Modeling the effects of influenza vaccination of health care workers in hospital departments

Considerations for de-escalating universal masking in healthcare centers

Three years after the beginning of the COVID-19 pandemic, better knowledge on the transmission of respiratory viral infections (RVI) including the contribution of asymptomatic infections encouraged most healthcare centers to implement universal masking. The evolution of the SARS-CoV-2 epidemiology and improved immunization of the population call for the infection and prevention control community to revisit the masking strategy in healthcare. In this narrative review, we consider factors for de-escalating universal masking in healthcare centers, addressing compliance with the mask policy, local epidemiology, the level of protection provided by medical face masks, the consequences of absenteeism and presenteeism, as well as logistics, costs, and ecological impact. Most current national and international guidelines for mask use are based on the level of community transmission of SARS-CoV-2. Actions are now required to refine future recommendations, such as establishing a list of the most relevant RVI to consider, implement reliable local RVI surveillance, and define thresholds for activating masking strategies. Considering the epidemiological context (measured via sentinel networks or wastewater analysis), and, if not available, considering a time period (winter season) may guide to three gradual levels of masking: (i) standard and transmission-based precautions and respiratory etiquette, (ii) systematic face mask wearing when in direct contact with patients, and (iii) universal masking. Cost-effectiveness analysis of the different strategies is warranted in the coming years. Masking is just one element to be considered along with other preventive measures such as staff and patient immunization, and efficient ventilation.

Vaccine mandates for healthcare workers beyond COVID-19

We provide ethical criteria to establish when vaccine mandates for healthcare workers are ethically justifiable. The relevant criteria are the utility of the vaccine for healthcare workers, the utility for patients (both in terms of prevention of transmission of infection and reduction in staff shortage), and the existence of less restrictive alternatives that can achieve comparable benefits. Healthcare workers have professional obligations to promote the interests of patients that entail exposure to greater risks or infringement of autonomy than ordinary members of the public. Thus, we argue that when vaccine mandates are justified on the basis of these criteria, they are not unfairly discriminatory and the level of coercion they involve is ethically acceptable-and indeed comparable to that already accepted in healthcare employment contracts. Such mandates might be justified even when general population mandates are not. Our conclusion is that, given current evidence, those ethical criteria justify mandates for influenza vaccination, but not COVID-19 vaccination, for healthcare workers. We extend our arguments to other vaccines.

Vaccination Strategies against Seasonal Influenza in Long Term Care Setting: Lessons from a Mathematical Modelling Study

BACKGROUND

seasonal influenza in nursing homes is a major public health concern, since in EU 43,000 long term care (LTC) facilities host an estimated 2.9 million elderly residents. Despite specific vaccination campaigns, many outbreaks in such institutions are occasionally reported. We explored the dynamics of seasonal influenza starting from real data collected from a nursing home located in Italy and a mathematical model. Our aim was to identify the best vaccination strategy to minimize cases (and subsequent complications) among the guests.

MATERIALS AND METHODS

after producing the contact matrices with surveys of both the health care workers (HCW) and the guests, we developed a mathematical model of the disease. The model consists of a classical SEIR part describing the spreading of the influenza in the general population and a stochastic agent based model that formalizes the dynamics of the disease inside the institution. After a model fit of a baseline scenario, we explored the impact of varying the HCW and guests parameters (vaccine uptake and vaccine efficacy) on the guest attack rates (AR) of the nursing home.

RESULTS

the aggregate AR of influenza like illness in the nursing home was 36.4% (ward1 = 56%, ward2 = 33.3%, ward3 = 31.7%, ward4 = 34.5%). The model fit to data returned a probability of infection of the causal contact of 0.3 and of the shift change contact of 0.2. We noticed no decreasing or increasing AR trend when varying the HCW vaccine uptake and efficacy parameters, whereas the increase in both guests vaccine efficacy and uptake parameter was accompanied by a slight decrease in AR of all the wards of the LTC facility.

