• A Hemagglutination-Based Semiquantitative Test for Point-of-Care Determination of SARS-CoV-2 Antibody Levels.

      Kruse, Robert L; Huang, Yuting; Lee, Alyssa; Zhu, Xianming; Shrestha, Ruchee; Laeyendecker, Oliver; Littlefield, Kirsten; Pekosz, Andy; Bloch, Evan M; Tobian, Aaron A R; et al. (American Society for Microbiology, 2021-09-01)
      Serologic point-of-care tests to detect antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are an important tool in the COVID-19 pandemic. The majority of current point-of-care antibody tests developed for SARS-CoV-2 rely on lateral flow assays, but these do not offer quantitative information. To address this, we developed a novel antibody test leveraging hemagglutination, employing a dry card format currently used for typing ABO blood groups. Two hundred COVID-19 patient and 200 control plasma samples were reconstituted with O-negative red blood cells (RBCs) to form whole blood and added to dried viral-antibody fusion protein, followed by a stirring step and a tilting step, 3-min incubation, and a second tilting step. The sensitivities of the hemagglutination test, Euroimmun IgG enzyme-linked immunosorbent assay (ELISA), and receptor binding domain (RBD)-based CoronaChek lateral flow assay were 87.0%, 86.5%, and 84.5%, respectively, using samples obtained from recovered COVID-19 individuals. Testing prepandemic samples, the hemagglutination test had a specificity of 95.5%, compared to 97.3% and 98.9% for the ELISA and CoronaChek, respectively. A distribution of agglutination strengths was observed in COVID-19 convalescent-phase plasma samples, with the highest agglutination score (4) exhibiting significantly higher neutralizing antibody titers than weak positives (2) (P < 0.0001). Strong agglutinations were observed within 1 min of testing, and this shorter assay time also increased specificity to 98.5%. In conclusion, we developed a novel rapid, point-of-care RBC agglutination test for the detection of SARS-CoV-2 antibodies that can yield semiquantitative information on neutralizing antibody titer in patients. The 5-min test may find use in determination of serostatus prior to vaccination, postvaccination surveillance, and travel screening.
    • Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Seroprevalence in Decedents Undergoing Forensic Postmortem Examination: Feasibility for 
Real-Time Pandemic Surveillance.

      Coburn, Sally B; Manabe, Yukari C; Laeyendecker, Oliver; Sherman, Susan G; Baker, Owen R; Quinn, Thomas C; Graham, Lindsey A; Dennis Thomas, F; Southall, Pamela; Weedn, Victor W; et al. (Oxford University Press, 2022-04-10)
      Among 1906 decedents, 305 (16%) were positive for SARS-CoV-2 antibodies. Monthly seroprevalence increased from 11% to 22% over time and was consistently higher than state-level estimates of testing positivity. Hispanic ethnicity was associated with 2- to 3.2-fold higher seropositivity (P < .05) irrespective of sex. Deaths due to motor vehicle crash were associated with 62% increased seropositivity (aPR, 1.62 [95% CI, 1.15-2.28]) vs natural manner of death. Though seroprevalence was lower in decedents of illicit drug overdose vs nonoverdose in early months, this shifted, and seroprevalence was comparable by November 2020.
    • Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Status in Decedents Undergoing Forensic Postmortem Examination in Maryland, May 24 to June 30, 2020

      Althoff, Keri N; Laeyendecker, Oliver; Li, Rong; Coburn, Sally B; Klock, Ethan; Baker, Owen R; Quinn, Thomas C; Michael, Jeffrey; Shields, Wendy C; Ehsani, Johnathon; et al. (Oxford University Press, 2020-12-15)
      Seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies was 10% among the subset of decedents undergoing forensic postmortem examination in June in Maryland. Decedents of motor vehicle crashes had similar seroprevalence compared with those with a natural death (including decedents with SARS-CoV-2 infection). Decedents of motor vehicle crashes may be a sentinel surveillance population. © 2020 The Author(s) 2020.