Outbreak of Rotavirus Diarrheal Infection among Adults in King County, Washington, January-June 2023

Jimmy Ma; Raaka G Kumbhakar; Amanda Casto; Eric J Chow; Janet A Englund; Rashi Gautam; Jose Jaimes; Jacqueline E Tate; Sarah Smart; Nandita S Mani; Seth A Cohen; Abby Hussein; Krista Rietberg; Chloe Bryson-Cahn; Ferric C Fang

doi:10.1093/infdis/jiaf013

Outbreak of Rotavirus Diarrheal Infection among Adults in King County, Washington, January-June 2023

J Infect Dis. 2025 Jan 8:jiaf013. doi: 10.1093/infdis/jiaf013. Online ahead of print.

Authors

Jimmy Ma¹, Raaka G Kumbhakar¹, Amanda Casto¹, Eric J Chow^{1

2

3}, Janet A Englund⁴, Rashi Gautam⁵, Jose Jaimes⁵, Jacqueline E Tate⁵, Sarah Smart⁵, Nandita S Mani¹, Seth A Cohen¹, Abby Hussein¹, Krista Rietberg⁶, Chloe Bryson-Cahn¹, Ferric C Fang^{1

7}

Affiliations

¹ Division of Allergy & Infectious Diseases, University of Washington School of Medicine, Seattle, WA, USA.
² Public Health - Seattle & King County, Seattle, WA, USA.
³ Department of Epidemiology, University of Washington, Seattle, WA, USA.
⁴ Department of Pediatrics, Division of Pediatric Infectious Diseases, Seattle Children's Research Institute, Seattle, WA, USA.
⁵ Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
⁶ Infection Prevention and Control, Harborview Medical Center, Seattle, WA, USA.
⁷ Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, USA.

PMID: 39774704
DOI: 10.1093/infdis/jiaf013

Abstract

Rotavirus is a leading cause of diarrhea among children but less known as a cause among adults. We describe clinical, epidemiologic, and genotype characteristics of a rotavirus outbreak among adults in King County, Washington occurring January-June 2023. Adult rotavirus incidence in 2023 was ten times higher than the same period in 2022 (5% versus 0.5% samples). Disease severity was mild. G9P[4], an uncommon, non-vaccine strain in USA, was the predominant genotype. Genotyping suggested spillover from children with subsequent spread among adults. Our study highlights benefits of routine testing and genotyping during outbreaks for surveillance, tracking, and understanding implications on vaccination.

Keywords: adults; diarrhea; genotyping; rotavirus.

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