CONCLUSION

from our findings we can conclude that a nursing home is still an environment at high risk of influenza transmission but the shift change room and the handover situation carry no higher relative risk. Therefore, additional preventive measures in this circumstance may be unnecessary. In a closed environment such as a LTC facility, the vaccination of guests, rather than HCWs, may still represent the cornerstone of an effective preventive strategy. Finally, we think that the extensive inclusion of real life data into mathematical models is promising and may represent a starting point for further applications of this methodology.

Effect of influenza vaccination among healthcare workers on hospital-acquired influenza in short-stay hospitalized patients: A multicenter pilot study in France

BACKGROUND

Exposure to infected healthcare workers (HCWs) is a source of hospital-acquired (HA) influenza. We estimated the risk of HA influenza for hospitalized patients by rate of influenza vaccine coverage (IVC) of HCWs.

METHODS

A case-case negative control study nested in a prospective cohort was conducted in 2 French university hospitals during 2 influenza seasons. Each inpatient with influenza-like illness (ILI) provided a nasal swab sample that was systematically analyzed for influenza virus by polymerase chain reaction (PCR) testing. An HA influenza case was a patient with a virological confirmation of influenza with onset of symptoms ≥72 hours after admission to the ward. The IVC rate of HCWs in each participating ward was calculated from the data provided by the occupational health departments. A mixed-effect logistic regression was performed with adjustments on patient sex, age, the presence of a potential source of influenza on the ward in the 5 days prior to the start of the ILI, type of ward and influenza season.

RESULTS

The overall HA influenza attack rate was 1.9 per 1,000 hospitalized patients. In total, 24 confirmed HA influenza cases and 141 controls were included. The crude odds ratio (OR) of HA influenza decreased from 0.52 (95% confidence interval [CI], 0.21-1.29) to 0.14 (95% CI, 0.03-0.63) when the IVC of HCWs increased from 20% to 40%. After adjustment, IVC ≥40% was associated with a risk reduction of HA influenza (aOR, 0.07; 95% CI, 0.01-0.78).

CONCLUSIONS

Considering a limited sample size, influenza vaccination of HCWs is highly suggestive of HA flu prevention among hospitalized patients.Trial Registration: clinicaltrials.gov identifier: NCT02198638.

System dynamic modelling of healthcare associated influenza -a tool for infection control

Background

The transmission dynamics of influenza virus within healthcare settings are not fully understood. Capturing the interplay between host, viral and environmental factors is difficult using conventional research methods. Instead, system dynamic modelling may be used to illustrate the complex scenarios including non-linear relationships and multiple interactions which occur within hospitals during a seasonal influenza epidemic. We developed such a model intended as a support for health-care providers in identifying potentially effective control strategies to prevent influenza transmission.

Methods

By using computer simulation software, we constructed a system dynamic model to illustrate transmission dynamics within a large acute-care hospital. We used local real-world clinical and epidemiological data collected during the season 2016/17, as well as data from the national surveillance programs and relevant publications to form the basic structure of the model. Multiple stepwise simulations were performed to identify the relative effectiveness of various control strategies and to produce estimates of the accumulated number of healthcare-associated influenza cases per season.

Results

Scenarios regarding the number of patients exposed for influenza virus by shared room and the extent of antiviral prophylaxis and treatment were investigated in relation to estimations of influenza vaccine coverage, vaccine effectiveness and inflow of patients with influenza. In total, 680 simulations were performed, of which each one resulted in an estimated number per season. The most effective preventive measure identified by our model was administration of antiviral prophylaxis to exposed patients followed by reducing the number of patients receiving care in shared rooms.

Conclusions

This study presents an system dynamic model that can be used to capture the complex dynamics of in-hospital transmission of viral infections and identify potentially effective interventions to prevent healthcare-associated influenza infections. Our simulations identified antiviral prophylaxis as the most effective way to control in-hospital influenza transmission.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-07959-7.

Awareness, Attitude, and Current Practices Toward Influenza Vaccination Among Physicians in India: A Multicenter, Cross-Sectional Study

Background: Although annual influenza vaccination is recommended for healthcare providers (HCPs), vaccination rate among HCPs in India is generally low. This cross-sectional survey was conducted to evaluate physicians' awareness, attitude, and current practices toward influenza vaccination in high-risk groups in India.

