Is it time to rethink infection control strategies for Hospital Norovirus outbreaks?

Is it time to rethink infection control strategies for Hospital Norovirus outbreaks?

Susy Mathew⁴, Leanne Dolan³, Jacquelyn Petty³, Andie Lee^1,2, Sebastiaan van Hal^1,2, ,

¹Department of Infectious Diseases and Microbiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
²Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
³Infection Prevention and Control, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
⁴Department of Microbiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
Introduction
An outbreak of Norovirus gastroenteritis occurred in two wards at Royal Prince Alfred Hospital, Sydney during December 2022 to January 2023. Outbreak management was implemented as per national guidelines. However, given ward closures and prolonged isolation can adversely impact patient care, we aimed to investigate the utility of rectal swabs (as an alternative to stool samples) and whole genome sequencing (WGS) to refine outbreak management.

Methods
Data regarding date of symptom onset, sample collection and results were collected. Stool was collected and sent for PCR from symptomatic patients. Rectal swabs were also collected from four stool PCR positive patients and tested by PCR. WGS was performed on PCR positive samples.

Results
27 patients in two adjacent wards (12 in geriatrics and 15 in neurosurgery) developed features of gastroenteritis; with 5 geriatric and 7 neurosurgery patients confirmed positive by faecal Norovirus PCR. The median duration between symptom onset and stool collection was 1 day. However, faeces were only able to be obtained between 1- and 4-days post symptom onset in 33% and 20% of geriatric and neurosurgery patients respectively. Rectal swabs were concordant with stool PCR while WGS revealed greater outbreak complexity than the epidemiology suggested.

Conclusion
Early identification of infectious patients through rapid sample testing is crucial to control Norovirus outbreaks. Rectal swabs are a potential alternate sampling method for norovirus detection which could expedite testing when stool samples are not readily available, particularly in elderly and/or immobile patients. WGS can be useful to better delineate outbreak extent.

Biography

Leanne is a Clinical Nurse Educator, and since 2019 has worked in the Infection Prevention and Control Department at Royal Prince Alfred Hospital, a 920-bed quaternary referral hospital located in Sydney, Australia.