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Influenza vaccination coverage among hospital personnel over three consecutive vaccination campaigns (2001–2002 to 2003–2004)
Vaccine 25 (2007) 201–204
Influenza vaccination coverage among hospital personnel over three consecutive vaccination campaigns (2001–2002 to 2003–2004) J.R. de Juanes a,∗ , A. Garc´ıa de Codes a , M.P. Arrazola a , F. Ja´en a , M.I. Sanz a , A. Gonz´alez b a
Preventive Medicine Service, Jefe de Servicio de Medicina Preventiva, Hospital “12 de Octubre”, Carretera de Andaluc´ıa Km 5, 28041 Madrid, Spain b Medical Department, Sanofi Pasteur MSD, Madrid, Spain Received 4 September 2005; received in revised form 8 October 2005; accepted 11 October 2005 Available online 1 December 2005
Abstract This study was carried out to assess influenza vaccination coverage among hospital personnel and the impact of health promotion campaigns, within the hospital, designed to increase vaccination coverage over three consecutive vaccination campaigns (2001–2002 to 2003–2004). The health promotion tool used in the 2001–2002 and 2002–2003 were informative posters distributed throughout the hospital. In the 2003–2004 season, the recommendation was also published in the internal bulletin and Web site of the hospital. In addition, a physician and a nurse from the Department of Preventive Medicine visited all departments offering vaccination in the work place. The overall vaccination coverage in the 2001–2002 campaign was 16% with coverage of 11.5% in nurses and 15% in physicians. In the 2002–2003 and 2003–2004 campaigns the overall vaccination coverage was 21% and 40%, respectively (p < 0.01). Staff physicians and resident physicians reached 60 and 42% coverage rates in the 2003–2004 campaign, but coverage in nurses and nursing assistant remained around 30% (p < 0.01). In summary, influenza vaccination coverage among hospital based healthcare personnel increased significantly during the last three seasons, however, it still remains low despite active attempts at promoting influenza vaccination. © 2006 Published by Elsevier Ltd. Keywords: Health-care workers; Influenza; Vaccination
1. Introduction Influenza is among the leading causes of respiratory infection and it represents a significant public health burden. Elderly people and patients with underlying health conditions are at increased risk of complications of influenza, including hospitalization and death [1]. During epidemics, the hospitalization rate for the elderly and people with chronic health problems may increase two to five-fold compared with nonepidemic periods [1]. Healthcare workers (HCWs) who are clinically or sub-clinically infected can transmit influenza virus to persons at risk for complications of influenza [2]. For ∗ Corresponding author. Tel.: +34 1 3908026; fax: +34 91 3908582/4018622. E-mail address: [email protected] (J.R. de Juanes).
0264-410X/$ – see front matter © 2006 Published by Elsevier Ltd. doi:10.1016/j.vaccine.2005.10.057
this reason, annual vaccination against influenza is recommended for HCWs [2]. However, despite recommendations some studies show that HCWs have low rates of acceptance of vaccination [2,3]. Acquisition of influenza by HCWs may cause absenteeism and significant disruption of health care, but also serves as the source for nosocomial transmission to patients and hospital staff [4–7]. During epidemics, attack rates ranging from 25 to 80% are observed among both patients and staff [8–10]. However, patients in facilities in which more than 60% of the healthcare personnel were vaccinated experienced less influenza related morbidity and mortality than patients in centers whose personnel were not vaccinated [11–13]. This suggests that Health care institutions should offer and encourage the use of influenza vaccine among HCWs. However, HCWs cite a number of barriers to influenza vaccination. These barriers include incon-
202
J.R. de Juanes et al. / Vaccine 25 (2007) 201–204
venient vaccine administration or concerns about potential side effects [14–16]. Some interventions, such as the use of a mobile cart vaccination program, have shown to increase immunization rates in these individuals, but in general coverage remains sub-optimal levels [17]. This study was carried out to assess influenza vaccination rate among hospital personnel (healthcare workers and ancillary staff) over a three years period and to assess the impact of health promotion activities over the same periods intended to increase vaccination rate.
and the total potential population to be vaccinated (overall and by professional category). Proportions were compared by Chi-square test and the McNemar test was used to compare vaccination rates on the same professional groups during consecutive campaigns. A significance level of p < 0.05 was established. The association of previous vaccination with vaccination in successive years was assessed by the calculation of odds ratios with the corresponding 95% confidence intervals (95% CI).
