Infectious Disease
A comparison of respiratory virus shedding patterns in a prospective longitudinal state-wide cohort Sarah Bassiouni* Sarah Bassiouni Dolapo Raheemat Raji Amy Callear Rachel Truscon Emileigh Johnson Arnold Monto Emily Martin
Background: Viral shedding has important implications for isolation and infection prevention guidelines. Our objective was to compare shedding of three respiratory viruses (RespV) among individuals in a community-based cohort over two consecutive RespV seasons.
Methods: Community Vaccine Effectiveness against Asymptomatic and Symptomatic SARS-CoV-2 Infection in Michigan is a prospective longitudinal cohort study that evaluates SARS-CoV-2 and other respiratory viruses year-round using weekly nasal swabs. Data was collected for RespV seasons 7/2022-6/2023 and 7/2023-6/2024. If participants met the case definition, they were considered symptomatic and collected an additional swab at onset; all specimens were PCR tested to determine RespV status. For this analysis, cessation of viral shedding was defined as the total duration of RespV positive swab results with two sequential negatives (RespV+/-/-).
Results: Results were analyzed from 25860 unique nasal swabs collected from 917 participants. Of those, 597 had specimens that were RespV+/-, with 95 positive for respiratory syncytial virus (RSV), 88 for SARS-CoV-2, and 45 for influenza. For participants who had specimens +/-/-, the median days to viral shedding cessation was: 7.0 (min=1, max=90) for RSV, 7.0 (min=3, max=41), and 7.0 (min=1, max=54) for influenza. Median RT-PCR cycle threshold values were comparable for all three respiratory viruses (RSV: 30.45, SARS-CoV-2: 31.4, and influenza: 31.00). A Bayesian analysis for interval censoring (using a semiparametric method under a proportional hazards model) is also in progress.
Conclusions: These findings reveal that, within this study population, time to viral shedding cessation was similar for all three RespV compared in this time frame. Median length of RespV shedding provides sufficient time for other household members to be exposed, thus disrupting patterns of RespV shedding within households can have major public health and infection prevention implications.
