Surveillance of lower respiratory tract infections outbreaks in nursing homes in France

Lower respiratory tract infections (LRTI) are the leading cause of infectious deaths in nursing homes. An early reporting procedure of LRTI outbreaks to local public health authorities was set up in France in 2006 in order to reduce the morbidity and the mortality related to these events. Local public health authorities reported these outbreaks to the French institute for Public Health Surveillance through a web application allowing a real-time exchange of information. Between August 2006 and July 2007, 64 outbreaks were reported. In more than 30% of the episodes, influenza virus was detected. On average, attacks rates were 22% for the residents and 7% for the staff. Staff members were affected in at least 56% of outbreaks. Average influenza vaccine uptake was 91% for the residents and 38% for the staff. The time for control measures implementation was 6.7 days on average and control measures were implemented after reporting in 36% of outbreaks. When control measures were implemented more than 2 days after the onset of the first case, the duration of outbreaks was longer (16.4 days vs. 8.3 days, P < 0.005) and residents had an increased rate of LRTI (P < 0.001) than when these measures were implemented earlier. These data show that the influenza immunization coverage for staff working in nursing homes is limited. The implementation of control measures is often delayed, although recommendations stress that they should start upon diagnosis of the first case. Reporting creates a dialog between nursing homes and public health professionals which facilitates outbreak management.