Influenza In Long-term Care Facilities Research Articles

Oseltamivir for the Prevention of Influenza in Residents of Long-Term Care Facilities


 The clinical effectiveness of oseltamivir for the prevention of influenza in residents of long-term care facilities compared to no prophylaxis is unclear. The evidence we identified is inconclusive due to limitations in the quality of studies.
 We did not find any evidence on the safety of oseltamivir for preventing influenza in long-term care facilities.
 We did not find any studies on the clinical effectiveness or safety of oseltamivir prophylaxis in long-term care facilities compared to placebo.

Geographic Variation in Pneumonia and Influenza in Long-Term Care Facilities: A National Study.

There is large county-level geographic variation in pneumonia and influenza hospitalizations among short-stay and long-stay long-term care facility residents in the United States. Long-term care facilities in counties in the Southern and Midwestern regions had the highest rates of pneumonia and influenza from 2013 to 2015. Future research should identify reasons for these geographic differences.

The effect of timing of oseltamivir chemoprophylaxis in controlling influenza A H3N2 outbreaks in long-term care facilities in Manitoba, Canada, 2014-2015: a retrospective cohort study.

This study examined the effect of the timing of administration of oseltamivir chemoprophylaxis for the control of influenza A H3N2 outbreaks among residents in long-term care facilities (LTCFs) in Manitoba, Canada, during the 2014-2015 influenza season. A retrospective cohort study was conducted of all LTCF influenza A H3N2 outbreaks (n=94) using a hierarchical logistic regression analysis. The main independent variable was how many days passed between the start of the outbreak and commencement of oseltamivir chemoprophylaxis. The dependent variable was whether each person in the institution developed influenza-like illness (yes or no). Delay of oseltamivir chemoprophylaxis was associated with increased odds of infection in both univariate (t=5·41; df=51; P<·0001) and multivariable analyses (t=6·04; df=49; P<·0001) with an adjusted odds ratio of 1.3 (95% confidence interval [CI], 1·2-1·5) per day for influenza A H3N2. The sooner chemoprophylaxis is initiated, the lower the odds of secondary infection with influenza in LTCFs during outbreaks caused by influenza A H3N2 in Manitoba. For every day that passed from the start of the outbreak to the initiation of oseltamivir, the odds of a resident at risk of infection in the facility developing symptomatic infection increased by 33%.

Influenza in long-term care facilities.

Long‐term care facility environments and the vulnerability of their residents provide a setting conducive to the rapid spread of influenza virus and other respiratory pathogens. Infections may be introduced by staff, visitors or new or transferred residents, and outbreaks of influenza in such settings can have devastating consequences for individuals, as well as placing extra strain on health services. As the population ages over the coming decades, increased provision of such facilities seems likely. The need for robust infection prevention and control practices will therefore remain of paramount importance if the impact of outbreaks is to be minimised. In this review, we discuss the nature of the problem of influenza in long‐term care facilities, and approaches to preventive and control measures, including vaccination of residents and staff, and the use of antiviral drugs for treatment and prophylaxis, based on currently available evidence.

The Effect of Individual Movements and Interventions on the Spread of Influenza in Long-Term Care Facilities.

Nosocomial influenza poses a serious risk among residents of long-term care facilities (LTCFs). We sought to evaluate the effect of resident and staff movements and contact patterns on the outcomes of various intervention strategies for influenza control in an LTCF. We collected contact frequency data in Canada's largest veterans' LTCF by enroling residents and staff into a study that tracked their movements through wireless tags and signal receivers. We analyzed and fitted the data to an agent-based simulation model of influenza infection, and performed Monte-Carlo simulations to evaluate the benefit of antiviral prophylaxis and patient isolation added to standard (baseline) infection control practice (i.e., vaccination of residents and staff, plus antiviral treatment of residents with symptomatic infection). We calibrated the model to attack rates of 20%, 40%, and 60% for the baseline scenario. For data-driven movements, we found that the largest reduction in attack rates (12.5% to 27%; ANOVA P < 0.001) was achieved when the baseline strategy was combined with antiviral prophylaxis for all residents for the duration of the outbreak. Isolation of residents with symptomatic infection resulted in little or no effect on the attack rates (2.3% to 4.2%; ANOVA P > 0.2) among residents. In contrast, parameterizing the model with random movements yielded different results, suggesting that the highest benefit was achieved through patient isolation (69.6% to 79.6%; ANOVA P < 0.001) while the additional benefit of prophylaxis was negligible in reducing the cumulative number of infections. Our study revealed a highly structured contact and movement patterns within the LTCF. Accounting for this structure-instead of assuming randomness-in decision analytic methods can result in substantially different predictions.

