Seroprevalence of SARS-CoV-2–Specific Antibodies among Quarantined Close Contacts of COVID-19 Patients, Faroe Islands, 2020

• DOI: 10.3201/eid2711.204948
• Publication Date: 2021-10-20T02:11:29Z
• Authors: Maria Skaalum Pet...; Marnar Fríðheim K...; Halla Weihe Reinert; Jógvan Páll Fjall...; Debes Hammershaim...; Shahin Gaini; Bjarni á Steig; Lars Fodgaard Møller; Marin Strøm; Pál Weihe
• Keywords: 0301 basic medicine; Family Characteristics; SARS-CoV-2; Research; R; COVID-19; Infectious and parasitic diseases; RC109-216; 3. Good health; close contacts; 03 medical and health sciences; 0302 clinical medicine; secondary attack rate; Seroepidemiologic Studies; Quarantine; Faroe Islands; Medicine; Humans; SARS-CoV-2 seroprevalence; Aged

Close contacts of coronavirus disease (COVID-19) patients are at high risk for severe acute respiratory syndrome 2 (SARS-CoV-2) infection. We assessed the seroprevalence of SARS-CoV-2-specific antibodies among quarantined close contacts of COVID-19 patients in the Faroe Islands. We invited quarantined close contacts of COVID-19 index patients identified during March 3-April 22, 2020, to participate in this study; 584 (81%) contacts consented and underwent serologic testing. Among the 584 participants, 32 (5.5%) were seropositive for total antibody against SARS-CoV-2. Household and young or elderly contacts had higher risk for seropositivity than other contacts. We found a secondary attack rate of 19.2%. Seroprevalence among close contacts was almost 10-fold higher than among the general population of the Faroe Islands. Regularly testing household close contacts of COVID-19 patients might help track the transmission of SARS-CoV-2.