Methods: The survey was performed in June–July 2020, wherein consulting physicians, pulmonologists, diabetologists, obstetricians/gynecologists, or cardiologists across 14 cities completed a 39-item questionnaire consisting of 3 sections, one each on awareness, attitude, and practice patterns. Descriptive statistics were used to summarize the study results. Statistical analysis was performed for comparison of subgroups by physician specialty, city of practice (metro/non-metro), and zone of practice (north/south/east/west). Level of statistical significance was set at p < 0.05.

Results: In all, 780 physicians completed the survey. Of these, 3.97, 53.08, and 42.95% had high, medium, and low level of awareness about influenza/influenza vaccination, respectively. Statistically significant (p < 0.05) between-group differences were found by physician specialty and zone of practice. In terms of attitude toward vaccination of high-risk group subjects, only 0.9% physicians were “extremely concerned,” while the majority (92.56%) were “quite concerned” and 6.54% were a “little concerned,” with no reported significant differences between different subgroups. With regard to practice patterns, 82.82% of physicians offered influenza vaccines to their patients, 32.69% vaccinated 10–25% of patients per month, and 38.85% required and offered the vaccine to their office staff. Physicians' reasons for not prescribing influenza vaccines to patients included fear of side effects (16.54%), cost (15.64%), lack of awareness about availability (15.38%), absence of belief that it is beneficial (14.36%), history of side effects (13.46%), and patients' fear of needles (11.28%).

Conclusion: These findings suggest the need to implement educational strategies among physicians to enhance their awareness about influenza vaccination and improve their attitudes and current practices toward influenza vaccination especially in high-risk groups in India.

Promotion of the influenza vaccination to hospital staff during pre-employment health check: a prospective, randomised, controlled trial

Background

Vaccination is the most effective prevention of seasonal influenza. Despite its recommendation and active promotion, vaccination coverage remains low among healthcare staff. The goal of the study was to test if a pre-employment health check is a good opportunity to promote future vaccination against influenza among healthcare workers newly hired by a university hospital.

Methods

All new hospital employees active at the bedside who underwent a pre-employment health check between the end of 2016’s influenza epidemic and the start of the next influenza vaccination campaign were randomly allocated to a control group or an intervention group. The intervention consisted of a semi-structured dialog and the release of an information leaflet about influenza and influenza vaccination during the check-up, and the shipment of a postcard reminder 2 weeks before the next vaccination campaign. Vaccination rates during the campaign were compared among the two groups.

Results

Three hundred fifty-seven employees were included. Vaccination rates were similar in both groups: 79/172 (46%) in the control and 92/185 (50%) in the intervention group. A significantly higher rate of vaccination was noted among physicians (70/117, 60%) than among other employees (101/240, 42%, p = 0.001). In a pre-defined exploratory analysis among physicians, the vaccination rate was higher in the intervention group (36/51, 71%) than in the control group (34/65, 52%, p = 0.046).

Conclusions

Promotion of the influenza vaccine during pre-employment health check did not improve the vaccination rate of newly hired hospital healthcare workers overall during the next influenza vaccination campaign. Results suggest a favourable impact on the vaccination rate of physicians. Thus, there may be an interest in using communication strategies tailored to the different categories of healthcare workers to promote the influenza vaccine during pre-employment health check.

Trial registration

ClinicalTrials, NCT02758145. Registered 26 April 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12995-020-00285-w.

Withdrawn: Vaccine hesitancy among Maltese Healthcare workers toward influenza and novel COVID-19 vaccination

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WITHDRAWN: Needed: less influenza vaccine hesitancy and less presenteeism among health care workers in the COVID-19 era

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A rapid evidence appraisal of influenza vaccination in health workers: An important policy in an area of imperfect evidence

INTRODUCTION

The World Health Organization recommends vaccination of health workers (HWs) against influenza, but low uptake is intransigent.We conducted a Rapid Evidence Appraisal on: the risk of influenza in HWs, transmission risk from HWs to patients, the benefit of HW vaccination, and strategies for improving uptake. We aimed to capture a 'whole-of-system' perspective to consider possible benefits for HWs, employers and patients.

