Prevalence of IgG antibodies against SARS-CoV-2 among healthcare workers in a tertiary pediatric hospital in Poland

Abstract

Data on prevalence of SARS-CoV-2 antibody in healthcare workers (HCWs) is scare, especially in pediatric settings. The purpose of this study was to evaluate the SARS-CoV-2 IgG-positivity among HCWs of a tertiary pediatric hospital. In addition, follow-up of serological response in the subgroup of seropositive HCWs was performed, to get some insight on persistence of IgG antibodies to SARS-CoV-2. Free, voluntary SARS-CoV-2 IgG testing was made available to HCWs of the Children’s Memorial Health Institute in Warsaw (Poland). Plasma samples were collected between July 1 and August 9, 2020 and tested using the Abbott SARS-CoV-2 IgG assay. Of 2282 eligible participants, 1879 (82.3%) HCWs volunteered to undergo testing. Sixteen HCWs tested positive for SARS-CoV-2 IgG, corresponding to the seroprevalence of 0.85%. Among seropositive HCWs, three had confirmed COVID-19. Of note, 8 (50%) seropositive HCWs reported neither symptoms nor unprotected contact with confirmed SARS-CoV-2 cases in the previous months. A decline in the IgG index was observed at median time of 86.5 days (range:84-128 days) after symptom onset or RT-PCR testing. The nationwide public health response measures together with infection prevention and control practices implemented at the hospital level, at the beginning of the COVID-19 pandemic, might explain a low seroprevalence. Further studies are warranted to elucidate the duration of anti-SARS-CoV-2 antibodies, as well as the correlation between seropositivity and protective immunity against reinfection. Regardless of the persistence of antibodies and their protective properties, such low prevalence indicates that this population is vulnerable to a second wave of the COVID-19 pandemic.

Severe acute respiratory coronavirus virus 2 (SARS-CoV-2) seroprevalence among laboratory staff: Safe handling of coronavirus disease 2019 (COVID-19) samples

“…A large study on HCWs did not show any association between age or sex with positivity for SARS-CoV-2 IgG. 2 Interestingly, sex differences were observed in the perception of epidemic, with women being more emotionally affected and giving more attention to protective measures. 3 Many studies have evaluated SARS-CoV-2 seroprevalence in the general population and hospital HCWs, but to our knowledge, no studies have focused on laboratory staff.…”