Influenza outbreak detection and control measures in nursing homes in the United States

OBJECTIVE: To evaluate the use of influenza vaccine, rapid influenza testing, and influenza antiviral medication in nursing homes in the US to prevent and control outbreaks. METHODS: Survey questionnaires were sent to 1017 randomly selected nursing homes in nine states. Information was collected on influenza prevention, detection and control practices, and on outbreaks during three influenza seasons (1995-1998). RESULTS: The survey response rate was 78%. Influenza vaccine was offered to residents and staff by 99% and 86%, respectively, of nursing homes. Among nursing homes offering the influenza vaccine, the average vaccination rate was 83% for residents and 46% for staff. Sixty-seven percent of the nursing homes reported having access to laboratories with rapid antigen testing capabilities, and 19% reported having a written policy for the use of influenza antiviral medications for outbreak control. Nursing homes from New York, where organized education programs on influenza detection and control have been conducted for many years, were more likely to have reported a suspected or laboratory-confirmed influenza outbreak (51% vs 10%, P = .01), to have access to rapid antigen testing for influenza (92% vs 63%, P = .01), and to use antivirals for prophylaxis and treatment of influenza A for their nursing home residents (94% vs 55%, P = .01) compared with nursing homes from the other eight states. CONCLUSIONS: Influenza outbreaks among nursing home residents can lead to substantial morbidity and mortality when prevention measures are not rapidly instituted. However, many nursing homes in this survey were neither prepared to detect nor to control influenza A outbreaks. Targeted, sustained educational efforts can improve the detection and control of outbreaks in nursing homes.     

Efficacy of Influenza Vaccine in Elderly Persons in Welfare Nursing Homes: Reduction in Risks of Mortality and Morbidity During an Influenza A (H3N2) Epidemic

BACKGROUND: The effect of influenza vaccination on the occurrence and severity of influenza virus infection in a population residing in nursing homes was studied through a program by the Osaka Prefectural Government, which is the first and official support for influenza vaccination of the elderly population during an influenza A (H3N2) epidemic in JAPAN: METHODS: A cohort study located in the Osaka Prefecture, Japan, followed the outcomes of elderly nursing home residents who received influenza vaccinations (n = 10,739) in comparison with control subjects who did not receive influenza vaccinations (n = 11,723) and monitored clinically the onset of serious morbidity and mortality of influenza illness. Subjects were 22,462 persons older than 65 years who resided in 301 welfare nursing homes in the Osaka Prefecture, Japan during an influenza A (H3N2) epidemic in 1998 to 1999. RESULTS: Of 22,462 individuals living in 301 nursing homes, 10,739 received either one dose (2027 subjects) or two doses (8712 subjects) of inactivated, subunit trivalent influenza vaccine. Through the period from November 1998 to March 1999, there were 950 cases of influenza infection diagnosed clinically with cases by virus isolation and/or serology. There were statistically significantly fewer clinical cases of influenza, hospital admissions due to severe infection, and deaths due to influenza in the vaccinated cohort (256 cases, 32 hospital admissions, and one death) compared with the unvaccinated controls (694 cases, 150 hospital admissions, and five deaths). Vaccination was equally effective in those who received one dose of vaccine as in those who received two doses. No serious adverse reactions to vaccination were recorded. Thus, influenza vaccination is safe and effective in this population and should be an integral part of the routine care of persons aged 65 years and older residing in nursing homes. CONCLUSIONS: This study provides an analysis of the clinical efficacy of influenza vaccination in a large cohort of nursing home residents in JAPAN: Annual influenza vaccine administration requires the attention of all nursing home attendants, physicians, and public health organizations.     