METHODS

We executed a comprehensive search of the available literature published from 2006 to 2018 in the English language. We developed search terms for seven separate questions following the PICO framework (population, intervention, comparators, outcomes) and queried nine databases.

RESULTS

Of 3784 publications identified, 52 met inclusion criteria. Seven addressed HW influenza risk, of which four found increased risk; 15 addressed influenza vaccine benefit to HWs or their employers, of which 10 found benefit; 11 addressed influenza transmission from HWs to patients, of which 6 found evidence for transmission; 12 unique studies addressed whether vaccinating HWs produced patient benefit, of which 9 concluded benefits accrued. Regarding the number of HWs needed to vaccinate (NNV) to deliver patient benefit, NNV estimates ranged from 3 to 36,000 but were in significant disagreement. Fourteen studies provided insights on strategies to improve uptake; the strongest evidence was for mandatory vaccination.

CONCLUSIONS

The evidence on most questions related to influenza vaccination in HWs is mixed and often of low-quality. Substantial heterogeneity exists in terms of study designs and settings, making comparison between studies difficult. Notwithstanding these limitations, a majority of studies suggests that influenza vaccination benefit HWs and their employers; and HWs are implicated in transmission events. The effects of vaccinating HWs on patient morbidity and mortality may include reductions in all-cause mortality and influenza-like illness (ILI). Taken together, the evidence suggests that HW vaccination is an important policy for HWs themselves, their employers, and their patients.

The potential economic value of influenza vaccination for healthcare workers in The Netherlands

Background

Despite the clinical evidence, influenza vaccination coverage of healthcare workers remains low. To assess the health economic value of implementing an influenza immunization program among healthcare workers (HCW) in University Medical Centers (UMCs) in the Netherlands, a cost‐benefit model was developed using a societal perspective.

Methods/Patients

The model was based on a trial performed among all UMCs in the Netherlands that included both hospital staff and patients admitted to the pediatrics and internal medicine departments. The model structure and parameters estimates were based on the trial and complemented with literature research, and the impact of uncertainty explored with sensitivity analyses.

Results

In a base‐case scenario without vaccine coverage, influenza‐related annual costs were estimated at € 410 815 for an average UMC with 8000 HCWs and an average occupancy during the influenza period of 6000 hospitalized patients. Of these costs, 82% attributed to the HCWs and 18% were patient‐related. With a vaccination coverage of 15.47%, the societal program’s savings were € 2861 which corresponds to a saving of € 270.53 per extended hospitalization. Univariate sensitivity analyses show that the results are most sensitive to changes in the model parameters vaccine effectiveness in reducing influenza‐like illness (ILI) and the vaccination‐related costs.

Conclusion

In addition to the decreased burden of patient morbidity among hospitalized patients, the effects of the hospital immunization program slightly outweigh the economic investments. These outcomes may support healthcare policymakers’ recommendations about the influenza vaccination program for healthcare workers.

Mathematical models of infection transmission in healthcare settings: recent advances from the use of network structured data

PURPOSE OF REVIEW

Mathematical modeling approaches have brought important contributions to the study of pathogen spread in healthcare settings over the last 20 years. Here, we conduct a comprehensive systematic review of mathematical models of disease transmission in healthcare settings and assess the application of contact and patient transfer network data over time and their impact on our understanding of transmission dynamics of infections.

RECENT FINDINGS

Recently, with the increasing availability of data on the structure of interindividual and interinstitution networks, models incorporating this type of information have been proposed, with the aim of providing more realistic predictions of disease transmission in healthcare settings. Models incorporating realistic data on individual or facility networks often remain limited to a few settings and a few pathogens (mostly methicillin-resistant Staphylococcus aureus).

SUMMARY

To respond to the objectives of creating improved infection prevention and control measures and better understanding of healthcare-associated infections transmission dynamics, further innovations in data collection and parameter estimation in modeling is required.

Infectious disease transmission: survey of contacts between hospital-based healthcare workers and working adults from the general population

BACKGROUND

Healthcare workers (HCWs) may be the inadvertent interface between the healthcare setting and the community for infectious diseases transmission.

AIM

To investigate HCWs' contacts during a work day and compare these against working adults from the general population.

