerase chain reaction (PCR) before seroconversion, 25.0% had a negative PCR before second serology testing, and 25.0% were not tested with PCR. Approximately 20.0% of seroconverted staff had no reported symptoms compared to 80.0% who reported symptoms such as sore throat (70.0%), fever (50.0%), myalgia (20.0%), and a less frequency (15.0%) runny nose, loss of smell, and headache. Conclusions: Detection of infection among HCWs is important to prevent further transmission, especially asymptomatic carriers. A combined screening strategy of symptoms, serology, and PCR might help detect potential infections and asymptomatic carriage.
ABSTRACT
INTRODUCTION: Coronavirus disease 2019 (COVID-19) is a new emerging infectious disease, first identified in China in December 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study describes the characteristics of healthcare workers (HCWs) who tested positive for COVID-19 in a tertiary care hospital in Oman. METHODS: This was a cross-sectional descriptive analysis of HCWs with COVID-19. RESULTS: During the study period, 204 HCWs tested positive for COVID-19 by rRT-PCR test, with a test positivity rate of 21.2%; the percentage of infected hospital staff was 4.3%. Their mean age was 36 years. Overall, 2.2% of the male staff were infected, while 9.3% of the female staff were infected. Among the clinicians, 4.7% were infected; among the nurses, 4.1% were infected. Regarding acquisition, 61.3% of infections (n = 125) were community-acquired and 25.5% (n = 52) were hospital-acquired; no source was identified in 13.2% of cases (n = 27). There was a significant difference between hospital-acquired and community-acquired COVID-19 according to the different HCW categories (p < 0.001), sex (p = 0.041), and being at risk of COVID-19 exposure in the hospital (p < 0.001). There were no significant differences in relation to nationality (p = 0498), age (p = 0.119), or the presence of co-morbidities (p = 0.326). Seventy-eight percent (n = 160) had no chronic diseases and 44% presented with fever and an acute respiratory infection (n = 90); all made an uneventful full recovery. The peak of infection acquisition was after the Eid Al Fitr festival. CONCLUSIONS: HCWs are at an increased risk of COVID-19 in the workplace. The strengthening of infection control measures to prevent exposures from infected patients and colleagues and to reduce the spread of COVID-19 is a necessity.