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.     

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.     

Prevention and control of type A influenza infections in nursing homes. Benefits and costs of four approaches using vaccination and amantadine

We developed a model to project morbidity, mortality, and costs attributable to type A influenza virus infections in nursing homes and to evaluate the relative benefits and costs of programs for prevention and control. Influenza vaccination was the most cost-effective intervention under various simulations in the model but usually allowed for higher rates of morbidity and mortality compared with other alternatives. The combined use of previous vaccination and chemoprophylaxis during outbreaks in the nursing home was associated with significantly fewer cases than use of vaccination alone, with only modest increases in net program costs. The use of chemoprophylaxis throughout the influenza season (without vaccination) resulted in the fewest number of illnesses, hospitalizations, and deaths but would cost at least 650% more than alternatives involving vaccination. Regardless of which strategy is chosen, our model suggests that influenza control programs in nursing homes are both beneficial and cost-effective and should be considered a part of standard care.     

Mortality caused by influenza and respiratory syncytial virus by age group in England and Wales 1999–2010

Please cite this paper as: Hardelid et al. (2012) Mortality caused by influenza and respiratory syncytial virus by age group in England and Wales 1999–2010. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2012.00345.x. Background: The mortality burden caused by influenza cannot be quantified directly from death certificates because of under‐recording; therefore, the estimated number of influenza deaths has to be obtained through statistical modelling. Objective: To estimate the number of deaths caused by influenza and respiratory syncytial virus (RSV) in England and Wales between 1999 and 2010 using a multivariable regression model. Methods: Generalised linear models were used to estimate weekly deaths by age group (<15, 15–44, 45–74 and 75+ years) as a function of positive influenza and RSV isolates. Adjustment was made for temperature variation (using weekly means of daily Central England temperature time series), underlying seasonal variation and temporal trends. The parameters from the model were used to predict the number of deaths caused by influenza and RSV across winter seasons. Results: Between 7000 and 25 000 deaths across all ages were associated with influenza in the winter periods 1999–2009. The mortality burden was the highest among the over 75 age group, among whom 2·5–8·1% of deaths were caused by influenza. The lowest number of influenza deaths was estimated for the winter 2009/2010 when pandemic influenza A/H1N1 (2009) was the predominant circulating strain. RSV accounted for 5000–7500 deaths each winter season. Conclusions: The model presented provides a robust and reasonable approach to estimating the number of deaths caused by influenza and RSV by age group at the end of each winter.     

Estimates of mortality attributable to influenza and RSV in the United States during 1997–2009 by influenza type or subtype,age, cause of death,and risk status

Background

Influenza and respiratory syncytial virus (RSV) cause substantial mortality from respiratory and other causes in the USA, especially among people aged 65 and older.

Objectives

We estimated the influenza-attributable mortality and RSV-attributable mortality in the USA, stratified by age and risk status, using outcome definitions with different sensitivity and specificity.

Methods

Influenza- and RSV-associated mortality was assessed from October 1997–March 2009 using multiple linear regression modeling on data obtained from designated government repositories.

Results

The main outcomes and measures included mortality outcome definitions—pneumonia and influenza, respiratory broad, and cardiorespiratory disease. A seasonal average of 10 682 (2287–16 363), 19 100 (4862–29 245), and 28 169 (6797–42 316) deaths was attributed to influenza for pneumonia and influenza, respiratory broad, and cardiorespiratory outcome definitions, respectively. Corresponding values for RSV were 6211 (4584–8169), 11 300 (8546–14 244), and 17 199 (13 384–21 891), respectively. A/H3N2 accounted for seasonal average of 71% influenza-attributable deaths; influenza B accounted for most (51–95%) deaths during four seasons. Approximately 70% influenza-attributable deaths occurred in individuals ≥75 years, with increasing mortality for influenza A/H3N2 and B, but not A/H1N1. In children aged 0–4 years, an average of 97 deaths was attributed to influenza (A/H3N2 = 49, B = 33, A/H1N1 = 15) and 165 to respiratory broad outcome definition (RSV). Influenza-attributable mortality was 2·94-fold higher in high-risk individuals.

Conclusions

Influenza-attributable mortality was highest in older and high-risk individuals and mortality in children was higher than reported in passive Centers for Disease Control and Prevention surveillance. Influenza B-attributable mortality was higher than A in four of 12 seasons. Our estimates represent an updated assessment of influenza-attributable mortality in the USA.     

An outbreak of influenza A (H3N2) in a well immunized nursing home population.