METHODS

Prospective survey of contacts through 24 h self-reported diary in three public sector tertiary care hospitals and community-based working adults in Singapore. Participants were HCWs and working adults from the community.

FINDINGS

In all, 211 HCWs and 1028 working adults reported a total of 4066 and 9206 contacts. HCWs reported more work-related contacts than community-based working adults (median of 13 versus 4), and more contacts that were neither household nor work-related (1 versus 0) but fewer household contacts (2 versus 3). HCWs reported more work-related contacts involving physical contacts, and more new contacts particularly with short duration (≤15 min) compared to community-based working adults. Among different HCW types, doctors reported the highest whereas ward-based nurses reported the lowest total work-related contacts. Around half of ward-based and clinic-based nurses' contacts involved physical touch. Work-related contacts reported by clinic-based nurses, doctors, and assorted HCWs were shorter than in ward-based nurses, with a substantial number effectively occurring with new contacts. Institutional effects significant on univariate analyses were much reduced and non-significant after adjusting for confounding by HCW type.

CONCLUSION

HCWs' contacts differ substantially from those of community-based working adults. HCWs may thus be at higher risk of acquiring and spreading contact-transmissible and respiratory infections due to the nature of their work. Whereas total number of contacts was fairly similar between HCW types, the characteristics of their contacts differed substantively.

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.

Influenza Vaccination of Healthcare Workers: Critical Analysis of the Evidence for Patient Benefit Underpinning Policies of Enforcement

BACKGROUND

Four cluster randomized controlled trials (cRCTs) conducted in long-term care facilities (LTCFs) have reported reductions in patient risk through increased healthcare worker (HCW) influenza vaccination. This evidence has led to expansive policies of enforcement that include all staff of acute care hospitals and other healthcare settings beyond LTCFs. We critique and quantify the cRCT evidence for indirect patient benefit underpinning policies of mandatory HCW influenza vaccination.

METHODS

Plausibility of the four cRCT findings attributing indirect patient benefits to HCW influenza vaccination was assessed by comparing percentage reductions in patient risk reported by the cRCTs to predicted values. Plausibly predicted values were derived according to the basic mathematical principle of dilution, taking into account HCW influenza vaccine coverage and the specificity of patient outcomes for influenza. Accordingly, predicted values were calculated as a function of relevant compound probabilities including vaccine efficacy (ranging 40-60% in HCWs and favourably assuming the same indirect protection conferred through them to patients) × change in proportionate HCW influenza vaccine coverage (as reported by each cRCT) × percentage of a given patient outcome (e.g. influenza-like illness (ILI) or all-cause mortality) plausibly due to influenza virus. The number needed to vaccinate (NNV) for HCWs to indirectly prevent patient death was recalibrated based on real patient data of hospital-acquired influenza, with adjustment for potential under-detection (5.2-fold), and using favourable assumptions of HCW-attributable risk (ranging 60-80%).

RESULTS

In attributing patient benefit to increased HCW influenza vaccine coverage, each cRCT was found to violate the basic mathematical principle of dilution by reporting greater percentage reductions with less influenza-specific patient outcomes (i.e., all-cause mortality > ILI > laboratory-confirmed influenza) and/or patient mortality reductions exceeding even favourably-derived predicted values by at least 6- to 15-fold. If extrapolated to all LTCF and hospital staff in the United States, the prior cRCT-claimed NNV of 8 would implausibly mean >200,000 and >675,000 patient deaths, respectively, could be prevented annually by HCW influenza vaccination, inconceivably exceeding total US population mortality estimates due to seasonal influenza each year, or during the 1918 pandemic, respectively. More realistic recalibration based on actual patient data instead shows that at least 6000 to 32,000 hospital workers would need to be vaccinated before a single patient death could potentially be averted.

CONCLUSIONS

The four cRCTs underpinning policies of enforced HCW influenza vaccination attribute implausibly large reductions in patient risk to HCW vaccination, casting serious doubts on their validity. The impression that unvaccinated HCWs place their patients at great influenza peril is exaggerated. Instead, the HCW-attributable risk and vaccine-preventable fraction both remain unknown and the NNV to achieve patient benefit still requires better understanding. Although current scientific data are inadequate to support the ethical implementation of enforced HCW influenza vaccination, they do not refute approaches to support voluntary vaccination or other more broadly protective practices, such as staying home or masking when acutely ill.

