ABSTRACT
On December 30, 2019, the city of Wuhan, China, experienced an outbreak of unexplained pneumonia. From January 7, 2020, a new betacoronavirus, severe acute respiratory syndrome coronavirus was identified (SARS-CoV-2). The World Health Organization (WHO) has since declared a pandemic with millions of confirmed cases worldwide. As part of the fight against the epidemic, laboratories have a critical role in assessing the reliability of new serological assays before taking part of diagnostic protocols or made available broader to the community and to evaluate commutability between assays. The aim of this study was to perform a comparison between two automated assays for SARS-CoV-2 IgG testing, the MAGLUMI ® 800 and the LIAISON ® XL. Among the patients confirmed positive for COVID-19, the two automated assays were significantly correlated (r = 0.811; p < 0.0001). The overall concordance made for MAGLUMI 2019-nCoV IgG positive/negative vs. LIAISON® SARS-CoV-2 IgG positive/negative results was 79% (Index Kappa of Cohen). We list the discrepancies between the two analyzers among the 44 tested patients. In conclusion, the overall agreement between the two automated assays for SARS-CoV-2 was good. However, the MAGLUMI assay might be more sensitive at the early stages of antibody development and there is a lack of specificity with LIAISON XL.
ABSTRACT
BACKGROUND: Healthcare workers (HCWs) are at high risk of acquiring COVID-19 and could play a role in nosocomial transmission. Since 4th February 2020, Belgian Health authorities reported more than 90,568 cases, of which 8.3% were HCWs. Data on clinical characteristics, sources of infection and humoral immune response of HCWs with COVID-19 remain scarce. AIM: To analyse the clinical characteristics, humoral immune response, sources of contamination, and outcomes among HCWs with COVID-19. METHODS: This retrospective study included 176 HCWs with laboratory-confirmed COVID-19 in a teaching hospital in Belgium. Between 1st March and 31st May 2020, all HCWs with symptoms suspected of COVID-19 were tested by reverse transcription polymerase chain reaction on a nasopharyngeal swab. Serological testing was performed between 55 and 137 days after the onset of symptoms. FINDINGS: Median age was 40.8 years and 75% were female. Median delay between onset of symptoms and diagnosis was 4.39 days. Most frequent symptoms were cough and headache (both 75%). Fever accounted for 68.7%. Most represented professions were nurses (42%). HCWs were mainly infected by patient contact (32.9%); 7.6% required hospitalization and 1.7% were admitted to the intensive care unit. Unfortunately, one HCW died (0.5%). Total antibodies were positive in 109/126 (86.5%). CONCLUSIONS: Clinical presentation of COVID-19 in HCWs does not differ from the general population. However, outcomes were more favourable with a mortality rate lower than that reported in Belgian COVID-19 patients in general (16%). The main source of infection was the hospital setting. Our positive antibodies rate was high but lower than previously reported.