SARS-CoV-2 seroprevalence trends in healthy blood donors during the COVID-19 Milan outbreak

Objectives: The Milan metropolitan area in Northern Italy was among the most severely hit by the SARS-CoV-2 outbreak. The epidemiological trends of mild COVID-19 are however still unknown. The aim of this study was to examine the seroprevalence of SARS-CoV-2 infection in healthy asymptomatic adults, the risk factors, and laboratory correlates. Design: We conducted a cross-sectional study during the outbreak. Presence of anti-SARS-CoV-2 IgM/IgG antibodies against the Nucleocapsid protein was assessed by a lateral flow immunoassay. Setting: Blood center at a leading academic hospital serving as COVID-19 referral center. Participants: We considered a random sample of blood donors since the sta…