2. Methods
3. Results
This cohort-study was carried out in the “12 de Octubre” Hospital, Madrid, Spain, during the 2001–2002, 2002–2003 and 2003–2004 influenza vaccination campaigns. A passive communication strategy, by distributing informative posters throughout the hospital, was used in the 2001–2002 and 2002–2003 seasons. These posters provided information on the disease, vaccines, recommendations, and on timing and sites of vaccination sessions. Additionally, information sheets were sent to the heads of all departments and nursing supervisors for distribution to all personnel. Vaccine was administered free of charge in the Department of Preventive Medicine of the hospital. In the 2003–2004 season, the recommendation was also published in the internal bulletin and web site of the hospital. In addition, a physician and a nurse from the Department of Preventive Medicine visited all hospital departments and offered the influenza vaccination in the workplace. Information on demographics, medical history (including previous influenza vaccination) and professional category was systematically recorded for all vaccinees. The hospital workforce consisted of 1398 nursing assistants, 1758 nurses, 709 staff physicians, 468 resident physicians, and 1321 ancillary staff. The number and distribution of this population did not change during the study period (2001–2004). The Vaccination coverage in each campaign was calculated as the ratio between the number of vaccinees
A total of 2287 hospital workers were vaccinated in the 2003–2004 influenza immunization campaign (vaccination rate of 40.4%) compared with 899 and 1215 in the 2001–2002 and 2002–2003 campaigns (vaccination rates of 15.9 and 21.4%, respectively) (X2 = 97; p < 0.01) (Table 1). The mean age of vaccinees and the age distribution of the professional groups were similar during the three seasons (Table 1). The mean age of the professional groups was similar, with exception of resident physicians that were significantly younger (p < 0.01) (Table 1). All professional groups had a low vaccination coverage rate in the 2001–2002 campaign, ranging from 11.5% in nurses to 16.2% in ancillary staff (X2 = 19; p < 0.01) (Table 1). However, a significant increase over the three seasons was observed among all professional groups (Table 1). The greatest increases were in staff physicians (from 15.2% in 2001–2002 to 59.9% in 2003–2004; X2 = 300; p < 0.01) and resident physicians (from 15.2 to 42.1%, respectively; X2 = 83; p < 0.01). Staff physicians also had a significantly higher vaccination rate than other professional groups (X2 = 288; p < 0.01) in the 2003–2004 campaign. Vaccination rates in nurses and nursing assistants remained below 30% (Table 1) through the study period. In general, persons vaccinated in a previous campaign were more likely to be vaccinated in future campaigns: OR 9.1 (95%CI: 7.8–10.7) and OR 3.9 (95%CI: 3.4–4.4) for 2002–2003 and 2003–2004, respectively.
Table 1 Vaccination rates in the 2001–2002, 2002–2003 and 2003–2004 campaigns Professional group
Vaccinationcampaign
N 2001–2002
2002–2003
P-value
2003–2004
Coverage (%)
Age (S.D.)
Coverage (%)
Age (S.D.)
Coverage (%)
Age (S.D.)
Nursing assistants Nurses Staff physicians Resident physiciansa Ancillary staff
1398 1758 709 468 1321
11.8 11.5 15.2 15.2 16.2
49.8 (9.5) 44.7 (10.3) 51.1 (9.4) 29.6 (4.2) 47.5 (10.4)
15.4 16.7 33.8 29.3 18.5
46.2 (9.9) 43.5 (9.7) 50.0 (9.5) 27.0 (3.6) 45.8 (10.1)
25.4 29.0 59.9 42.1 36.0
46.5 (9.9) 42.9 (9.7) 48.3 (10.0) 26.9 (3.2) 45.9 (9.6)
<0.01 <0.01 <0.01 <0.01 <0.05
Total P-value
5654
15.9 <0.01
45.6 (11.2)
21.4 <0.01
44.2 (11.5)
40.4 <0.01
42.9 (12.0)
<0.01
a
Significantly younger than other professional groups.