Potential Ceiling Effect of Healthcare Worker Influenza Vaccination on the Incidence of Nosocomial Influenza Infection

OBJECTIVE To evaluate the effect of healthcare worker (HCW) influenza vaccination on the incidence of nosocomial influenza DESIGN Retrospective cross-sectional study SETTING A 550-bed tertiary-care academic medical center METHODS All admitted patients with a direct fluorescent antibody (DFA) or polymerase chain reaction (PCR) assay positive for influenza ordered between October 1 and May 31 from 2010 to 2015 were eligible for inclusion. Nosocomial influenza was defined as a positive influenza test collected ≥48 hours after admission in patients without influenza-like illness present within 24 hours of admission. Relative nosocomial influenza frequency was calculated by dividing the number of nosocomial cases by the total number of admitted patients with influenza for each season. A univariate logistic regression was used to determine the association between HCW influenza vaccination coverage and nosocomial influenza. RESULTS Over 5 seasons, 533 patients had positive influenza tests during their hospitalization; 29 of these patients (5.4%) acquired influenza during their hospitalization. HCW vaccination coverage increased over the 5 seasons from 47% to 90% (P<.001). Despite an initial decrease in relative nosocomial influenza frequency during the first year (9% to 4.9%), subsequent seasons failed to show an additional decrease in nosocomial infections (4.3%, 5.2%, and 4.8%, respectively); the overall decrease in nosocomial influenza from the first season to the final season was not significant (P=.282). No association was detected between HCW vaccination coverage and nosocomial influenza (odds ratio [OR], 0.990; 95% confidence interval [CI], 0.970-1.011). CONCLUSION HCW vaccination >50% may not have a significant effect on nosocomial influenza. Infect Control Hosp Epidemiol 2016;37:840-844.

Implementing a declination form programme to improve influenza vaccine uptake by staff in Department of Veterans Affairs spinal cord injury centres: a pilot study

BACKGROUND

Individuals with spinal cord injuries and disorders are at high risk for respiratory and influenza-related complications after developing influenza. These individuals often have frequent contact with the healthcare system. Vaccination rates in healthcare workers at Department of Veterans Affairs (VA) spinal cord injury (SCI) centres have been approximately 50% for several years. Efforts are needed to increase vaccination uptake among SCI HCWs. Declination form programmes (DFPs) in combination with other strategies have resulted in significant increases in influenza vaccination uptake in HCWs.

AIM

Use of external and internal facilitation including local teams and consensus processes to pilot a DFP in two VA SCI centres and evaluate factors influencing implementation.

METHODS

Implementation meetings and a consensus-building process with leadership and implementation team members were conducted, along with semi-structured post-implementation interviews with members of each implementation team (N = 7).

FINDINGS

The DFP was well accepted and easy to use. Leadership was a key facilitator for DFP implementation. Barriers included difficulty communicating with HCWs working during early/late shifts. Participation was 100% at Site 1 and 48% at Site 2.

CONCLUSION

Use of local teams and consensus to identify strategies to implement a DFP is feasible and effective for achieving moderate-to-high levels of participation in the programme.

A new approach to improving healthcare personnel influenza immunization programs: a randomized controlled trial

Background

Healthcare personnel influenza immunization rates remain sub-optimal. Following multiple studies and expert consultations, the “Successful Influenza Immunization Programs for Healthcare Personnel: A Guide for Program Planners” was produced. This trial assessed the impact of the Guide with facilitation in improving healthcare personnel influenza immunization rates in Canadian healthcare organizations.

Methods

A sample of 26 healthcare organizations across six Canadian provinces (ON, MB, NS, BC, SK, NL) was randomized to Intervention (n=13) or Control groups (n=13). Baseline influenza immunization rates were obtained for 2008–2009; the study groups were followed over two subsequent influenza seasons. The Intervention group received the Guide, facilitation support through workshops for managers and ongoing support. The Control groups conducted programs as usual. The Groups were compared using their reported influenza healthcare personnel influenza immunization rates and scores from a program assessment questionnaire.