Effect of Influenza Vaccination of Nursing Home Staff on Mortality of Residents: A Cluster-Randomized Trial

OBJECTIVES: To evaluate the effect of staff influenza vaccination on all-cause mortality in nursing home residents.
DESIGN: Pair-matched cluster-randomized trial.
SETTING: Forty nursing homes matched for size, staff vaccination coverage during the previous season, and resident disability index.
PARTICIPANTS: All persons aged 60 and older residing in the nursing homes.
INTERVENTION: Influenza vaccine was administered to volunteer staff after a face-to-face interview. No intervention took place in control nursing homes.
MEASUREMENTS: The primary endpoint was total mortality rate in residents from 2 weeks before to 2 weeks after the influenza epidemic in the community. Secondary endpoints were rates of hospitalization and influenza-like illness (ILI) in residents and sick leave from work in staff.
RESULTS: Staff influenza vaccination rates were 69.9% in the vaccination arm versus 31.8% in the control arm. Primary unadjusted analysis did not show significantly lower mortality in residents in the vaccination arm (odds ratio=0.86, P =.08), although multivariate-adjusted analysis showed 20% lower mortality ( P =.02), and a strong correlation was observed between staff vaccination coverage and all-cause mortality in residents (correlation coefficient=−0.42, P =.007). In the vaccination arm, significantly lower resident hospitalization rates were not observed, but ILI in residents was 31% lower ( P =.007), and sick leave from work in staff was 42% lower ( P =.03).
CONCLUSION: These results support influenza vaccination of staff caring for institutionalized elderly people.     

Immunogenicity and safety of three commercial influenza vaccines in institutionalized elderly

Influenza is a leading cause of morbidity and mortality in elderly people. This prospective, observed-blind, randomized, multicenter trial compares the immunogenicity and safety of three influenza vaccines in a sample of 635 elderly residents of four nursing homes in Milano (Italy). All vaccines were well tolerated: no serious adverse events were recorded, and a small number (9 subjects) of local and systemic reactions were observed. Twenty-nine oropharyngeal swabs were taken during the season from ILI (influenza-like illness) patients, none of whom was positive for influenza and other respiratory viruses. Immunogenicity was evaluated in a subgroup of 111 subjects with blood samples obtained just before vaccination and after 4 and 12 weeks. The adjuvanted vaccines, subunit vaccine with MF59 (a-SUV) and virosome subunit vaccine (v-SUV), induced a higher antibody response than whole virus vaccine (WVV). There was no significant difference between groups that received a-SUV and v-SUV, but the a-SUV group had higher values of geometric mean titres than the v-SUV group for H1N1 and B influenza strains. These findings suggest that influenza vaccination is effective, and they underscore the importance of vaccination programs for institutionalized elderly. Further studies are needed to compare other adjuvanted vaccines in order to define their different properties.     

Antivirals and the control of influenza outbreaks.

During annual influenza epidemics, outbreaks of influenza in closed institutions are common. Among healthy children or young adults, such outbreaks are uncommonly associated with serious morbidity or mortality; however, in hospitals and nursing homes, attack rates as high as 60% and case-fatality rates as high as 50% have been reported. Annual influenza vaccination of both patients or residents and hospital and nursing home staff has had a substantial impact on mortality and has reduced the number of outbreaks. Nonpharmacologic interventions (e.g., handwashing and contact isolation of case patients) may reduce the spread of influenza, although evidence for their efficacy is lacking. Nonetheless, long-term care facilities for the elderly population with high vaccination rates and better-than-average infection-control programs have a 25%-50% chance of experiencing an influenza outbreak each year, with an expected resident attack rate of 35%-40%. Thus, antiviral drugs have been increasingly used to mitigate the impact of influenza outbreaks. There are 2 classes of antiviral drugs that are active against influenza: adamantanes and neuraminidase inhibitors. Drugs of the 2 classes appear to be equally effective for the treatment and prophylaxis of susceptible influenza A virus strains. However, adamantanes are not active against influenza B virus, and an increasing proportion of influenza A isolates are resistant to adamantanes. Adamantanes are associated with higher rates of adverse events than are neuraminidase inhibitors. There is substantial evidence that antiviral prophylaxis is effective in terminating outbreaks of seasonal influenza in closed institutions. If stockpiles are adequate, antiviral drugs are likely to be even more important in mitigating the impact of influenza transmission in health care institutions during the next influenza pandemic.     