J.R. de Juanes et al. / Vaccine 25 (2007) 201–204
203
4. Discussion
References
This study shows that influenza vaccination of healthcare workers in this hospital remains incomplete despite recommendations and health promotion efforts. At the end of the study period (2003–2004 campaign) there was an overall vaccination rate of 41%. This is considerably below the 60% established by the WHO for high-risk groups, and it indicates that healthcare workers are not sufficiently aware of the risk of influenza to themselves and their colleagues and patients as a result of nosocomial transmission [2,16,18–20]. In this study, the vaccination coverage increased significantly in all professional groups over the three seasons studied. This increase was most market in staff physicians who reached a 60% coverage level in the 2003–2004 season. These increases can be mainly attributed to the adoption of vaccination in the workplace. This has previously been shown to be a useful tool for increasing vaccination coverage in some professional groups [16,21]. In addition, it is thought that factors, such as heightened concern over SARS or avian influenza during the same period, may have influenced the increase in the use of influenza vaccine. Persons vaccinated in a previous campaign were between four and nine times more likely to be vaccinated in future seasons. This strong association should be taken into account when vaccination programs in healthcare workers are planned. More than 70% of nursing assistants and nurses were not immunized against influenza in the 2003–2004 season. This confirms previous findings that these professional groups have the lowest vaccination rates, and that in general, nurses are reluctant to receive influenza vaccine [22]. Unfounded concerns about the safety and efficacy of the vaccine, fear of needles and considering themselves not to be at risk are among the reasons for rejecting influenza immunization [18] in this group. Educational programs on the vaccine and the benefits of vaccination will be key tools to improve the acceptance of vaccination by this group of healthcare workers [18,23]. Vaccination is recognized to be the best measure for preventing influenza in both healthcare workers and patients [2]. Immunization of HCWs will protect them, their patients and their colleagues and families, and will reduce the overall burden of influenza disease [2]. Different strategies, adapted to the specific professional characteristics, are required. To move vaccination to the workplace is a key tool to increase the coverage in physicians [18,24]. However, communication and education on the impact of influenza, the overall benefits of vaccination, and the efficacy and safety of the vaccine will be essential for nurses and nursing assistants.
[1] Barker WH. Excess pneumonia and influenza associated hospitalizations during influenza epidemics in the United States. Am J Public Health 1986;76:761–5. [2] Centers for Disease Control and Prevention. Prevention and control of influenza. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 2003;53(RR-06):1– 40. [3] Elorza JM, Campins M, Martinez X, Allupez A, Ferrer E, MendezAguirre M. Vacuna antigripal y personal sanitario: estrategias para aumentar las coberturas en un hospital de tercer nivel. Med Clin (Barc) 2002;119:451–2. [4] Pachucki CT, Pappas SAW, Fuller GF, et al. Influenza A among hospital personnel and patients. Ann Intern Med 1989;149:77– 80. [5] Barlow G, Nathwani D. Nosocomial influenza infection. Lancet 2000;355:1187. [6] Malavaud S, Malavaud B, Sanders K, et al. Nosocomial influenza virus A (H3N2) infection in a solid organ transplant department. Transplantation 2001;72:535–7. [7] Sagrera X, Ginovart G, Raspall F, et al. Outbreak of influenza A virus infection in neonatal intensive care units. Pediatr Infect Dis J 2002;21:196–200. [8] Arroyo JC, Postic B, Brown A, et al. Influenza A/Philipines/2/82 outbreak in a nursing home: limitations of influenza vaccination in the aged. Am J Infect Control 1984;12:329–34. [9] Christie RW, Marquis LL. Immunization roulette: influenza occurrence in five nursing homes. Am J Infect Control 1985;13:174– 7. [10] Outbreak of influenza A in nursing home—New York, December 1991–January 1992. MMWR Mor Mortal Wkly Rep 1992;41:129– 131. [11] Potter J, Scott DJ, Roberts MA, et al. Influenza vaccination of healthcare workers in long-term-care hospitals reduces mortality of elderly patients. J Infect Dis 1997;175:1–6. [12] Carman WF, Elder AG, Wallace LA, et al. Effects of influenza vaccination of health-care workers on mortality of elderly people in long-term care: a randomized controlled trial. Lancet 2000;355: 93–7. [13] Slinger R, Dennis P. Nosocomial influenza at a Canadian Pediatric