General characteristics

• Less nursing homes participated in the SNIV network in 2012 (N=19) than in the previous years (2009 N=25; 2010 N=28; 2011 N=25).
• Nursing homes with lower bed capacity (median 134) tended to participate in 2012 and furthermore, the bed capacity of some of the participating nursing homes decreased.
• Nursing homes with higher percentage of private rooms and private bathrooms tended to participate in 2012 and furthermore, the capacity of private rooms and private bathrooms increased in some of the participating nursing homes due to renovation.
• Seasonal influenza vaccination coverage of personnel stayed low in 2012 (median 18%).

Gastro-enteritis

• In 2012 in SNIV participating nursing homes registered in total 276 episodes of gastro-enteritis.
• Incidence showed a clear seasonal pattern with peaks in winter. In 2012 the maximum four week average was 7.8 per 1000 resident weeks.
• Nursing homes with regular interchange of personnel between wards had higher incidences of gastro-enteritis. A hypothesis might be that interchange of personnel facilitates the spread of pathogens that cause gastro-enteritis.

Influenza-like illness

• In 2012 in SNIV participating nursing homes registered in total 197 episodes of influenza-like illness.
• Incidence showed in 2012 a clear seasonal pattern with peaks in winter. In 2012 the maximum four week average was 5.7 per 1000 resident weeks.
• The peak at the beginning of 2012 coincided with detections of A(H3N2) influenza virus in swabs taken from residents with influenza-like illness or another acute respiratory infection.
• The peak at the end of 2012 no influenza viruses were detected. However, in one nursing home a small outbreak of RSV-B infections was detected, which accounted also for the peak in number of swabs in week 50 of 2012.
• Nursing homes with a higher seasonal influenza vaccination coverage among personnel had lower incidences of influenza-like illness.

Probable pneumonia

• In 2012 in SNIV participating nursing homes registered in total 388 episodes of probable pneumonia, which makes probable pneumonia the second most reported infection within the SNIV network.
• No clear peaks in incidence were observed.
• Nursing homes with a higher percentage of private bathrooms had higher incidences of probable pneumonia. A hypothesis might be that private bathrooms probably are less often used and therefore might be a possible source of legionella. Further study of pathogens in residents with probable pneumonia is necessary to gain more insight.

Urinary tract infections

• In 2012 in SNIV participating nursing homes registered in total 805 episodes of urinary tract infections, which makes urinary tract infections the most reported infection within the SNIV network.
• No clear peaks in incidence were observed, but registration started in the second quarter of 2011.

Mortality

• In 2012 in SNIV participating nursing homes registered in total 388 deaths.
• The mortality rate in 2012 exceeded that of previous years and was lowest in the third quarter of 2012.
• Association with infection incidence will be subject of further analyses.