Effectiveness of Influenza Vaccination for Individuals with Chronic Obstructive Pulmonary Disease (COPD) in Low- and Middle-Income Countries

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death globally. In addition to the mortality associated with it, people with COPD experience significant morbidity, making this set of conditions a major public health concern. Infections caused by influenza virus are a preventable cause of morbidity and vaccination has been shown to be effective. The evidence of their benefit in persons with COPD mainly comes from high-income countries where influenza vaccination is used in routine practice, but little is known about the effectiveness, cost-effectiveness, and scalability of vaccination in low- and middle-income countries. We therefore systematically reviewed and present evidence related to vaccination against influenza in persons with COPD with a special focus on studies from low- and middle-income countries (LMICs). Available data from 19 studies suggest that the use of influenza vaccine in persons with COPD is beneficial, cost-effective, and may be relevant for low- and middle-income countries. Wider implementation of this intervention needs to take into account the health care delivery systems of LMICs and use of prevalent viral strains in vaccines to be most cost effective.     

Influenza vaccination in community-dwelling elderly: impact on mortality and influenza-associated morbidity

BACKGROUND: Influenza-related morbidity and mortality have been extensively studied with hospital and reimbursement data. However, little is known about the effectiveness of the annual vaccination programs in generally healthy community-dwelling elderly. The objective of our study was to investigate the effectiveness of influenza vaccination in community-dwelling elderly during the 1996 to 1997 influenza epidemic. METHODS: We performed a population-based cohort study using the computerized Integrated Primary Care Information database in the Netherlands. Subjects who were 65 years and older in 1996 with a permanent status in a practice in the source population were considered eligible for study participation. Two cohorts were defined on the basis of vaccination status. We estimated and compared all-cause mortality, pneumonia, and clinical influenza infection rates between the cohorts. RESULTS: Influenza vaccination was associated with a significant reduction of morbidity and mortality in vaccinated elderly (relative risk [RR], 0.72; 95% confidence interval [CI], 0.60-0.87). Influenza infections decreased significantly in the vaccinated population (RR, 0.48; 95% CI, 0.26-0.91). Mortality was reduced significantly in elderly with comorbidity (RR, 0.67; 95% CI, 0.48-0.94). The risk reduction for pneumonia was nonsignificant (RR, 0.77; 95% CI, 0.55-1.07) but was temporally related to the peak influenza activity. CONCLUSIONS: In this study, influenza vaccination was associated with decreased mortality and influenza infections in community-dwelling elderly. Our results indicate that, in a season of mild influenza activity and good antigenic match between vaccine strains and circulating strains, influenza vaccination reduced mortality in the vaccinated population. Our data support an annual vaccination strategy for all community-dwelling elderly.     

Influenza A pneumonitis in a patient infected with the human immunodeficiency virus (HIV)

Influenza A results in considerable morbidity, mortality and economic costs. Although immunoprophylaxis and chemoprophylaxis are targeted toward high-risk groups, persons with human immunodeficiency virus (HIV) infection have not been widely recognized as being at increased risk of influenza infection. We report a case of influenza A pneumonitis in a patient infected with HIV. The literature on influenza immunization of HIV-infected patients is reviewed and the implications for public health are discussed. Consideration should be given to influenza immunization and chemoprophylaxis in this enlarging population. Further investigation of the pathogenesis and epidemiology of influenza in HIV-infected patients is warranted.     

Do Vaccination Strategies Implemented by Nursing Homes Narrow the Racial Gap in Receipt of Influenza Vaccination in the United States?

OBJECTIVES: To determine whether the racial inequity between African Americans and Caucasians in receipt of influenza vaccine is narrower in residents of nursing homes with facility‐wide vaccination strategies than in residents of facilities without vaccination strategies. DESIGN: Secondary data analysis using the National Nursing Home Survey 2004, a nationally representative survey. SETTING: One thousand one hundred seventy‐four participating nursing homes sampled systematically with probability proportional to bed size. PARTICIPANTS: Thirteen thousand five hundred seven randomly sampled residents of nursing homes between August and December 2004. MEASUREMENTS: Receipt of influenza vaccine within the last year. Logistic regression was used to examine the relationship between facility‐level influenza immunization strategy and racial inequity in receipt of vaccination, adjusted for characteristics at the resident, facility, state, and regional levels. RESULTS: Overall in the Untied States, vaccination coverage was higher for Caucasian and African‐American residents; the racial vaccination gaps were smaller (<6 percentage points) and nonsignificant in residents of homes with standing orders for influenza vaccinations (P=.14), verbal consent allowed for vaccinations(P=.39), and routine review of facility‐wide vaccination rates (P=.61) than for residents of homes without these strategies. The racial vaccination gap in residents of homes without these strategies were two to three times as high (P=.009, P=.002, and P=.002, respectively). CONCLUSION: The presence of several immunization strategies in nursing homes is associated with higher vaccination coverage for Caucasian and African‐American residents, narrowing the national vaccination racial gap.     