Hospital from 1995 to 1999: opportunities for prevention. Infect Control Hosp Epidemiol 2002;23(10):627–9. [14] Weingarten S, Riedinger M, Bolton LB, et al. Barriers to influenza vaccine acceptance. Am J Infect Control 1989;17:202– 7. [15] Nichol KL, Hauge M. influenza vaccination of healthcare workers. Infect Control Hosp Epidemiol 1997;18:189–94. [16] Christian MA. Influenza and hepatitis B vaccine acceptance: a survey of healthcare workers. Am J Infect Control 1991;19:177– 84. [17] Adal KA, Flowers RH, Anglim AM, et al. Prevention of nosocomial influenza. Infect Control Hosp Epidemiol 1996;17:641– 8. [18] Martinello RA, Jones L, Topal JE. Correlations between Healthcare Workers’Knowledge of influenza vaccine and vaccine receipt. Infect Control Hosp Epidemiol 2003;24(11):845–7. [19] Rehmet S, Ammon A, Plaff G, Bocter N, Petersen LR. Cross-sectional study on influenza vaccination, Germany, 1999–2000. Emerg Infect Dis 2002;8(12):1442–7. [20] Doebbeling BN, Edmond MB, Davis CS, Woodin JR, Zeitler RR. Influenza vaccination of Health Care Workers: evaluation of factors that are important in acceptance. Prev Med 1997;26:68– 77. [21] Fedson DS. Influenza vaccinations of medical residents at the University of Virginia: 1986 to 1994. Infect Control Hosp Epidemiol 1996;17(7):431–3.
Acknowledgements We would like to thank Dr. Michael Watson for his review and valuable suggestions.
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J.R. de Juanes et al. / Vaccine 25 (2007) 201–204
[22] Harbarth S, Seigrist CA, Schira JC, Wunderli W, Pittet D. Influenza immunization: improving compliance of healthcare workers. Infect Control Hosp Epidemiol 1998;19(5):337–42. [23] Beguin C, Boland B, Ninane J. Health Care Workers: vectors of influenza virus? Low vaccination rate among hospital health care workers. Am J Med Qual 1998;13(4):223–7.
[24] Steiner MA, Vermeulen LC, Mullahy J, Hayney MS. Factors influencing decisions regarding influenza vaccination and treatment: a survey of healthcare workers. Infect Control Hosp Epidemiol 2002;23(10):625–7.
Influenza vaccination coverage among hospital personnel over three consecutive vaccination campaigns (2001–2002 to 2003–2004) J.R. de Juanes a,∗ , A. Garc´ıa de Codes a , M.P. Arrazola a , F. Ja´en a , M.I. Sanz a , A. Gonz´alez b a
Preventive Medicine Service, Jefe de Servicio de Medicina Preventiva, Hospital “12 de Octubre”, Carretera de Andaluc´ıa Km 5, 28041 Madrid, Spain b Medical Department, Sanofi Pasteur MSD, Madrid, Spain Received 4 September 2005; received in revised form 8 October 2005; accepted 11 October 2005 Available online 1 December 2005
Abstract This study was carried out to assess influenza vaccination coverage among hospital personnel and the impact of health promotion campaigns, within the hospital, designed to increase vaccination coverage over three consecutive vaccination campaigns (2001–2002 to 2003–2004). The health promotion tool used in the 2001–2002 and 2002–2003 were informative posters distributed throughout the hospital. In the 2003–2004 season, the recommendation was also published in the internal bulletin and Web site of the hospital. In addition, a physician and a nurse from the Department of Preventive Medicine visited all departments offering vaccination in the work place. The overall vaccination coverage in the 2001–2002 campaign was 16% with coverage of 11.5% in nurses and 15% in physicians. In the 2002–2003 and 2003–2004 campaigns the overall vaccination coverage was 21% and 40%, respectively (p < 0.01). Staff physicians and resident physicians reached 60 and 42% coverage rates in the 2003–2004 campaign, but coverage in nurses and nursing assistant remained around 30% (p < 0.01). In summary, influenza vaccination coverage among hospital based healthcare personnel increased significantly during the last three seasons, however, it still remains low despite active attempts at promoting influenza vaccination. © 2006 Published by Elsevier Ltd. Keywords: Health-care workers; Influenza; Vaccination
1. Introduction Influenza is among the leading causes of respiratory infection and it represents a significant public health burden. Elderly people and patients with underlying health conditions are at increased risk of complications of influenza, including hospitalization and death [1]. During epidemics, the hospitalization rate for the elderly and people with chronic health problems may increase two to five-fold compared with nonepidemic periods [1]. Healthcare workers (HCWs) who are clinically or sub-clinically infected can transmit influenza virus to persons at risk for complications of influenza [2]. For ∗ Corresponding author. Tel.: +34 1 3908026; fax: +34 91 3908582/4018622. E-mail address: [email protected] (J.R. de Juanes).
