Persistent Norovirus Outbreak in a Long-Term Care Facility

BACKGROUND:    Over half of norovirus outbreaks reported in the United States occur in long-term care facilities (LTCF). Illness can be more severe among nursing home residents compared with otherwise healthy populations. We describe a persistent outbreak of norovirus infection occurring among residents, staff and visitors in a LTCF in Chicago that highlights challenges of controlling norovirus outbreaks in LTCF settings.

METHODS:   On February 1, 2015, Chicago Department of Public Health (CDPH) was informed of 12 cases of acute diarrhea and vomiting among LTCF residents with onsets from January 29–February 1. Stool samples were collected from four ill residents and tested for norovirus by the Illinois Department of Public Health Laboratory using reverse transcription polymerase chain reaction (RT-PCR). Symptoms among residents, staff and visitors of the LTCF were surveyed daily by LTCF staff and reported to CDPH. Cases were defined as vomiting or diarrhea with onset from January 27–February 23, 2015, occurring in persons with a positive norovirus PCR result or with no known alternative diagnosis. CDPH and infection control personnel inspected the facility on February 6, 2015.

RESULTS:   Fifty-two of 129 residents (40.3%), 27 of 187 staff members (14.4%), and one visitor met the case definition for norovirus infection. All four samples tested were positive for Norovirus GII. Case-patients were predominantly female (57/80; 71%); median age was 76.5 (range 20–100) years. Symptoms reported included diarrhea (68/80; 85%), vomiting (34/80; 42.5%), nausea (2/80; 2.5%), and fever (3/80; 3.75%). Median illness duration was 2 days. Four case-patients were hospitalized; one died of unrelated causes. Several factors were identified as contributing to ongoing transmission: use of a disinfecting agent that was not an EPA registered disinfectant effective against Norovirus, difficulty enforcing hand hygiene among residents with dementia, lapses in communication between staff and supervisors, and non-compliance with staff exclusion policies due to lack of paid time-off. Remedial actions included introduction of EPA registered disinfectants effective against norovirus, including bleach-detergent and advanced hydrogen peroxide products, engagement of staff to improve hand hygiene and high-touch surface disinfection on the dementia unit, and administrative interventions to improve communication and to provide paid time off for ill employees.

CONCLUSIONS:   Use of an inappropriate disinfecting agent, hygiene and communication lapses, and non-compliance with staff exclusion policies amplified person-to-person transmission of norovirus infection in this LTCF. Rapid and consistent implementation of infection control practices are critical to limit spread of norovirus infection in institutional settings.