Long-standing influenza vaccination policy is in accord with individual self-interest but not with the utilitarian optimum

Influenza vaccination is vital for reducing infection-mediated morbidity and mortality. To maximize effectiveness, vaccination programs must anticipate the effects of public perceptions and attitudes on voluntary adherence. A vaccine allocation strategy that is optimal for the population is not necessarily optimal for an individual. For epidemic influenza, the elderly have the greatest risk of influenza mortality, yet children are responsible for most of the transmission. The long-standing recommendations of the Centers for Disease Control follow the dictates of individual self-interest and prioritize the elderly for vaccination. However, preferentially vaccinating children may dramatically reduce community-wide influenza transmission. A potential obstacle to this is that the personal utility of vaccination is lower for children than it is for the elderly. We parameterize an epidemiological game-theoretic model of influenza vaccination with questionnaire data on actual perceptions of influenza and its vaccine to compare Nash equilibria vaccination strategies driven by self-interest with utilitarian strategies for both epidemic and pandemic influenza. Our results reveal possible strategies to bring Nash and utilitarian vaccination levels into alignment.     

Geriatric patient outcomes and costs in three settings: nursing home, foster family, and own home

Forty-nine matched triads of geriatric patients were compared after three months in their respective placement settings: nursing homes, geriatric foster homes, and own homes with supportive services. Compared to similarly disabled patients in nursing homes, patients in the two community settings made greater improvements in self-care skills and mobility, expressed greater well-being, had similar types and amounts of morbidity, and entailed lower costs. The results support the expansion of home and community-based services as alternatives to institutional care for a substantial number of geriatric patients.     

Influenza vaccine in the elderly and chronic obstructive pulmonary disease

Influenza viruses are RNA viruses that are a major determinant of morbidity and mortality caused by respiratory disease. Influenza is highly contagious and has caused epidemics and pandemics for centuries. Most influenza infections are selflimited, but lower respiratory tract and cardiac complications can result in increases in hospitalizations and deaths. The recommended composition of influenza vaccine is updated annually in order to provide a vaccine that is antigenically well matched with the new influenza virus strains that are expected to cause epidemics. Influenza vaccination significantly reduces mortality; however, approximately one third of elderly Americans are not immunized annually. The nation’s goal is to increase the influenza vaccination rate among the elderly to 90%. Vaccination is the most effective measure for reducing the impact of influenza and is a cost-effective preventive health intervention for the elderly and individuals with chronic obstructive pulmonary disease.     

Economic evaluation of oseltamivir phosphate for postexposure prophylaxis of influenza in long-term care facilities

OBJECTIVES: To compare the cost-effectiveness of oseltamivir postexposure prophylaxis during influenza A outbreaks with that of amantadine postexposure prophylaxis or no postexposure prophylaxis in long-term care facilities (LTCFs). DESIGN: Cost-effectiveness analysis based on decision analytic model from a government-payer perspective. SETTING: A Canadian LTCF, with high staff vaccination, at the beginning of influenza season. PARTICIPANTS: Elderly, influenza-vaccinated patients living in a Canadian LTCF. MEASUREMENTS: Incremental costs (or savings) per influenza-like illness case avoided compared with usual care. RESULTS: From a government-payer perspective, this analysis showed that oseltamivir was a dominant strategy because it was associated with the fewest influenza-like illness cases, with cost savings of $1,249 per 100 patients in 2001 Canadian dollars compared with amantadine and $3,357 per 100 patients compared with no prophylaxis. Costs for amantadine dose calculation and hospitalization for adverse events contributed to amantadine being a more-expensive prophylaxis strategy than oseltamivir. Both prophylaxis strategies were more cost-effective than no prophylaxis. CONCLUSION: Despite high influenza vaccination rates, influenza outbreaks continue to emerge in LTCFs, necessitating cost-effective measures to further limit the spread of influenza and related complications. Although amantadine has a lower acquisition cost than oseltamivir, it is associated with more adverse events, lower efficacy, and individualized dosing requirements, leading to higher overall costs and more influenza-like illness cases than oseltamivir. Therefore the use of oseltamivir postexposure prophylaxis is more cost-effective than the current standard of care with amantadine prophylaxis or no prophylaxis.     