OBJECTIVE: To describe the epidemiologic features of an outbreak of influenza A that occurred in a skilled nursing home although over 90 percent of the resident population had previously received influenza vaccine. DESIGN: Retrospective cohort study. SETTING: Skilled nursing home facility in western New York State. PATIENTS: Nursing home residents and patient-care staff. MAIN OUTCOME MEASURE: Incidence of influenza-like illness among vaccinated versus unvaccinated nursing home residents and staff. RESULTS: Thirty-seven of 124 residents (attack rate = 30%) and 18 of 146 staff (attack rate = 12%) had an influenza-like illness. Staff illness began 16 days prior to onset among residents. Six cases of pneumonia and three influenza-related deaths occurred, all among the vaccinated residents. Ninety percent of the nursing home residents and 10% of the staff received the influenza vaccine prior to the outbreak. The calculated vaccine efficacies were minus 21% and plus 45% for residents and staff, respectively. CONCLUSION: While antigenic drift of the circulating influenza virus was the major factor in the apparent vaccine failure, the observed poor staff immunization rate (10%) and absence of surveillance which precluded the use of amantadine chemoprophylaxis suggest that the use of these strategies may be of importance in controlling influenza outbreaks in nursing homes.     

A 5-year experience with influenza prevention and containment in a program of all-inclusive care for elderly adults

BACKGROUND: Influenza causes mortality and morbidity in the frail elderly population. Influenza prevention and mitigation models need to be developed for this population. METHODS: An observational study at a Program for All-Inclusive Care for the Elderly (PACE) during years 1999-2004. Participants were frail elderly adults who meet the state Medicaid requirements for nursing home placement. RESULTS: Over 91% of participants have been immunized yearly since the beginning of the program. Employee immunization has increased yearly from 61% to 90%, and caregivers known to be immunized increased from 9% to 62% over the last 4-year period. During 2 influenza seasons, we placed all our participants on ramantidine prophylaxis within a 2-week period. CONCLUSIONS: The incentives and flexibility offered by PACE have allowed our participants to enjoy much higher influenza immunization rates than experienced by other elderly adults while also prophylaxing employees and caregivers. Our systems have allowed us to prophylax all our participants within a short time during 2 influenza seasons. Nonetheless, many questions remain regarding the optimal way to decrease the burden of influenza in frail elderly adults. With adequate integration and supplementary financing, PACE programs throughout the United States could serve as laboratories to test candidate interventions.     

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.     

New estimates of influenza-related pneumonia and influenza hospitalizations among the elderly.

OBJECTIVES: The aim of this study is to present a method to provide accurate estimates of influenza-associated pneumonia and influenza (P&I) hospitalizations and costs for use in tracking the continuing burden of influenza. METHODS: We estimated influenza-associated P&I hospitalizations among the U.S. elderly population for six influenza seasons, 1990-91 through 1995-96, by applying a Poisson regression model to national influenza virus surveillance information and Medicare administrative data. This model is similar to that recently published by the U.S. National Centers for Disease Control and Prevention (CDC) to estimate influenza-related mortality. RESULTS: During the six years of the study, 318,666 (9.8%) of P&I hospitalizations were estimated to be associated with influenza: range = 25,819 to 70,068 per year; average annual cost = $372.3 million. Influenza A(H3N2) was associated with 73.9% of influenza-related P&I hospitalizations; influenza B with 21.3% and influenza A(H1N1) with 4.8%. CONCLUSIONS: Our estimates were consistent with the estimates of influenza-associated P&I mortality reported by CDC. Thus, we suggest that estimates of influenza-associated morbidity and costs based on virus surveillance and administrative data may be used for monitoring the impact of influenza and of intervention strategies.     

Mortality attributable to pandemic influenza A (H1N1) 2009 in San Luis Potosí, Mexico

Please cite this paper as: Comas‐García et al. (2011) Mortality attributable to pandemic influenza A (H1N1) 2009 in San Luis Potosí, Mexico. Influenza and Other Respiratory Viruses 5(2), 76–82. Background Acute respiratory infections are a leading cause of morbidity and mortality worldwide. Starting in 2009, pandemic influenza A(H1N1) 2009 virus has become one of the leading respiratory pathogens worldwide. However, the overall impact of this virus as a cause of mortality has not been clearly defined. Objectives To determine the impact of pandemic influenza A(H1N1) 2009 on mortality in a Mexican population. Methods We assessed the impact of pandemic influenza virus on mortality during the first and second outbreaks in San Luis Potosí, Mexico, and compared it to mortality associated with seasonal influenza and respiratory syncytial virus (RSV) during the previous winter seasons. Results We estimated that, on average, 8·1% of all deaths that occurred during the 2003–2009 seasons were attributable to influenza and RSV. During the first pandemic influenza A(H1N1) 2009 outbreak, there was an increase in mortality in persons 5–59 years of age, but not during the second outbreak (Fall of 2009). Overall, pandemic influenza A (H1N1) 2009 outbreaks had similar effects on mortality to those associated with seasonal influenza virus epidemics. Conclusions The impact of influenza A(H1N1) 2009 virus on mortality during the first year of the pandemic was similar to that observed for seasonal influenza. The establishment of real‐time surveillance systems capable of integrating virological, morbidity, and mortality data may result in the timely identification of outbreaks so as to allow for the institution of appropriate control measures to reduce the impact of emerging pathogens on the population.     