0264-410X/$ – see front matter © 2006 Published by Elsevier Ltd. doi:10.1016/j.vaccine.2005.10.057
this reason, annual vaccination against influenza is recommended for HCWs [2]. However, despite recommendations some studies show that HCWs have low rates of acceptance of vaccination [2,3]. Acquisition of influenza by HCWs may cause absenteeism and significant disruption of health care, but also serves as the source for nosocomial transmission to patients and hospital staff [4–7]. During epidemics, attack rates ranging from 25 to 80% are observed among both patients and staff [8–10]. However, patients in facilities in which more than 60% of the healthcare personnel were vaccinated experienced less influenza related morbidity and mortality than patients in centers whose personnel were not vaccinated [11–13]. This suggests that Health care institutions should offer and encourage the use of influenza vaccine among HCWs. However, HCWs cite a number of barriers to influenza vaccination. These barriers include incon-
202
J.R. de Juanes et al. / Vaccine 25 (2007) 201–204
venient vaccine administration or concerns about potential side effects [14–16]. Some interventions, such as the use of a mobile cart vaccination program, have shown to increase immunization rates in these individuals, but in general coverage remains sub-optimal levels [17]. This study was carried out to assess influenza vaccination rate among hospital personnel (healthcare workers and ancillary staff) over a three years period and to assess the impact of health promotion activities over the same periods intended to increase vaccination rate.
and the total potential population to be vaccinated (overall and by professional category). Proportions were compared by Chi-square test and the McNemar test was used to compare vaccination rates on the same professional groups during consecutive campaigns. A significance level of p < 0.05 was established. The association of previous vaccination with vaccination in successive years was assessed by the calculation of odds ratios with the corresponding 95% confidence intervals (95% CI).
2. Methods
3. Results
This cohort-study was carried out in the “12 de Octubre” Hospital, Madrid, Spain, during the 2001–2002, 2002–2003 and 2003–2004 influenza vaccination campaigns. A passive communication strategy, by distributing informative posters throughout the hospital, was used in the 2001–2002 and 2002–2003 seasons. These posters provided information on the disease, vaccines, recommendations, and on timing and sites of vaccination sessions. Additionally, information sheets were sent to the heads of all departments and nursing supervisors for distribution to all personnel. Vaccine was administered free of charge in the Department of Preventive Medicine of the hospital. In the 2003–2004 season, the recommendation was also published in the internal bulletin and web site of the hospital. In addition, a physician and a nurse from the Department of Preventive Medicine visited all hospital departments and offered the influenza vaccination in the workplace. Information on demographics, medical history (including previous influenza vaccination) and professional category was systematically recorded for all vaccinees. The hospital workforce consisted of 1398 nursing assistants, 1758 nurses, 709 staff physicians, 468 resident physicians, and 1321 ancillary staff. The number and distribution of this population did not change during the study period (2001–2004). The Vaccination coverage in each campaign was calculated as the ratio between the number of vaccinees
A total of 2287 hospital workers were vaccinated in the 2003–2004 influenza immunization campaign (vaccination rate of 40.4%) compared with 899 and 1215 in the 2001–2002 and 2002–2003 campaigns (vaccination rates of 15.9 and 21.4%, respectively) (X2 = 97; p < 0.01) (Table 1). The mean age of vaccinees and the age distribution of the professional groups were similar during the three seasons (Table 1). The mean age of the professional groups was similar, with exception of resident physicians that were significantly younger (p < 0.01) (Table 1). All professional groups had a low vaccination coverage rate in the 2001–2002 campaign, ranging from 11.5% in nurses to 16.2% in ancillary staff (X2 = 19; p < 0.01) (Table 1). However, a significant increase over the three seasons was observed among all professional groups (Table 1). The greatest increases were in staff physicians (from 15.2% in 2001–2002 to 59.9% in 2003–2004; X2 = 300; p < 0.01) and resident physicians (from 15.2 to 42.1%, respectively; X2 = 83; p < 0.01). Staff physicians also had a significantly higher vaccination rate than other professional groups (X2 = 288; p < 0.01) in the 2003–2004 campaign. Vaccination rates in nurses and nursing assistants remained below 30% (Table 1) through the study period. In general, persons vaccinated in a previous campaign were more likely to be vaccinated in future campaigns: OR 9.1 (95%CI: 7.8–10.7) and OR 3.9 (95%CI: 3.4–4.4) for 2002–2003 and 2003–2004, respectively.
