ABSTRACT
OBJECTIVES: This study aimed to analyze the characteristics of coronavirus disease 2019 (COVID-19) infected health care workers (HCWs) and to measure their immunoglobulin G (IgG) response. METHODS: This is a retrospective and prospective cohort study where details of COVID-19 infected HCWs were collected in a pre-designed database in Al-Nahdha Hospital between 2 April and 24 July 2020. A single serum sample was collected from participating HCWs to detect the presence of IgG in their sera. RESULTS: Out of 974 HCWs, 103 (10.6%) were infected and tested positive for severe acute respiratory syndrome coronavirus 2 by real-time reverse transcriptase polymerase chain reaction. Nurses and doctors were the most affected groups. The source of infection was the hospital in 50.0% of cases. Nurses were more than four times likely to have a hospital-acquired COVID-19 infection (odds ratio = 4.63, 95% confidence interval: 1.71-12.52, p-value = 0.002). HCWs working in COVID-19 areas were more likely to have hospital-acquired infection than community-acquired infection (p < 0.005). All infected HCWs made a full recovery, with only 3.9% requiring admission. Out of 74 tested HCWs for IgG, 60 (81.1%) were positive. IgG positivity rate was significantly higher among HCWs in COVID-19 areas (p =0.026) and among non-Omanis (p =0.008). Moreover, the median IgG level was significantly higher among non-Omanis (p =0.004). CONCLUSIONS: This study has highlighted the group at higher risk of hospital-acquired COVID-19 infection which was nurses and those working in COVID-19 areas. It highlighted as well the high seropositivity among this infected group. These findings support the national guidelines on priority groups for vaccination among HCWs working in COVID-19 areas with no previous laboratory-confirmed COVID-19.
ABSTRACT
In response to the current COVID-19 pandemic, numerous commercial assays have been developed for the detection of SARS-CoV-2 for use in the clinical diagnostic laboratories. To date, there is limited comparison of testing methods performed in different hospital laboratory sites. The aims of the study were to evaluate the analytical performance of Cepheid Xpert Xpress SARS-CoV-2 when compared to RT-PCR. This is a cross-sectional study. A total of 155 nasopharyngeal swabs were taken in duplicate from patients presenting with suspected COVID-19 to 8 hospitals in Oman. One swab was tested by the hospital laboratory and the duplicate swab was sent to the national Central Public Health Laboratory (CPHL) for testing. We compared the analytical performance of the commercially available point of care Cepheid Xpert Xpress SARS-CoV-2 assay which was used in the 8 different hospitals with assays including Liferiver, Sansure, TIB MOL BIOL, Kingfisher and COBAS 6800 by Roche which were performed at the CPHL. Testing of the duplicate swabs revealed excellent agreement of results with the viral loads of Ct values ranging from 16-43 for the E gene, 18-44 for the N gene and 17-44 for the ORF gene using the Liferiver assay. The overall sample sensitivity and specificity of the Cepheid Xpert Xpress SARS-CoV-2 assay were both 100% and there was 100% agreement across specimens. We conclude that the rapid GeneXpert and RT-PCR kits assessed in this study may be used for routine diagnostic testing of COVID-19 patients by experienced clinical microbiology diagnostic laboratories. Our results highlight the importance of rapid molecular testing at different sites within a country in a public health emergency.