[Inpatient and personnel vaccination influence on influenza outbreaks in long-term medical and care hospital].

The influence of the vaccination rate among inpatients and hospital personnel on the risk of influenza outbreaks in long-term medical and care hospital was investigated. Vaccination rates and the annual number of influenza cases were analyzed from 2003/2004 to 2008/ 2009. During the first three influenza seasons, vaccination among inpatients was low-45.4% in 2003/4, 49.7% in 2004/5, and 57.5% in 2005/6. Minor influenza outbreaks accounted for 22 patients in 2003/4, 10 in 2004/5, and 10 in 2005/6. During the next three seasons, vaccination was higher than in the previous years, at follows: 65.8% in 2006/7, 65.6% in 2007/8, and 72.0% in 2008/9. This improvement apparently accounted for the absence of outbreaks during these seasons, with patients numbering 0 in 2006/7 and 2 each in 2007/8 and 2008/9. A strong negative correlation thus exist between inpatient vaccination rates and the number of influenza patients (r = -0.903, p = 0.014). The vaccination rate among hospital personnel was high at 79.3%-91.2% throughout the study, and no correlation was seen between hospital personnel vaccination and the number of influenza patients (r = 0.379, p = 0.459). No correlation was seen, either, between the number of influenza patients and national influenza occurrence (r = - 0.146, p = 0.783). This results thus indicate that a high vaccination rate among hospital personnel is not enough to prevent influenza outbreaks, making it important to raise vaccination rates among both inpatients and hospital personnel if influenza outbreaks are to be controlled and prevented.