Table 1 Vaccination rates in the 2001–2002, 2002–2003 and 2003–2004 campaigns Professional group
Vaccinationcampaign
N 2001–2002
2002–2003
P-value
2003–2004
Coverage (%)
Age (S.D.)
Coverage (%)
Age (S.D.)
Coverage (%)
Age (S.D.)
Nursing assistants Nurses Staff physicians Resident physiciansa Ancillary staff
1398 1758 709 468 1321
11.8 11.5 15.2 15.2 16.2
49.8 (9.5) 44.7 (10.3) 51.1 (9.4) 29.6 (4.2) 47.5 (10.4)
15.4 16.7 33.8 29.3 18.5
46.2 (9.9) 43.5 (9.7) 50.0 (9.5) 27.0 (3.6) 45.8 (10.1)
25.4 29.0 59.9 42.1 36.0
46.5 (9.9) 42.9 (9.7) 48.3 (10.0) 26.9 (3.2) 45.9 (9.6)
<0.01 <0.01 <0.01 <0.01 <0.05
Total P-value
5654
15.9 <0.01
45.6 (11.2)
21.4 <0.01
44.2 (11.5)
40.4 <0.01
42.9 (12.0)
<0.01
a
Significantly younger than other professional groups.
J.R. de Juanes et al. / Vaccine 25 (2007) 201–204
203
4. Discussion
References
This study shows that influenza vaccination of healthcare workers in this hospital remains incomplete despite recommendations and health promotion efforts. At the end of the study period (2003–2004 campaign) there was an overall vaccination rate of 41%. This is considerably below the 60% established by the WHO for high-risk groups, and it indicates that healthcare workers are not sufficiently aware of the risk of influenza to themselves and their colleagues and patients as a result of nosocomial transmission [2,16,18–20]. In this study, the vaccination coverage increased significantly in all professional groups over the three seasons studied. This increase was most market in staff physicians who reached a 60% coverage level in the 2003–2004 season. These increases can be mainly attributed to the adoption of vaccination in the workplace. This has previously been shown to be a useful tool for increasing vaccination coverage in some professional groups [16,21]. In addition, it is thought that factors, such as heightened concern over SARS or avian influenza during the same period, may have influenced the increase in the use of influenza vaccine. Persons vaccinated in a previous campaign were between four and nine times more likely to be vaccinated in future seasons. This strong association should be taken into account when vaccination programs in healthcare workers are planned. More than 70% of nursing assistants and nurses were not immunized against influenza in the 2003–2004 season. This confirms previous findings that these professional groups have the lowest vaccination rates, and that in general, nurses are reluctant to receive influenza vaccine [22]. Unfounded concerns about the safety and efficacy of the vaccine, fear of needles and considering themselves not to be at risk are among the reasons for rejecting influenza immunization [18] in this group. Educational programs on the vaccine and the benefits of vaccination will be key tools to improve the acceptance of vaccination by this group of healthcare workers [18,23]. Vaccination is recognized to be the best measure for preventing influenza in both healthcare workers and patients [2]. Immunization of HCWs will protect them, their patients and their colleagues and families, and will reduce the overall burden of influenza disease [2]. Different strategies, adapted to the specific professional characteristics, are required. To move vaccination to the workplace is a key tool to increase the coverage in physicians [18,24]. However, communication and education on the impact of influenza, the overall benefits of vaccination, and the efficacy and safety of the vaccine will be essential for nurses and nursing assistants.