Influenza vaccination in elderly people.

Influenza is an important cause of morbidity and mortality in the elderly. Influenza vaccine has been shown to successfully reduce influenza- and pneumonia-associated hospitalizations and deaths, but the antibody induction by influenza vaccines is not always optimal in the elderly. The lower serological efficacy of influenza vaccines that is often observed in the elderly may be due to a multitude of factors. Here we will discuss some of these factors. These include health status and previous exposures to influenza viruses. In addition, we will discuss possibilities to improve antibody responses to influenza vaccination.     

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.     

The effect of culture-positive influenza type A on resource use and adverse events in nursing home residents

OBJECTIVES: To determine adverse clinical events and resource utilization associated with culture-positive influenza A in nursing home residents. DESIGN: A retrospective cohort study with cases and controls. SETTING: Seven hundred twenty-one-bed skilled nursing facility. PARTICIPANTS: One hundred fifty-four residents (21% of all residents) from whom influenza A was isolated during the 1997/98 season and matched controls. MEASUREMENTS: Baseline parameters, staff interventions, diagnostic tests, and adverse events were recorded from 60 days before to 60 days after specimen collection. The difference between each individual's before and after measurements determined excess utilization secondary to influenza. Controls were studied to determine time series effects. RESULTS: Baseline Minimum Data Set and nutritional parameters demonstrated significantly greater (P <.05) feeding dependency and lower serum albumin in the control group. Time series effects in the control group were negligible. Among cases, there were nine deaths within 30 days; among controls, there were four (chi2 P =.26). Within 30 days of onset, an average excess of 18 notations by nursing staff, one phone call to the physician, and one to family was noted per case. In half of cases, a nonscheduled physician visit was required. There was a 20% excess in physician orders for oxygen and bronchodilators. Chest x-rays were performed in half of the cases, and antibiotics were prescribed to half. Sixteen percent of cases had radiographic pneumonia, and 2% had congestive heart failure. The average cost for excess chest x-rays, laboratory services, antimicrobials, ambulance calls, hospital days, and emergency room and physician visits was $943.44. This does not include efforts by nursing home staff who accommodate functional decline on-site. CONCLUSION: An unexpected finding was that there were more impaired individuals who were less likely to have influenza detected or less likely to acquire influenza in the control group than in the influenza group. The morbidity, mortality, excess staff effort, and measured expenditure justify efforts to prevent influenza.     

Unusual outbreak of influenza A in a Wyoming nursing home

An explosive outbreak of Influenza A (H3N2) occurred during early February 1985 among the 55 residents of a nursing home in Douglas, Wyoming. Thirty of the 55 (55%) had febrile respiratory illnesses. Thirty-six (65%) had received influenza vaccine. The attack rate was 84% in unvaccinated and 39% in vaccinated persons. Vaccine efficacy was estimated to be 54%. There were eight cases of pneumonia in unvaccinated and four in vaccinated persons, three deaths in unvaccinated and one death in vaccinated persons. Complement fixation and hemagglutination inhibition tests on sera from 47 residents confirmed the diagnosis of Influenza A in the great majority of individuals, and furthermore showed very low levels of antibody for the Influenza A H1N1 and Influenza B components of the vaccine.     

Influenza vaccine and pneumonia mortality in a nursing home population

The effectiveness of immunization against influenza in elderly persons is uncertain. A retrospective cohort study in a New York City nursing home examined the occurrence of pneumonia and its related mortality over three consecutive influenza seasons (Nov 1 through April 30, 1979 to 1980, 1980 to 1981, and 1981 to 1982). Nearly one half of approximately 450 residents (mean age, 84 years) accepted immunization each year. The vaccinated and unvaccinated groups were similar. The attack rate of pneumonia did not differ significantly between the vaccinated and unvaccinated groups in any of the three influenza seasons. When influenza was occurring in the community (1979 to 1980 and 1980 to 1981), however, the risk of death from pneumonia in the unvaccinated group was three-fold higher than in the vaccinated group (60% vs 18% and 73% vs 25%, respectively). In a year when influenza was specifically sought and not found in the facility (1981 to 1982), however, vaccination did not affect pneumonia-related mortality. This study also suggests that estimates of mortality due to pneumonia should include deaths that occur up to 60 days after onset of pneumonia; shorter follow-up may overestimate the protective effect of vaccination.     

