Department of Hygiene and Epidemiology, University of Ioannina Faculty of Medicine, 45110 Ioannina, Greece
Vassiliki Papaevangelou
Third Department of Paediatrics, School of Medicine, Attikon University Hospital, National and Kapodistrian University of Athens, 12462 Athens, Greece
Achilleas Gikas
Internal Medicine Department, Infectious Diseases Unit, University Hospital of Heraklion, School of Medicine, University of Crete, 71500 Heraklion, Greece
Alkiviadis Vatopoulos
Department of Public Health Policy, School of Public Health, University of West Attica, 11521 Athens, Greece
Evangelia E. Ntzani
Department of Hygiene and Epidemiology, University of Ioannina Faculty of Medicine, 45110 Ioannina, Greece
Panagiotis Prezerakos
Department of Nursing, University of Peloponnese, 22100 Tripoli, Greece
Sotirios Tsiodras
Fourth Department of Internal Medicine, School of Medicine, Attikon University Hospital, National and Kapodistrian University of Athens, 12462 Athens, Greece
Christos Hadjichristodoulou
Laboratory of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, 41222 Larissa, Greece
A serosurvey of IgG antibodies against SARS-CoV-2 was conducted in Greece between May and August 2020. It was designed as a cross-sectional survey and was repeated at monthly intervals. The leftover sampling methodology was used and a geographically stratified sampling plan was applied. Of 20,110 serum samples collected, 89 (0.44%) were found to be positive for anti-SARS-CoV-2 antibodies, with higher seroprevalence (0.35%) observed in May 2020. The highest seroprevalence was primarily observed in the “30–49” year age group. Females presented higher seroprevalence compared to males in May 2020 (females: 0.58% VS males: 0.10%). This difference reversed during the study period and males presented a higher proportion in August 2020 (females: 0.12% VS males: 0.58%). Differences in the rate of seropositivity between urban areas and the rest of the country were also observed during the study period. The four-month infection fatality rate (IFR) was estimated to be 0.47%, while the respective case fatality rate (CFR) was at 1.89%. Our findings confirm low seroprevalence of COVID-19 in Greece during the study period. The young adults are presented as the most affected age group. The loss of the cumulative effect of seropositivity in a proportion of previous SARS-CoV-2 infections was indicated.