Findings

Twenty-six organizations agreed to participate. 35% (9/26) of sites were acute care hospitals, 19% (5/26) continuing care, long-term care organizations or nursing homes, and 46% (12/26) were mixed acute care hospitals and long-term care or regional health authorities. The median rate of influenza immunization among healthcare personnel for the Intervention group was 43%, 44%, and 51% at three points in time respectively, and in the Control group: 62%, 57%, and 55% respectively. No significant differences were observed between the groups at the three points in time. However, there was a 7% increase in the median rates between the Baseline Year and Year Two in the Intervention group, and a 6% decrease in the Control group over the same time period, which was statistically significant (0.071 versus -0.058, p < 0.001).

Interpretation

This pragmatic randomized trial of the Guide with facilitation of its implementation improved healthcare personnel immunization rates, but these rates continued to be sub-optimal and below rates achievable in programs requiring personnel to be immunized.

Trial Registration

ClinicalTrials.gov NCT01207518

Revised SHEA Position Paper: Influenza Vaccination of Healthcare Personnel

Executive Summary

This document serves as an update and companion piece to the 2005 Society for Healthcare Epidemiology of America (SHEA) Position Paper entitled “Influenza Vaccination of Healthcare Workers and Vaccine Allocation for Healthcare Workers During Vaccine Shortages.” In large part, the discussion about the rationale for influenza vaccination of healthcare personnel (HCP), the strategies designed to improve influenza vaccination rates in this population, and the recommendations made in the 2005 paper still stand. This position paper notes new evidence released since publication of the 2005 paper and strengthens SHEA's position on the importance of influenza vaccination of HCP. This document does not discuss vaccine allocation during times of vaccine shortage, because the 2005 SHEA Position Paper still serves as the Society's official statement on that issue.

Improving Influenza Vaccination of Healthcare Workers by Means of Quality Improvement Tools

For a healthcare worker seasonal influenza vaccination quality improvement project, interventions included support of leadership, distribution of vaccine kits, grand rounds, an influenza website, a Screensaver, e-mails, phone messages, and audit feedback. Vaccination rates increased from 58.8% to 76.6% (P < .01). Quality improvement increased the voluntary vaccination rate but did not achieve a rate more than 80%.

Technical guidelines for the application of seasonal influenza vaccine in China (2014-2015)

Influenza, caused by the influenza virus, is a respiratory infectious disease that can severely affect human health. Influenza viruses undergo frequent antigenic changes, thus could spread quickly. Influenza causes seasonal epidemics and outbreaks in public gatherings such as schools, kindergartens, and nursing homes. Certain populations are at risk for severe illness from influenza, including pregnant women, young children, the elderly, and people in any ages with certain chronic diseases.

Sociocognitive predictors of the intention of healthcare workers to receive the influenza vaccine in Belgian, Dutch and German hospital settings

BACKGROUND

Influenza vaccination of healthcare workers (HCWs) is recommended to prevent the transmission of influenza to vulnerable patients. Nevertheless, vaccination coverage rates of HCWs in European countries have been low.

AIM

To investigate the relative and combined strength of sociocognitive variables, from past research, theory and a qualitative study, in explaining the motivation of HCWs to receive the influenza vaccine.

METHODS

An anonymous, online questionnaire was distributed among HCWs in hospital settings in Belgium, Germany and the Netherlands between February and April 2013.

FINDINGS

Attitude and past vaccination uptake explained a considerable amount of variance in the intention of HCWs to receive the influenza vaccine. Moreover, low perceived social norms, omission bias, low moral norms, being older, having no patient contact, and being Belgian or Dutch (compared with German) increased the probability of having no intention to receive the influenza vaccine compared with being undecided about vaccination. High intention to receive the influenza vaccine was shown to be more likely than being undecided about vaccination when HCWs had high perceived susceptibility of contracting influenza, low naturalistic views, and lower motivation to receive the vaccine solely for self-protection.

CONCLUSION

Country-specific interventions and a focus on different sociocognitive variables depending on the intention/lack of intention of HCWs to receive the influenza vaccine may be beneficial to promote vaccination uptake.

