Tara C Bouton1,2, Joseph Atarere2, Jacquelyn Turcinovic3,4, Scott Seitz5, Cole Sher-Jan3, Madison Gilbert2,6, Laura White7, Zhenwei Zhou7, Mohammad M Hossain3, Victoria Overbeck2,8, Lynn Doucette-Stamm9, Judy Platt10, Hannah E Landsberg10, Davidson H Hamer11,3,12, Catherine Klapperich9,10,13, Karen R Jacobson1,2, John H Connor5,3,13,4. 1. Section of Infectious Diseases, Boston University School of Medicine, Boston, MA, USA. 2. Boston Medical Center, Boston, MA, USA. 3. National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA. 4. BioInformatics Program, Boston University, Boston, MA, USA. 5. Department of Microbiology, Boston University School of Medicine, Boston, MA, USA. 6. Graduate Medical Sciences, Boston University School of Medicine, Boston, MA, USA. 7. Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA. 8. Boston University School of Public Health, Boston, MA, USA. 9. Boston University Clinical Testing Laboratory, Boston, MA, USA. 10. Boston University Student Health Services, Boston, MA, USA. 11. Department of Global Health, Boston University School of Public Health, Boston, MA, USA. 12. Center for Emerging Infectious Disease Research and Policy, Boston University, Boston, MA, USA. 13. Boston University Precision Diagnostics Center, Boston University, Boston, MA, USA.
Abstract
BACKGROUND: In January 2022, United States guidelines shifted to recommend isolation for 5 days from symptom onset, followed by 5 days of mask wearing. However, viral dynamics and variant and vaccination impact on culture conversion are largely unknown. METHODS: We conducted a longitudinal study on a university campus, collecting daily anterior nasal swabs for at least 10 days for RT-PCR and culture, with antigen rapid diagnostic testing (RDT) on a subset. We compared culture positivity beyond day 5, time to culture conversion, and cycle threshold trend when calculated from diagnostic test, from symptom onset, by SARS-CoV-2 variant, and by vaccination status. We evaluated sensitivity and specificity of RDT on days 4-6 compared to culture. RESULTS: Among 92 SARS-CoV-2 RT-PCR positive participants, all completed the initial vaccine series, 17 (18.5%) were infected with Delta and 75 (81.5%) with Omicron. Seventeen percent of participants had positive cultures beyond day 5 from symptom onset with the latest on day 12. There was no difference in time to culture conversion by variant or vaccination status. For 14 sub-study participants, sensitivity and specificity of day 4-6 RDT were 100% and 86% respectively. CONCLUSIONS: The majority of our Delta- and Omicron-infected cohort culture-converted by day 6, with no further impact of booster vaccination on sterilization or cycle threshold decay. We found that rapid antigen testing may provide reassurance of lack of infectiousness, though guidance to mask for days 6-10 is supported by our finding that 17% of participants remained culture positive after isolation.
BACKGROUND: In January 2022, United States guidelines shifted to recommend isolation for 5 days from symptom onset, followed by 5 days of mask wearing. However, viral dynamics and variant and vaccination impact on culture conversion are largely unknown. METHODS: We conducted a longitudinal study on a university campus, collecting daily anterior nasal swabs for at least 10 days for RT-PCR and culture, with antigen rapid diagnostic testing (RDT) on a subset. We compared culture positivity beyond day 5, time to culture conversion, and cycle threshold trend when calculated from diagnostic test, from symptom onset, by SARS-CoV-2 variant, and by vaccination status. We evaluated sensitivity and specificity of RDT on days 4-6 compared to culture. RESULTS: Among 92 SARS-CoV-2 RT-PCR positive participants, all completed the initial vaccine series, 17 (18.5%) were infected with Delta and 75 (81.5%) with Omicron. Seventeen percent of participants had positive cultures beyond day 5 from symptom onset with the latest on day 12. There was no difference in time to culture conversion by variant or vaccination status. For 14 sub-study participants, sensitivity and specificity of day 4-6 RDT were 100% and 86% respectively. CONCLUSIONS: The majority of our Delta- and Omicron-infected cohort culture-converted by day 6, with no further impact of booster vaccination on sterilization or cycle threshold decay. We found that rapid antigen testing may provide reassurance of lack of infectiousness, though guidance to mask for days 6-10 is supported by our finding that 17% of participants remained culture positive after isolation.
Authors: David C Hughes; John W Orchard; Emily M Partridge; Andre La Gerche; Carolyn Broderick Journal: J Sci Med Sport Date: 2022-06-07 Impact factor: 4.597
Authors: Miguel Garcia-Knight; Khamal Anglin; Michel Tassetto; Scott Lu; Amethyst Zhang; Sarah A Goldberg; Adam Catching; Michelle C Davidson; Joshua R Shak; Mariela Romero; Jesus Pineda-Ramirez; Ruth Diaz-Sanchez; Paulina Rugart; Kevin Donohue; Jonathan Massachi; Hannah M Sans; Manuella Djomaleu; Sujata Mathur; Venice Servellita; David McIlwain; Brice Gaudiliere; Jessica Chen; Enrique O Martinez; Jacqueline M Tavs; Grace Bronstone; Jacob Weiss; John T Watson; Melissa Briggs-Hagen; Glen R Abedi; George W Rutherford; Steven G Deeks; Charles Chiu; Sharon Saydah; Michael J Peluso; Claire M Midgley; Jeffrey N Martin; Raul Andino; J Daniel Kelly Journal: PLoS Pathog Date: 2022-09-12 Impact factor: 7.464