Hospitalizations and deaths due to respiratory illnesses during influenza seasons: a comparison of community residents,senior housing residents,and nursing home residents

BACKGROUND: Although research indicates that influenza is a major cause of morbidity and mortality among older adults, few studies have tried to identify which seniors are particularly at risk of experiencing complications of influenza. The purpose of this study was to compare hospitalizations and deaths due to respiratory illnesses during influenza seasons among seniors (aged 65+) living in the community, senior residences (apartments reserved for seniors), and nursing homes. METHODS: Using administrative data, all hospital admissions and deaths due to respiratory illnesses (pneumonia and influenza, chronic lung disease, and acute respiratory diseases) were identified for all individuals aged 65 and older living in Winnipeg, Canada (approximately 88,000 individuals) during four influenza seasons (1995-1996 to 1998-1999). RESULTS: Hospitalization and death rates for respiratory illnesses increased significantly during influenza seasons, compared to fall periods (e.g., 42.7 vs 25.2 hospitalizations per 1000 population aged 80 and older). Moreover, hospitalization rates for pneumonia and influenza, chronic lung disease, and acute respiratory diseases were higher among individuals living in senior residences (42.5 per 1000 for all respiratory illnesses combined) than their counterparts living in the community (22.8 per 1000). Furthermore, deaths due to pneumonia and influenza and chronic lung disease were higher among senior housing residents (4.2 per 1000) than community residents (2.6 per 1000) and were particularly high among nursing home residents (52.1 per 1000). CONCLUSIONS: Individuals living in seniors residences are at increased risk of being hospitalized for and dying of respiratory illnesses during influenza seasons. Given that influenza vaccination is currently the best method to reduce influenza-associated illnesses among seniors, this suggests that influenza vaccination strategies should be targeted at this population.     

Treatment of an influenza A outbreak in a teaching nursing home. Effectiveness of a protocol for prevention and control

The safety and efficacy of current ACIP guidelines for the prevention and control of influenza in nursing home populations are uncertain. An outbreak of influenza A/Sichuan (H3N2) in a teaching nursing home during 1988 gave us the opportunity to evaluate the effectiveness of an influenza vaccination and amantadine prophylaxis protocol. Over 13 days, 12 of 60 residents developed influenza. Prior influenza vaccination had been given to 94% of the residents. Protection from infection occurred in those tested who had antibody levels greater than or equal to 1:16 to the A/Leningrad (H3N2) antigen contained in the standard 1987-88 trivalent vaccine. However, five of 17 vaccinated residents who were tested had antibody levels less than or equal to 1:16 at the start of the outbreak. Amantadine (less than or equal to 100 mg/day) was given to all but one resident starting on the third day of the outbreak, and to employees starting on the sixth day of the outbreaks. Seven residents developed illness after the start of amantadine, although amantadine appeared to ameliorate their symptoms. Although amantadine was generally well tolerated by residents, employees receiving amantadine identified a high incidence of side effects and only 44% of employees took at least 70% of the prescribed amantadine. In our opinion, early detection and protocol-directed intervention probably abated a more severe influenza outbreak. Therefore we support existing recommendations that formal nursing home policies be established to ensure that residents and employees receive annual influenza vaccine and that chemoprophylaxis be used when outbreaks of influenza A are suspected.     

