Recurring, annual attacks of norovirus affect resident/patient and staff safety, disrupt healthcare facility operations, and may result in financial and operational burden to facilities. Key components of an outbreak prevention/containment program include addressing risk factors that increase the potential for norovirus infection and applying best practices to identify and control an acute gastroenteritis outbreak.

Pennsylvania long-term care (LTC) facilities report gastrointestinal (GI) infections, including norovirus, to the Pennsylvania Patient Safety Authority through its Pennsylvania Patient Safety Reporting System. In April 2014, in accord with changes to national standards, the Authority revised the LTC criteria for identifying and reporting gastroenteritis. The revision included a new gastroenteritis subcategory that allows detailed surveillance and reporting of norovirus cases separate from other causes of gastroenteritis within PA-PSRS.

Norovirus events comprised the majority of GI infections for 12 of 36 months in three clusters of consecutive months concurrent with what is commonly considered the norovirus season (Figure 2). These three clusters accounted for 87.5% of all norovirus reports over the three-year period.

Also of note are the seasonal spikes of monthly norovirus rates as compared to relatively stable monthly rates of other GI infections (Figure 3).  

The timing and magnitude of event clusters varied among facilities, as shown when grouped by Pennsylvania region (Figure 4). Each region had different monthly peaks, demonstrating that although events are seasonal, variability exists by region. Table 1 shows peak norovirus periods and rates for the Authority's six state regions.

Excerpted from: Bradley S, Finley E. Combat norovirus infections in long-term care facilities. Pa Patient Saf Advis 2018 Jun;15(2). http://patientsafety.pa.gov/ADVISORIES/Pages/201806_NorovirusUpdate.aspx.