Limitations of Molecular and Antigen Test Performance for SARS-CoV-2 in Symptomatic and Asymptomatic COVID-19 Contacts.

Abstract

COVID-19 has brought unprecedented attention to the crucial role of diagnostics in pandemic control. We compared severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test performance by sample type and modality in close contacts of SARS-CoV-2 cases. Close contacts of SARS-CoV-2-positive individuals were enrolled after informed consent. Clinician-collected nasopharyngeal (NP) swabs in viral transport media (VTM) were tested with a routine clinical reference nucleic acid test (NAT) and PerkinElmer real-time reverse transcription-PCR (RT-PCR) assay; positive samples were tested for infectivity using a VeroE6TMPRSS2 cell culture model. Self-collected passive drool was also tested using the PerkinElmer RT-PCR assay. For the first 4 months of study, midturbinate swabs were tested using the BD Veritor rapid antigen test. Between 17 November 2020 and 1 October 2021, 235 close contacts of SARS-CoV-2 cases were recruited, including 95 with symptoms (82% symptomatic for ≤5 days) and 140 asymptomatic individuals. Reference NATs were positive for 53 (22.6%) participants; 24/50 (48%) were culture positive. PerkinElmer testing of NP and saliva samples identified an additional 28 (11.9%) SARS-CoV-2 cases who tested negative by reference NAT. Antigen tests performed for 99 close contacts showed 83% positive percent agreement (PPA) with reference NAT among early symptomatic persons, but 18% PPA in others; antigen tests in 8 of 11 (72.7%) culture-positive participants were positive. Contacts of SARS-CoV-2 cases may be falsely negative early after contact, but more sensitive platforms may identify these cases. Repeat or serial SARS-CoV-2 testing with both antigen and molecular assays may be warranted for individuals with high pretest probability for infection.

• Authors: Matthew L Robinson, Agha Mirza, Nicholas Gallagher, Alec Boudreau, Lydia Garcia Jacinto, Tong Yu, Julie Norton, Chun Huai Luo, Abigail Conte, Ruifeng Zhou, Kim Kafka, Justin Hardick, David D McManus, Laura L Gibson, Andrew Pekosz, Heba H Mostafa, Yukari C Manabe
• Journal: Journal of clinical microbiology (J Clin Microbiol) Vol. 60 Issue 7 Pg. e0018722 (07 20 2022) ISSN: 1098-660X [Electronic] United States
• PMID: 35730949 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Topics

• COVID-19 (diagnosis)
• COVID-19 Testing
• Humans
• Pandemics
• SARS-CoV-2
• Sensitivity and Specificity