Theory and models for planning and evaluating institutional influenza prevention and control programs

BACKGROUND: Low rates of staff influenza vaccine coverage occur in many health care facilities. Many programs do not offer vaccination to physicians or to volunteers, and some programs do not measure coverage or do so only for a subset of staff. The use of theory in planning and evaluation may prevent these problems and lead to more effective programs. METHOD: We discuss the use of theory in the planning and evaluation of health programs and demonstrate how it can be used for the evaluation and planning of a hospital or nursing home influenza control program. RESULTS: The application of theory required explicit statement of the goals of the program and examination of the assumptions underlying potential program activities. This indicated that staff should probably be considered as employees, volunteers, physicians, and contractors of the facility. It also directed attention to evidence-based strategies for increasing vaccination rates. CONCLUSION: The application of a program planning model to a problem of institutional influenza prevention may prevent planners from excluding important target populations and failing to monitor the important indicators of program success.     

Hip fracture incidence in the elderly in Austria: An epidemiological study covering the years 1994 to 2006

Background

Previous studies have shown influenza vaccine uptake in UK nursing home residents to be low. Very little information exists regarding the uptake of pneumococcal vaccine in this population. The formulation of policies relating to the vaccination of residents has been proposed as a simple step that may help improve vaccine uptake in care homes.

Methods

A postal questionnaire was sent to matrons of all care homes with nursing within the Greater Nottingham area in January 2006. Non respondents were followed up with up to 3 phone calls.

Results

30% (16/53) of respondents reported having a policy addressing influenza vaccination and 15% (8/53) had a policy addressing pneumococcal vaccination. Seasonal influenza vaccine coverage in care homes with a vaccination policy was 87% compared with 84% in care homes without a policy (p = 0.47). The uptake of pneumococcal vaccination was found to be low, particularly in care homes with no vaccination policy. Coverage was 60% and 32% in care homes with and without a vaccination policy respectively (p = 0.06). This result was found to be statistically significant on multivariate analysis (p = 0.03, R = 0.46)

Conclusion

The uptake of influenza vaccine among care home residents in the Nottingham region is relatively high, although pneumococcal vaccine uptake is low. This study shows that there is an association between pneumococcal vaccine uptake and the existence of a vaccination policy in care homes, and highlights that few care homes have vaccination policies in place.     

Influenza vaccination in old age.

Influenza is responsible for at least 3000-4000 deaths per year in the UK. During epidemics, death rates from pneumonia and influenza are much higher in elderly than younger people. With vaccination, the substantial medical and economic costs associated with influenza epidemics can be avoided. Countries with blanket vaccination have seen major reductions in morbidity and mortality. The vaccine is safe and effective in elderly people. Vaccination programmes for health-care workers who have contact with elderly people have also been shown to be effective in reducing deaths from influenza among this group.     

Universal influenza vaccination in the United States: are we ready? Report of a meeting

Universal influenza vaccination has been proposed as one strategy to improve vaccination coverage and disease prevention. In October 2005, influenza and vaccination experts, public health practitioners, representatives from medical professional societies, influenza vaccine manufacturers, and managed care organizations met to assess whether current data were sufficient to support an expansion of universal influenza vaccination and to define information gaps and potential barriers to implementation. Presenters at the meeting documented the substantial burden of influenza disease among all age groups, the major role of children in transmission, and the effectiveness of vaccine, especially in healthy children and adults. Observational studies and a mathematical model suggested that indirect protection, or "herd immunity," resulting from vaccination of school-age children would substantially reduce the incidence of disease in other age groups. Economic analyses generally showed that vaccination of healthy children and adults is cost-effective and is sensitive to vaccine cost, population group, and season. Influenza vaccination received annually over several years is safe and effective, but data on long-term use are limited. Challenges to expanded recommendations include maintenance of the vaccine supply, implementation of a feasible and effective strategy for vaccine delivery, the burden on the public health infrastructure, public acceptability, and financing. Overall, meeting attendees favored incremental expansion of recommendations, potentially toward universal influenza vaccination. They preferred to expand recommendations among children first, because children have a higher risk of illness, compared with healthy adults; because there is greater feasibility of implementation of the recommendations among children; and because of the potential for herd immunity decreasing morbidity and mortality among adults.