Quantitative SARS-CoV-2 viral-load curves in paired saliva and nasal swabs inform appropriate respiratory sampling site and analytical test sensitivity required for earliest viral detection.

Autor:	Savela ES; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Winnett A; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Romano AE; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Porter MK; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Shelby N; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Akana R; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Ji J; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Cooper MM; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Schlenker NW; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Reyes JA; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Carter AM; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Barlow JT; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125., Tognazzini C; City of Pasadena Public Health Department, 1845 N. Fair Oaks Ave., Pasadena, CA, USA 91103., Feaster M; City of Pasadena Public Health Department, 1845 N. Fair Oaks Ave., Pasadena, CA, USA 91103., Goh YY; City of Pasadena Public Health Department, 1845 N. Fair Oaks Ave., Pasadena, CA, USA 91103., Ismagilov RF; California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125.
Jazyk:	angličtina
Zdroj:	MedRxiv : the preprint server for health sciences [medRxiv] 2021 Aug 26. Date of Electronic Publication: 2021 Aug 26.
DOI:	10.1101/2021.04.02.21254771
Abstrakt:	Early detection of SARS-CoV-2 infection is critical to reduce asymptomatic and pre-symptomatic transmission, curb the spread of variants by travelers, and maximize treatment efficacy. Low-sensitivity nasal-swab testing (antigen and some nucleic-acid-amplification tests) is commonly used for surveillance and symptomatic testing, but the ability of low-sensitivity nasal-swab tests to detect the earliest stages of infection has not been established. In this case-ascertained study, initially-SARS-CoV-2-negative household contacts of individuals diagnosed with COVID-19 prospectively self-collected paired anterior-nares nasal-swab and saliva samples twice daily for viral-load quantification by high-sensitivity RT-qPCR and digital-RT-PCR assays. We captured viral-load profiles from the incidence of infection for seven individuals and compared diagnostic sensitivities between respiratory sites. Among unvaccinated persons, high-sensitivity saliva testing detected infection up to 4.5 days before viral loads in nasal swabs reached the limit of detection of low-sensitivity nasal-swab tests. For most participants, nasal swabs reached higher peak viral loads than saliva, but were undetectable or at lower loads during the first few days of infection. High-sensitivity saliva testing was most reliable for earliest detection. Our study illustrates the value of acquiring early (within hours after a negative high-sensitivity test) viral-load profiles to guide the appropriate analytical sensitivity and respiratory site for detecting earliest infections. Such data are challenging to acquire but critical to design optimal testing strategies in the current pandemic and will be required for responding to future viral pandemics. As new variants and viruses emerge, up-to-date data on viral kinetics are necessary to adjust testing strategies for reliable early detection of infections. Competing Interests: COMPETING INTERESTS STATEMENT RFI is a co-founder, consultant, and a director and has stock ownership of Talis Biomedical Corp. In addition, RFI is an inventor on a series of patents licensed by the University of Chicago to Bio-Rad Laboratories Inc. in the context of ddPCR.
Databáze:	MEDLINE
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