Seroprevalence of SARS-CoV-2 among health care personnel in Portugal

Health care personnel (HCP) might be at high risk for contracting SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). This study aims to characterize the seroprevalence of SARS-CoV-2 among health professionals in Portugal. A cross-sectional study was conducted between June 1^st and July 19^th, 2020, following the first wave of COVID-19 in the country, with a convenience sample of HCP working in different Portuguese health units, both from the community and clinical settings, geographically distributed at the national level. HCP diagnosed with COVID-19 was an exclusion criterion of the study. Participants were tested for antibodies to SARS-CoV-2 with a chemiluminescence immunoassay that detect and quantify SARS-CoV-2 antibodies anti-IgG, and then asked about demographic characteristics, medical history, COVID-19 symptoms, previous clinical testing for acute SARS-CoV-2 infection, and Personal Protective Equipment (PPE) practices while caring for patients in areas with COVID-19 patients. A total of 1,802 HCP participated in the study, from all Regional Health Authorities of mainland Portugal, of which 81.0% were women. Almost half of the participants (48,1%) were nurses, and 29.6% were doctors. Among all participants, 55 (3.1%) had positive test results for SARS-CoV-2 antibodies and, from these, 28 (50.9%) did not reported to have had COVID-19 symptoms since the beginning of the year 2020. The majority of the HCP who had SARS-CoV-2 positivity indicated to always use PPE. Factors associated with infection, namely geographical distribution, profession, having had a family member with COVID-19 and having had contact with family members with COVID-19, as well as limitations to the study, will be discussed in further detail in this presentation. Understanding the prevalence of and factors associated with SARS-CoV-2 infection among HCP is important for protecting both HCP and their patients.