Jira Chansaenroj1, Ritthideach Yorsaeng1, Nawarat Posuwan1, Jiratchaya Puenpa1, Natthinee Sudhinaraset1, Chintana Chirathaworn1,2,3, Yong Poovorawan4. 1. Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand. 2. Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand. 3. Tropical Medicine Cluster, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand. 4. Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand. Yong.P@chula.ac.th.
Abstract
BACKGROUND: Efficient monitoring and control of coronavirus disease 2019 (COVID-19) require access to diagnostic tests, and serological diagnostic testing is desirable. In the current study, antibodies were investigated in patients recently diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: Cross-sectional data were obtained from 245 patients in whom SARS-CoV-2 infection had been confirmed via real-time reverse transcriptase-polymerase chain reaction between March and October 2020. Serum samples were acquired between 2 and 60 days following the onset of COVID-19 symptoms or the first detection of SARS-CoV-2 in asymptomatic patients. All specimens were tested simultaneously using an IgM/IgG rapid diagnostic test (RDT), IgG nucleocapsid protein-based chemiluminescent microparticle immunoassay (CMIA), IgG, and IgA spike protein-based enzyme-linked immunosorbent assays (ELISAs). Blood donor samples obtained in 2018 were used as negative controls. RESULTS: The sensitivity and specificity of the RDT IgG were compared with the IgG immunoassays as standards. The RDT IgG exhibited 97.5% sensitivity and 89.4% specificity compared with a CMIA IgG, 98.4% sensitivity, and 78.8% specificity compared with an ELISA IgG. IgM, IgG, and IgA seropositivity rates were low between 1 and 2 weeks after COVID-19 symptom onset or the detection of SARS-CoV-2 RNA. IgM seropositivity rate began decreasing after 4 weeks, whereas IgG and IgA seropositivity rate remained at appreciable levels over the 8-week study period. No cross-reactivity with seasonal coronaviruses was detected. CONCLUSIONS: IgG RDT alone or combined with molecular diagnostic tests may be useful for identifying recent SARS-CoV-2 infection.
BACKGROUND: Efficient monitoring and control of coronavirus disease 2019 (COVID-19) require access to diagnostic tests, and serological diagnostic testing is desirable. In the current study, antibodies were investigated in patients recently diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: Cross-sectional data were obtained from 245 patients in whom SARS-CoV-2 infection had been confirmed via real-time reverse transcriptase-polymerase chain reaction between March and October 2020. Serum samples were acquired between 2 and 60 days following the onset of COVID-19 symptoms or the first detection of SARS-CoV-2 in asymptomatic patients. All specimens were tested simultaneously using an IgM/IgG rapid diagnostic test (RDT), IgG nucleocapsid protein-based chemiluminescent microparticle immunoassay (CMIA), IgG, and IgA spike protein-based enzyme-linked immunosorbent assays (ELISAs). Blood donor samples obtained in 2018 were used as negative controls. RESULTS: The sensitivity and specificity of the RDT IgG were compared with the IgG immunoassays as standards. The RDT IgG exhibited 97.5% sensitivity and 89.4% specificity compared with a CMIA IgG, 98.4% sensitivity, and 78.8% specificity compared with an ELISA IgG. IgM, IgG, and IgA seropositivity rates were low between 1 and 2 weeks after COVID-19 symptom onset or the detection of SARS-CoV-2 RNA. IgM seropositivity rate began decreasing after 4 weeks, whereas IgG and IgA seropositivity rate remained at appreciable levels over the 8-week study period. No cross-reactivity with seasonal coronaviruses was detected. CONCLUSIONS: IgG RDT alone or combined with molecular diagnostic tests may be useful for identifying recent SARS-CoV-2 infection.
Authors: Camilla Rothe; Mirjam Schunk; Peter Sothmann; Gisela Bretzel; Guenter Froeschl; Claudia Wallrauch; Thorbjörn Zimmer; Verena Thiel; Christian Janke; Wolfgang Guggemos; Michael Seilmaier; Christian Drosten; Patrick Vollmar; Katrin Zwirglmaier; Sabine Zange; Roman Wölfel; Michael Hoelscher Journal: N Engl J Med Date: 2020-01-30 Impact factor: 91.245