Immunochromatographic SARS-CoV-2 IgG antibody assay: a cross-sectional study conducted at Wakayama Medical University in Japan [article]

Sadahiro Iwabuchi, Masahiro Katsuda, Yusuke Koizumi, Mayuko Hatai, Mitsue Kojima, Nahomi Tokudome, Shinobu Tamura, Machiko Nishio, Toshikazu Kondo, Masaya Hironisi, Chiemi Kakutani, Hiroki Yamaue (+1 others)
2021 medRxiv   pre-print
AbstractAsymptomatic patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection must be quickly identified and isolated to prevent the spread of the virus. The number of asymptomatic healthy people is completely unknown because they remain untested. Detection of specific SARS-CoV-2 antibodies has been widely accepted as a diagnostic test, and an immunochromatographic test, which is simpler and relatively cheaper than other methods, is becoming the gold standard for
more » ... tifying healthy people who had been infected with SARS-CoV-2 in the past. In this study, 1,528 volunteers who worked at a particular hospital were subjected to an immunochromatographic IgG test for SARS-CoV-2 to determine the ratio of asymptomatic people. Only 12 volunteers (0.79%) were IgG+, with no significant background differences in the sex, age, profession, experiences of working at the emergency department or caring for coronavirus disease 2019 patients. If this IgG+ ratio was to be extrapolated to Wakayama city's population, 2,780 out of 3,54,063 people may be asymptomatic for SARS-CoV-2. The results imply that anyone may get infected with SARS-CoV-2 but remain asymptomatic.
doi:10.1101/2021.01.10.21249421 fatcat:fnarfo7x2rdzxmwf4wun3l4t3u