Clinical effectiveness of influenza vaccination in persons younger than 65 years with high-risk medical conditions: the PRISMA study

BACKGROUND: Influenza vaccination has consistently been shown to prevent all-cause death and hospitalizations during influenza epidemics among seniors. However, such benefits have not yet been demonstrated among younger individuals with high-risk medical conditions. In the present study, we evaluated the effectiveness of influenza vaccine in persons recommended for vaccination of any age during an epidemic. METHODS: We conducted a case-control study during the 1999-2000 influenza A epidemic nested in a cohort of 75,227 primary care patients. End points were all-cause mortality and episodes of hospitalizations or general practitioner (GP) visits for influenza, pneumonia, other acute respiratory disease, acute otitis media, myocardial infarction, heart failure, and stroke. The effectiveness of vaccination was evaluated by means of logistic regression analysis with adjustments for age, sex, prior health care use, medication use, and comorbid conditions. RESULTS: Among high-risk children and adolescents younger than 18 years (n=5933; 8% of the study population), 1 death, 3 hospitalizations for pneumonia, and 160 GP visits occurred. After adjustments, 43% (95% confidence interval [CI], 10%-64%) of visits were prevented. Among high-risk adults aged between 18 and 64 years (n=24 928; 33% of the study population), 47 deaths, 23 hospitalizations, and 363 GP visits occurred. After adjustments, vaccination prevented 78% of deaths (95% CI, 39%-92%), 87% of hospitalizations (95% CI, 39%-97%), and 26% of GP visits (95% CI, 7%-47%). Among elderly persons (n=44 366; 59% of the study population), 272 deaths and 166 hospitalizations occurred, and after adjustments the vaccine prevented these end points by 50% (95% CI, 23%-68%) and 48% (95% CI, 7%-71%), respectively. CONCLUSION: Persons with high-risk medical conditions of any age can substantially benefit from annual influenza vaccination during an epidemic.     

Mortality attributable to 9 common infections: significant effect of influenza a, respiratory syncytial virus, influenza B, norovirus, and parainfluenza in elderly persons

Background.Because there may be substantial hidden mortality caused by common seasonal pathogens, we estimated the number of deaths in elderly persons attributable to viruses and bacteria for which robust weekly laboratory surveillance data were available. Methods.On weekly time series (1999-2007) we used regression models to associate total death counts in individuals aged 65-74, 75-84, and ≥85 years (a population of 2.5 million) with pathogen circulation-influenza A (season-specific), influenza B, respiratory syncytial virus (RSV), parainfluenza, enterovirus, rotavirus, norovirus, Campylobacter, and Salmonella-adjusted for extreme outdoor temperatures. Results.Influenza A and RSV were significantly (P?相似文献   

The effect of a social work intervention to enhance advance care planning documentation in the nursing home

OBJECTIVES: To assess the effect of a multicomponent advance care planning intervention directed at nursing home social workers on identification and documentation of preferences for medical treatments and on patient outcomes. DESIGN: Controlled clinical trial. SETTING: New York City nursing home. PARTICIPANTS: One hundred thirty-nine newly admitted long-term care residents. INTERVENTION: Nursing home social workers were randomized to the intervention or control groups. The intervention consisted of baseline education in advance care planning that incorporated small-group workshops and role play/practice sessions for intervention social workers; structured advance care planning discussions with residents and their proxies at admission, after any change in clinical status, and at yearly intervals; formal structured review of residents' goals of care at preexisting regular team meetings; "flagging" of advance directives on nursing home charts; and feedback to individual healthcare providers of the congruence of care they provided and the preferences specified in the advance care planning process. Control social workers received an educational training session on New York State law regarding advance directives but no additional training or interventions. Subjects were enrolled from January 9, 2001 through May 25, 2003 and followed for 6 months after enrollment. MEASUREMENTS: Nursing home chart documentation of advance directives (healthcare proxies, living wills) and do-not-resuscitate orders; preferences for artificial nutrition and hydration, intravenous antibiotics, and hospitalization; and concordance of treatments received with documented preferences were compared for residents assigned to intervention and control social workers. RESULTS: Intervention residents were significantly more likely than residents in the control group to have their preferences regarding cardiopulmonary resuscitation (40% vs 20%, P=.005), artificial nutrition and hydration (47% vs 9%, P<.01), intravenous antibiotics (44% vs 9%, P<.01), and hospitalization (49% vs 16%, P<.01) documented in the nursing home chart. Control residents were significantly more likely than intervention residents to receive treatments discordant with their prior stated wishes. Two of 49 (5%) intervention residents received a treatment in conflict with their prior stated wishes (one hospitalization, one episode of intravenous antibiotics), compared with 17 of 96 (18%) control patients (P=.04). CONCLUSION: This generalizable intervention directed at nursing home social workers significantly improved the documentation and identification of patients' wishes regarding common life-sustaining treatments and resulted in a higher concordance between patients' prior stated wishes and treatments received.