Finally, seroprevalence can vary according to different populations, such as pregnant women and hemodialysis patients; however, limited studies have examined these associations. thought to be no higher than that in other groups. With regard to sex, no statistically significant difference has been found between male and female subjects. Some, but not all, studies have shown that children have a lower risk than other age groups. Finally, seroprevalence can vary according to different populations, such as pregnant women and hemodialysis patients; however, limited studies have examined these associations. Furthermore, the continued surveillance of seroprevalence is usually warranted to estimate and monitor the growing burden of COVID-19. Keywords:Antibody, COVID-19, SARS-CoV-2, Population-based survey, Seroprevalence == Introduction == Even though severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) only emerged at the end of 2019, the associated diseasecoronavirus disease 2019 (COVID-19)has spread rapidly to more than 180 countries/regions worldwide and has (E)-2-Decenoic acid consequently led to a global pandemic (World Health Business (WHO), 2020). As of September 7, 2020, nearly 27 million COVID-19 cases have been reported worldwide, causing 876,616 deaths, with an associated case fatality rate of 3.3% (World Health Organization (WHO), 2020,Lai et al., 2020a,Lai et al., 2020b,Sheng et al., 2020). Currently, the diagnosis of COVID-19 is confirmed by the detection of SARS-CoV-2 via real-time reverse transcription polymerase chain reaction (qRT-PCR) assays that target open reading frame-1 antibodies, envelope proteins, nucleocapsid proteins, RNA-dependent RNA polymerase genes, and the N1, N2, and N3 target genes, among suspected cases with an exposure history and signs/symptoms of SARS-CoV-2 infection (Lai et al., 2020c). However, the clinical manifestations of COVID-19 include both respiratory and extra-respiratory signs and symptoms and can range from an asymptomatic mild disease to severe disease/acute respiratory tract infections (Lai et al., 2020d,Lai et al., 2020e,Li (E)-2-Decenoic acid et al., 2020a,Li et al., 2020b). Therefore, misdiagnosis of COVID-19 can occur in patients without a characteristic presentation, even for asymptomatic and mild infections, and in places where qRT-PCR is Rabbit Polyclonal to Cytochrome P450 2S1 unavailable. These issues could limit our understanding of (E)-2-Decenoic acid the extent of SARS-CoV-2 infection and further affect the implementation of infection control and prevention policies. To resolve this issue, the use of a serological test to detect anti-SARS-CoV-2 antibodies could be a better way to estimate the burden of SARS-CoV-2 infection than the PCR method, and help improve understanding of the associated epidemiology (Lai et al., 2020c,Eckerle and Meyer, 2020,Ko et al., 2020). Hence, this review was conducted to provide updated and comprehensive information about the seroprevalence of the SARS-CoV-2 antibody in different populations. == Population-based seroprevalence studies == == Europe == Several large population-based studies have been conducted in COVID-19 hotspots (Polln et al., 2020,Stringhini et al., 2020,Fiore et al., 2020,Vena et al., 2020,Gallian et al., 2020,Bogogiannidou et al., 2020,Silveira et al., 2020,Amorim Filho et al., 2020,Sood et al., 2020,Ng et al., 2020,Rosenberg et al., 2020,Havers et al., 2020,Nir et al., 2020,Sutton et al., 2020,McLaughlin et al., 2020,Naranbhai et al., 2020,Xu et al., 2020,Chughtai et al., 2020,Younas et al., 2020,Sam et al., 2020). In Spain, a nationwide, population-based sero-epidemiological study was conducted from April 27 to May 11, 2020 (Encuesta Seroepidemiolgica de la Infeccin por el Virus SARS-COV-2 en Espaa; ENE-COVID). In that study, 202,35,883 households were initially selected from the municipal rolls, using a two-stage random sampling method with stratification by province and municipality size. A total of 61,075 participants received the point-of-care test (Orient Gene Biotech COVID-19 IgG/IgM Rapid Test Cassette; Zhejiang Orient Gene Biotech, Zhejiang, China; reference GCCOV-402a), and among them, 51,958 further received a chemiluminescent microparticle immunoassay for the qualitative detection of IgG against SARS-CoV-2 nucleoprotein (SARS-CoV-2 IgG for use with ARCHITECT; Abbott Laboratories, Abbott Park, IL, USA; reference 06R8620). The seroprevalence was found to be 5.0% (95% confidence interval (CI) 4.75.4%) by the point-of-care test and 4.6% (95% CI 4.35.0%) by the immunoassay, with a specificitysensitivity range of 3.7% (95% CI 3.34.0%; both tests positive) to 6.2% (95% CI 5.86.6%; either test positive) (Polln et al., 2020). A study in Switzerland reported the preliminary results of the surveillance of 2766 participants from 1339 households, with a demographic distribution similar to that of the canton of Geneva, between April 6 and May 9, 2020 (Stringhini et al., 2020). In that study, 12 weekly seroprevalence surveys, using a commercially available ELISA (Euroimmun; Lbeck, Germany; #EI (E)-2-Decenoic acid 2606-9601.