Vaccination coverage for seasonal influenza among residents and health care workers in Norwegian nursing homes during the 2012/13 season, a cross-sectional study

BMC Public Health Vaccination coverage for seasonal influenza among residents and health care workers in Norwegian nursing homes during the 2012/13 season, a cross-sectional study Horst Bentele 0 1 Marianne R Bergsaker 2 Siri Helene Hauge 1 Jrgen V Bjrnholt 1 0 European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC) , Stockholm , Sweden 1 Department of Infection Control Epidemiology, Norwegian Institute of Public Health , Oslo , Norway 2 Department of Vaccines, Norwegian Institute of Public Health , Oslo , Norway Background: WHO has set a goal of 75% vaccination coverage (VC) for seasonal influenza for residents and also recommends immunization for all healthcare workers (HCWs) in nursing homes (NHs). We conducted a cross-sectional study to estimate the VC for seasonal influenza vaccination in Norwegian NHs in 2012/2013 since the VC in NHs and HCWs is unknown. Methods: We gathered information from NHs concerning VC for residents and HCWs, and vaccination costs for HCWs, using a web-based questionnaire. We calculated VC among NH residents by dividing the number of residents vaccinated by the total number of residents for each NH. VC among HCWs was similarly calculated by dividing the number of HCWs vaccinated by the total number of HCWs for each NH. The association between VC and possible demographic variables were explored. Results: Of 910 NHs, 354 (38.9%) responded. Median VC per NH was 71.7% (range 0-100) among residents and 0% (range 0-100) among HCWs, with 214 (60%) NHs reporting that none of their HCWs was vaccinated. Median VC for HCWs in NHs with an annual vaccination campaign was 0% (range 0-53), compared to when they did not have an annual vaccination campaign 0% (range 0-12); the distributions in the two groups differed significantly (Mann-Whitney U, P = 0.006 two tailed). Conclusion: Median influenza VC in Norwegian NHs was marginally lower than recommended among residents and exceptionally low among HCWs. The VC in HCWs was significantly higher when NHs had an annual vaccination campaign. We recommend that NHs implement measures to increase VC among residents and HCWs, including vaccination campaigns and studies to identify potential barriers to vaccination. - Background Residents in nursing homes (NHs) and long-term care facilities (LTCF) are at higher risk of severe respiratory tract infections owing to old age, the number of underlying illnesses, and close living conditions [1-3]. The main vaccine- preventable respiratory tract infection is caused by the influenza virus. The infection can be severe and even lethal, and viral infections often predispose sufferers to bacterial secondary infections and complications [4]. Further, although the lethality of influenza infection is low, the resulting reduced general condition following infection is of major importance in the elderly. Accordingly, the World Health Organization (WHO) defines NHs residents as a risk group for severe influenza and recommends vaccination coverage (VC) of at least 75%. The main goals are to reduce risk of severe disease and to prevent outbreaks. The WHO recommendation also includes influenza vaccination of health care workers (HCWs) in order to prevent introduction of the disease into healthcare institutions [5,6]. The Norwegian guidelines for infectious disease control follow the WHO recommendations relating to seasonal influenza, the aim being to achieve a minimum VC of 75% in Norwegian NHs [7]. Seasonal influenza vaccination for residents in NHs is reimbursed by the state in Norway. This is in contrast to influenza vaccination of HCWs, for whom each employer decides whether it is to be given free of charge. The yearly influenza vaccination is normally conducted during October and November [7]. The Vaccine European New Integrated Collaboration Effort (VENICE) report, covering the 2011/2012 season, showed seasonal influenza VC for the general Norwegian population above 65 years and for all HCWs to be 36% and 12% respectively [8]. However, the VC among residents and HCWs in NHs is unknown. To guide development of vaccination programs for residents and HCWs in NHs, data on VC is crucial. We therefore conducted a cross-sectional study approaching all NHs in Norway in order to estimate VC for seasonal influenza vaccine among both residents and HCWs. In addition, we investigated whether there was an association between VC and response rate by county, yearly vaccination campaigns among residents and HCWs, free-of-charge vaccination of HCWs, NH size (number of residents) and geographic location. Methods Population and data collection In December 2012 we invited NH managers and NH physicians to participate in an electronic survey. The invitation was sent to all 429 municipalities in Norway with the instruction to forward the e-mail to all the NHs located in the respective municipality. After six weeks a reminder was sent to the same e-mail-addresses. The total number of residents in NHs in the different counties was obtained from Statistics Norway [9]. In 2011, 910 NHs with a total of 34,795 long-term-care residents were registered in Norway. The questionnaire (Additional file 1) was developed in QuestBack to collect aggregated data from each NH. The questionnaire contained 10 closed questions regarding seasonal influenza vaccination of residents and HCWs. We also collected general information from the NHs, including geographic location, number of longterm-care residents, number of personnel working in direct contact with the residents, whether influenza vaccination of HCWs was given free of charge and, if not, how much personnel had to pay, and if the NHs had annual vaccination campaigns. Definitions and data analyses In Norway, a NH is defined as residential facilities for elderly people with the primary purpose of providing a continuous 24-hour professional health-care service. In this study we only included long-term-care residents with registered home address at the NHs, since their medical service, including vaccination, is provided by the NH. We defined a resident as a person with registered home address at the NH. We defined an HCW as an employee at an NH who has regular physical contact with the residents. This includes doctors, nurses, auxiliary nurses, occupational therapists, physiotherapists, and students. VC among NH residents was calculated by dividing the number of residents vaccinated by the total number of residents for each NH. Similarly, VC among HCWs was calculated by dividing the number of HCWs vaccinated by the total number of HCWs for each NH, thereby defining NH as unit of analysis. VC is presented as median per county to avoid revealing the NH identity on a municipality level. We compared the VC between NHs where HCWs had to pay for their vaccination and those who got it for free using a Mann-Whitney U-test. Similarly, we compared the VC in both residents and HCWs in NHs who had an a (...truncated)