[1] Barker WH. Excess pneumonia and influenza associated hospitalizations during influenza epidemics in the United States. Am J Public Health 1986;76:761–5. [2] Centers for Disease Control and Prevention. Prevention and control of influenza. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 2003;53(RR-06):1– 40. [3] Elorza JM, Campins M, Martinez X, Allupez A, Ferrer E, MendezAguirre M. Vacuna antigripal y personal sanitario: estrategias para aumentar las coberturas en un hospital de tercer nivel. Med Clin (Barc) 2002;119:451–2. [4] Pachucki CT, Pappas SAW, Fuller GF, et al. Influenza A among hospital personnel and patients. Ann Intern Med 1989;149:77– 80. [5] Barlow G, Nathwani D. Nosocomial influenza infection. Lancet 2000;355:1187. [6] Malavaud S, Malavaud B, Sanders K, et al. Nosocomial influenza virus A (H3N2) infection in a solid organ transplant department. Transplantation 2001;72:535–7. [7] Sagrera X, Ginovart G, Raspall F, et al. Outbreak of influenza A virus infection in neonatal intensive care units. Pediatr Infect Dis J 2002;21:196–200. [8] Arroyo JC, Postic B, Brown A, et al. Influenza A/Philipines/2/82 outbreak in a nursing home: limitations of influenza vaccination in the aged. Am J Infect Control 1984;12:329–34. [9] Christie RW, Marquis LL. Immunization roulette: influenza occurrence in five nursing homes. Am J Infect Control 1985;13:174– 7. [10] Outbreak of influenza A in nursing home—New York, December 1991–January 1992. MMWR Mor Mortal Wkly Rep 1992;41:129– 131. [11] Potter J, Scott DJ, Roberts MA, et al. Influenza vaccination of healthcare workers in long-term-care hospitals reduces mortality of elderly patients. J Infect Dis 1997;175:1–6. [12] Carman WF, Elder AG, Wallace LA, et al. Effects of influenza vaccination of health-care workers on mortality of elderly people in long-term care: a randomized controlled trial. Lancet 2000;355: 93–7. [13] Slinger R, Dennis P. Nosocomial influenza at a Canadian Pediatric Hospital from 1995 to 1999: opportunities for prevention. Infect Control Hosp Epidemiol 2002;23(10):627–9. [14] Weingarten S, Riedinger M, Bolton LB, et al. Barriers to influenza vaccine acceptance. Am J Infect Control 1989;17:202– 7. [15] Nichol KL, Hauge M. influenza vaccination of healthcare workers. Infect Control Hosp Epidemiol 1997;18:189–94. [16] Christian MA. Influenza and hepatitis B vaccine acceptance: a survey of healthcare workers. Am J Infect Control 1991;19:177– 84. [17] Adal KA, Flowers RH, Anglim AM, et al. Prevention of nosocomial influenza. Infect Control Hosp Epidemiol 1996;17:641– 8. [18] Martinello RA, Jones L, Topal JE. Correlations between Healthcare Workers’Knowledge of influenza vaccine and vaccine receipt. Infect Control Hosp Epidemiol 2003;24(11):845–7. [19] Rehmet S, Ammon A, Plaff G, Bocter N, Petersen LR. Cross-sectional study on influenza vaccination, Germany, 1999–2000. Emerg Infect Dis 2002;8(12):1442–7. [20] Doebbeling BN, Edmond MB, Davis CS, Woodin JR, Zeitler RR. Influenza vaccination of Health Care Workers: evaluation of factors that are important in acceptance. Prev Med 1997;26:68– 77. [21] Fedson DS. Influenza vaccinations of medical residents at the University of Virginia: 1986 to 1994. Infect Control Hosp Epidemiol 1996;17(7):431–3.
Acknowledgements We would like to thank Dr. Michael Watson for his review and valuable suggestions.
204
J.R. de Juanes et al. / Vaccine 25 (2007) 201–204
[22] Harbarth S, Seigrist CA, Schira JC, Wunderli W, Pittet D. Influenza immunization: improving compliance of healthcare workers. Infect Control Hosp Epidemiol 1998;19(5):337–42. [23] Beguin C, Boland B, Ninane J. Health Care Workers: vectors of influenza virus? Low vaccination rate among hospital health care workers. Am J Med Qual 1998;13(4):223–7.
[24] Steiner MA, Vermeulen LC, Mullahy J, Hayney MS. Factors influencing decisions regarding influenza vaccination and treatment: a survey of healthcare workers. Infect Control Hosp Epidemiol 2002;23(10):625–7.