Building-level analyses to prospectively detect influenza outbreaks in long-term care facilities: New York City, 2013-2014

Timely outbreak detection is necessary to successfully control influenza in long-term care facilities (LTCFs) and other institutions. To supplement nosocomial outbreak reports, calls from infection control staff, and active laboratory surveillance, the New York City (NYC) Department of Health and Mental Hygiene implemented an automated building-level analysis to proactively identify LTCFs with laboratory-confirmed influenza activity. Geocoded addresses of LTCFs in NYC were compared with geocoded residential addresses for all case-patients with laboratory-confirmed influenza reported through passive surveillance. An automated daily analysis used the geocoded building identification number, approximate text matching, and key-word searches to identify influenza in residents of LTCFs for review and follow-up by surveillance coordinators. Our aim was to determine whether the building analysis improved prospective outbreak detection during the 2013-2014 influenza season. Of 119 outbreaks identified in LTCFs, 109 (92%) were ever detected by the building analysis, and 55 (46%) were first detected by the building analysis. Of the 5,953 LTCF staff and residents who received antiviral prophylaxis during the 2013-2014 season, 929 (16%) were at LTCFs where outbreaks were initially detected by the building analysis. A novel building-level analysis improved influenza outbreak identification in LTCFs in NYC, prompting timely infection control measures.

Guidance for practitioners on the use of antiviral drugs to control influenza outbreaks in long-term care facilities in Canada, 2014-2015 season.

The AMMI Canada Guidelines document 'The use of antiviral drugs for influenza: A foundation document for practitioners', published in the Autumn 2013 issue of the Journal, outlines the recommendations for the use of antiviral drugs to treat influenza. This article, which represents the first of two updates to these guidelines published in the current issue of the Journal, aims to inform health care professionals of the increased risk for influenza in long-term care facilities due to a documented mismatch between the components chosen for this season's vaccine and currently circulating influenza strains. Adjusted recommendations for the use of antiviral drugs for influenza in long-term care facilities for this season are provided.

Inducing Herd Immunity against Seasonal Influenza in Long-Term Care Facilities through Employee Vaccination Coverage: A Transmission Dynamics Model.

Introduction. Vaccinating healthcare workers (HCWs) in long-term care facilities (LTCFs) may effectively induce herd immunity and protect residents against influenza-related morbidity and mortality. We used influenza surveillance data from all LTCFs in New Mexico to validate a transmission dynamics model developed to investigate herd immunity induction. Material and Methods. We adjusted a previously published transmission dynamics model and used surveillance data from an active system among 76 LTCFs in New Mexico during 2006-2007 for model validation. We used a deterministic compartmental model with a stochastic component for transmission between residents and HCWs in each facility in order to simulate the random variation expected in such populations. Results. When outbreaks were defined as a dichotomous variable, our model predicted that herd immunity could be induced. When defined as an attack rate, the model demonstrated a curvilinear trend, but insufficiently strong to induce herd immunity. The model was sensitive to changes in the contact parameter β but was robust to changes in the visitor contact probability. Conclusions. These results further elucidate previous studies' findings that herd immunity may not be induced by vaccinating HCWs in LTCFs; however, increased influenza vaccination coverage among HCWs reduces the probability of influenza infection among residents.

Guidance on the use of antiviral drugs for influenza in acute care facilities in Canada, 2014-2015.

