Duration of Enterovirus D68 RNA Shedding in the Upper Respiratory Tract and Transmission among Household Contacts, Colorado, USA.

Enterovirus D68 (EV-D68) causes cyclical outbreaks of respiratory disease and acute flaccid myelitis. EV-D68 is primarily transmitted through the respiratory route, but the duration of shedding in the respiratory tract is unknown. We prospectively enrolled 9 hospitalized children with EV-D68 respiratory infection and 16 household contacts to determine EV-D68 RNA shedding dynamics in the upper respiratory tract through serial midturbinate specimen collections and daily symptom diaries. Five (31.3%) household contacts, including 3 adults, were EV-D68-positive. The median duration of EV-D68 RNA shedding in the upper respiratory tract was 12 (range 7-15) days from symptom onset. The most common symptoms were nasal congestion (100%), cough (92.9%), difficulty breathing (78.6%), and wheezing (57.1%). The median illness duration was 20 (range 11-24) days. Understanding the duration of RNA shedding can inform the expected rate and timing of EV-D68 detection in associated acute flaccid myelitis cases and help guide public health measures.

Recruitment and retention of pediatric participants for pandemic preparedness research: Experience from the PREMISE EV-D68 Pilot Study.

Recruitment and retention are challenges for prospective pediatric cohort studies, particularly those involving serial venipunctures. We investigated factors underlying enrollment and retention in the Pandemic Response Repository through Microbial and Immune Surveillance and Epidemiology (PREMISE) Enterovirus D68 (EV-D68) Pilot Study, a multicenter prospective longitudinal cohort study assessing the utility of immunologic surveillance for pandemic preparedness. This study enrolls children ≤10 years for two blood draws, pre- and post-EV-D68 season, separated by 6-18 months. Overall, 174 children were enrolled in Cohort 1 of the study and 120 (69 %) of children completed the study, with follow-up blood samples obtained from 101 (58 %) of participants. Families were primarily motivated to participate by a desire to help other children, advance science, and better prepare for the next pandemic. Adding research blood draws to clinically indicated blood draws improved enrollment, and multiple study touch points facilitated retention. These findings can be applied to improve recruitment and retention in future pandemic preparedness efforts and longitudinal pediatric cohort studies.