Two norovirus outbreaks: Same nurse manager, different outcomes

Background: Houston Department of Health and Human Services (HDHHS) investigated two norovirus outbreaks at two assisted living facilities in Houston. The director of nursing at the prior nursing home, later became the director of nursing in another nursing home with a similar outbreak. Methods: In March 2007, the first outbreak was reported to HDHHS on day 16 of onset. At reporting, 36 of 127 residents were ill and the illness had spread to all units of the facility. Recommended control measures included room isolation of ill residents and work exclusion of ill staff for four days post-symptoms; however, management delayed enforcement of these recommendations. In December 2007, the same nurse manager employed by the new facility of 350 residents reported the second outbreak to HDHHS on day 9 of onset. She immediately adopted recommended control measures. Recommendations were similar for both facilities. Results: The first outbreak was contained by day 32. In all, 71 residents became sick (attack rate 56%), and two residents died. The second outbreak was contained by day 16. The spread of disease in the second outbreak was limited to two floors (out of 17 floors); 28 residents became sick (attack rate 8%), and none died. Conclusion: The control of norovirus outbreaks at assisted living facilities is dependent on the early reporting of the outbreak to the local health department and the cooperation of management in enforcing recommendations. The swift adoption of the control measures enabled the second facility to lessen the severity of the second outbreak.