This article represents the second update to the AMMI Canada Guidelines document on the use of antiviral drugs for influenza. The article aims to inform health care professionals of the increased risk for influenza in long-term care facilities due to a documented mismatch between the components chosen for this season's vaccine and currently circulating influenza strains. Adjusted recommendations for the use of antiviral drugs for influenza in the acute care setting for this season are provided.

Importance of Employee Vaccination against Influenza in Preventing Cases in Long-Term Care Facilities

Employees of long-term care facilities (LTCFs) who have contact with residents should be vaccinated against influenza annually to reduce influenza incidence among residents. This investigation estimated the magnitude of the benefit of this recommendation. The New Mexico Department of Health implemented active surveillance in all of its 75 LTCFs during influenza seasons 2006-2007 and 2007-2008. Information about the number of laboratory-confirmed cases of influenza and the proportion vaccinated of both residents and direct-care employees in each facility was collected monthly. LTCFs reporting at least 1 case of influenza (defined alternately by laboratory confirmation or symptoms of influenza-like illness [ILI]) among residents were compared with LTCFs reporting no cases of influenza. Regression modeling was used to obtain adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for the association between employee vaccination coverage and the occurrence of influenza outbreaks. Covariates included vaccination coverage among residents, the staff-to-resident ratio, and the proportion of filled beds. Seventeen influenza outbreaks were reported during this 2-year period of surveillance. Eleven of these were laboratory confirmed (n = 21 residents) and 6 were defined by ILI (n = 40 residents). Mean influenza vaccination coverage among direct-care employees was 51% in facilities reporting outbreaks and 60% in facilities not reporting outbreaks (P = .12). Increased vaccination coverage among direct-care employees was associated with fewer reported outbreaks of laboratory-confirmed influenza (aOR, 0.97 [95% CI, 0.95-0.99]) and ILI (aOR, 0.98 [95% CI, 0.96-1.00]). High vaccination coverage among direct-care employees helps to prevent influenza in LTCFs.

Influenza in long-term care facilities: Preventable, detectable, treatable

Influenza in long-term care facilities is an ever more challenging problem. Vaccination of residents and health care workers is the most important preventive measure. Although vaccine efficacy has been questioned, the preponderance of data favors vaccination. Antiviral resistance complicates postexposure chemoprophylaxis and treatment. Factors that limit the choice of antiviral agents in this patient population include limited vaccine supplies and impaired dexterity and confusion in long-term care residents.

Benefits of increasing the dose of influenza vaccine in residents of long‐term care facilities: A randomized placebo‐controlled trial

Increased vaccine doses and mid-season boosting may increase the proportion of residents with protective immunity from influenza in long-term care facilities. In a multi-center study (1997-1998), 815 residents from 14 long-term care facilities were assigned at random to receive 15 or 30 microg of inactivated influenza vaccine, followed by a 15 microg booster vaccine or a placebo vaccine at Day 84. Seroresponses were re-analyzed by hemagglutination-inhibition (> or =4-fold titer increases, protective titer > or =40, geometric mean titers. Forty percent of the participants had pre-vaccination titers > or =40. At Day 25 after vaccination, this increased to 66.3% after a 15 microg dose versus 73.3% after a dose of 30 microg (P = 0.049). Participants receiving a 30 microg dose followed by a 15 microg booster showed more > or =4-fold titer increases at Day 109 (43.6% vs. 35.4%, P = 0.003) and protective titers > or =40 (74.2% vs. 64.6%, P = 0.041), compared to those receiving only a 15 microg dose. Differences were most apparent in participants with low pre-vaccination titers. Booster vaccination after an initial 15 microg dose of the vaccine did not increase the protective rate (61.9% vs. 63.9% after placebo). The number of participants needed to vaccinate to protect one additional resident by a dose of 15 microg was 4, by a dose of 30 microg 3, and 15 when using a 30 microg dose instead of 15 microg. Doubling the dose of influenza vaccine increased protection-related responses among residents of long-term care facilities, especially in those with low pre-vaccination titers.

Increasing Influenza Immunization for Long‐Term Care Facility Staff Using Quality Improvement

To improve staff immunization rates for influenza in long-term care facilities (LTCFs). A quality improvement project. LTCFs ranging in size from 50 to 2,000 beds. Staff members at facilities. Change in staff influenza immunization rate. Of the 13 nursing homes involved, 11 improved their staff influenza immunization rates; nine improved more than 10%, and six improved to a rate greater than 55%, a level that corresponds to substantial protection against outbreaks. Staff education was essential but insufficient. Direct encouragement and dramatic informative endeavors helped, as did financial incentives, competitions, and requiring unambiguously worded consents for refusals. Paying staff members $150 each achieved improvement rapidly. Quality improvement increased staff immunization rates at LTCFs, which reduces the risk of an influenza outbreak. Based on the insights learned about effective changes, the project developed a change package for use by other LTCFs.

Outbreaks of influenza in long-term care facilities in New York City (NYC), 2001-2004

BACKGROUND: Long-term care facilities (LTCF) are vulnerable to influenza outbreaks (OB), but limited primary data exist on the experiences of LTCFs during influenza OBs and the use and impact of antiviral chemoprophylaxis. METHODS: OBs of influenza-like illness (ILI) occurring from October 2001 through May 2004 in LTCFs in NYC were identified through required standardized reports from LTCFs and surveillance of laboratory reports positive for influenza. An OB was defined using NY State's standard definition: 1 laboratory-confirmed case of influenza or a cluster of >2 cases of ILI on a LTCF unit. Multivariate analysis was used to examine the effect of prophylaxis timing on mean duration of OBs, proportion of ill residents, and proportion of case deaths during influenza A OBs, adjusting for influenza season and facility size. RESULTS: There were 89 reported OBs of respiratory illness in 59 of 180 LTCFs; 21 reported multiple OBs. The causative agent was identified in 78 OBs: influenza A, 69; influenza B, 6; respiratory syncytial virus (RSV), 2; human metapneumovirus, 1; unknown, 9. Of 73 influenza OBs in which rapid antigen testing was used, 13 (18%) were identified only by viral culture. The impact of outbreaks is presented in the table below. Impact of Respiratory Infection OBs All OBs Influenza A OBs N=89 N=69 Total Median (Range) Total Median (Range) Number Residents 30,965 270 (60, 1926) 24,182 270 (60, 1926) Number III Residents 1917 17 (1, 96) 1485 17 (1, 96) Incidence Proportion (per 100 residents) – 6.0 (0.4, 32.5) – 6.0 (0.4, 27.5) Number Hospitalizations 174 1.0 (0, 38) 141 1.0 (0, 38) Number Deaths 42 ∗ 0.0 (0, 6) 34 † 0.0 (0, 6) Number III Staff 328 ‡ 1.0 (0, 49) 277 § 1.0 (0, 49) Duration of OB (days) – 9.0 (0, 75) ¶ – 8.5 (0, 44) # ∗ N=88 † N=68 ‡ N=87 § N=67 ¶ N=82 # N=64 Amantadine prophylaxis was initiated in 88% (61/69) of influenza A OBs and was administered facility-wide in 75% (46/61). The median time between onset of first case of illness and initiation of prophylaxis was 5 days and the median duration of OB after initiation of prophylaxis was 4 days. Initiation of prophylaxis within 5 days of OB onset was associated with a shorter mean duration of outbreak, lower mean proportion of ill residents, and lower mean proportion of case deaths (p CONCLUSIONS: Influenza A caused the vast majority of OB of respiratory illness in LTCF in NYC. Prompt initiation of amantadine prophylaxis may shorten the duration and morbidity of OB. Using rapid tests alone may miss approximately 1/5 of influenza OBs in LTCFs.

Spotlight on zanamivir in influenza.

Zanamivir is a potent competitive inhibitor of the neuraminidase glycoprotein, which is essential in the infective cycle of influenza A and B viruses. Zanamivir (10 mg by inhalation via the Diskhaler twice daily, or 10 mg inhaled plus 6.4 mg intranasally 2 or 4 times daily, for 5 days) reduced the median time to alleviation of major influenza symptoms by up to 2.5 days compared with placebo. Significant reductions of 1 to 2.5 days versus placebo were observed with inhaled zanamivir in phase III trials involving otherwise healthy adults, high-risk patients or children aged 5 to 12 years. Accelerated return to normal activities, and reduced interference with sleep, consumption of relief medication and incidence of complications leading to antibacterial use were also observed with zanamivir. When used for prophylaxis, inhaled zanamivir 10 to 20 mg/day for 10 days to 4 weeks (plus 6.4 mg/day intranasally in one trial) prevented influenza A in 67% of recipients in a university community, significantly reduced the number of families with new cases of influenza compared with placebo or prevented new cases of influenza in long-term care facilities. The tolerability of inhaled or intranasal zanamivir was similar to that of placebo in otherwise healthy adults, high-risk and elderly patients, and children. Recommended dosages of zanamivir did not adversely affect pulmonary function in patients with respiratory disorders in a well-controlled trial, although there have been rare reports of bronchospasm and/or a decline in respiratory function. In conclusion, zanamivir (used within 48 hours of symptom development) reduces the duration of symptomatic illness, causes accelerated return to normal activities or reduces complications requiring antibacterial use in adults, high-risk individuals and children with influenza. Vaccination remains the intervention of choice for prophylaxis in selected populations. However, the efficacy, good tolerability profile and lack of resistance with zanamivir make it a useful option, particularly in those not covered or inadequately protected by vaccination, who are able to use the inhalation device. The use of zanamivir in patients with respiratory disorders remains unclear because of concerns regarding its potential for bronchospasm. Prospective cost-effectiveness analyses and investigations of efficacy in preventing serious complications of influenza, particularly in high-risk patients, are required. Zanamivir shows potential for prophylaxis in persons for whom vaccination is contraindicated or ineffective, in elderly or high-risk patients in long-term care facilities and in households.

Zanamivir: an update of its use in influenza.

Zanamivir is a potent competitive inhibitor of the neuraminidase glycoprotein, which is essential in the infective cycle of influenza A and B viruses. Zanamivir (10mg by inhalation via the Diskhaler twice daily, or 10mg inhaled plus 6.4mg intranasally two or four times daily, for 5 days) reduced the median time to alleviation of major influenza symptoms by up to 2.5 days compared with placebo. Significant reductions of 1 to 2.5 days versus placebo were observed with inhaled zanamivir in phase III trials involving otherwise healthy adults, high-risk patients or children aged 5 to 12 years. Accelerated return to normal activities, and reduced interference with sleep, consumption of relief medication and incidence of complications leading to antibacterial use were also observed with zanamivir. When used for prophylaxis, inhaled zanamivir 10 to 20 mg/day for 10 days to 4 weeks (plus 6.4 mg/day intranasally in one trial) prevented influenza A in 67% of recipients in a university community, significantly reduced the number of families with new cases of influenza compared with placebo or prevented new cases of influenza in long-term care facilities. The tolerability of inhaled or intranasal zanamivir was similar to that of placebo in otherwise healthy adults, high-risk and elderly patients, and children. Recommended dosages of zanamivir did not adversely affect pulmonary function in patients with respiratory disorders in a well-controlled trial, although there have been rare reports of bronchospasm and/or a decline in respiratory function. Zanamivir (used within 48 hours of symptom development) reduces the duration of symptomatic illness, causes accelerated return to normal activities or reduces complications requiring antibacterial use in adults, high-risk individuals and children with influenza. Vaccination remains the intervention of choice for prophylaxis in selected populations. However, the efficacy, good tolerability profile and lack of resistance with zanamivir make it a useful option, particularly in those not covered or inadequately protected by vaccination, who are able to use the inhalation device. The use of zanamivir in patients with respiratory disorders remains unclear because of concerns regarding its potential for bronchospasm. Prospective cost-effectiveness analyses and investigations of efficacy in preventing serious complications of influenza, particularly in high-risk patients, are required. Zanamivir shows potential for prophylaxis in persons for whom vaccination is contraindicated or ineffective, in elderly or high-risk patients in long-term care facilities and in households.