Mandatory influenza vaccination for health care workers as the new standard of care: a matter of patient safety and nonmaleficent practice

A growing body of literature defends the efficacy of seasonal influenza vaccination for health care workers in reducing the mortality of hospitalized patients. I review the evidence concerning influenza vaccination, concluding that universal vaccination of health care workers against influenza should be considered standard patient care and that nonvaccination represents maleficent care. I further argue that the ethical responsibility to ensure universal vaccination of staff against seasonal influenza lies not only with individual health care providers but with each individual health care institution.

Mandatory seasonal influenza vaccination or masking of British Columbia health care workers: Year 1

OBJECTIVE

The Influenza Prevention Policy ("the Policy") aims to increase seasonal influenza vaccination coverage among British Columbia (BC) health care workers (HCWs).

PARTICIPANTS

HCWs who work in publicly funded facilities and attend patient care areas.

SETTING

The Policy was announced in August 2012 and took effect province-wide during the 2012/13 flu season.

INTERVENTION

BC HCWs are required to receive seasonal influenza vaccination by the start of the flu season (December 1) or wear a mask while at work until the flu season ends (March 30). Vaccinated HCWs need to wear a green dot on their identification tag. HCWs are expected to report noncompliant coworkers. As initially proposed, continued noncompliance with the Policy could result in termination of employment (ultimately this component was put in abeyance).

OUTCOME

For the 2012/13 flu season, 74% of HCWs (35,889/48,818) at acute care facilities received influenza vaccination compared with 40% (23,375/58,212) in 2011/12 (difference in proportion=0.33, 95% confidence interval [CI]: 0.33-0.34, p<0.001). Similarly, staff vaccination rates at residential care facilities increased from 57% (21,535/37,700) for the 2011/12 flu season to 75% (27,617/36,620) in 2012/13 (difference in proportion=0.18, 95% CI: 0.18-0.19, p<0.001). Health care unions claimed that the Policy was coercive, and they launched an unsuccessful grievance with the BC Labour Relations Board.

CONCLUSION

Implementation of the Policy was associated with increased HCW vaccination; the Policy was upheld by an independent arbitrator. Further research is required to correlate HCW vaccination coverage rates with changes in influenza incidence and its complications. Continued stakeholder engagement is vital to achieve a collaborative decision-making process.

Vaccination policies for healthcare workers in Europe

Health-care workers (HCWs) are at increased risk for acquisition of vaccine-preventable diseases (VPDs) and vaccination is justified in order to protect them from occupational exposure and to prevent the spread of VPDs that pose a threat to susceptible patients. Review of European vaccination policies for HCWs revealed significant differences between countries in terms of recommended vaccines, implementation frame (mandatory or recommendation), target HCW groups and health-care settings. Further, the few published studies available identified indicate significant immunity gaps among HCWs against VPDs in Europe. In order to achieve higher vaccination coverage against VPDs stronger recommendations are needed. The issue of mandatory vaccination should be considered for diseases that can be transmitted to susceptible patients (influenza, measles, mumps, rubella, hepatitis B, pertussis, varicella). The acceptance of vaccinations and of mandatory vaccinations by HCWs is a challenge and appears to be VPD-specific.

Effect of influenza vaccination of healthcare personnel on morbidity and mortality among patients: systematic review and grading of evidence

BACKGROUND

Influenza vaccination of healthcare personnel (HCP) is recommended in >40 countries. However, there is controversy surrounding the evidence that HCP vaccination reduces morbidity and mortality among patients. Key factors for developing evidence-based recommendations include quality of evidence, balance of benefits and harms, and values and preferences.

METHODS

We conducted a systematic review of randomized trials, cohort studies, and case-control studies published through June 2012 to evaluate the effect of HCP influenza vaccination on mortality, hospitalization, and influenza cases in patients of healthcare facilities. We pooled trial results using meta-analysis and assessed evidence quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

We identified 4 cluster randomized trials and 4 observational studies conducted in long-term care or hospital settings. Pooled risk ratios across trials for all-cause mortality and influenza-like illness were 0.71 (95% confidence interval [CI], .59-.85) and 0.58 (95% CI, .46-.73), respectively; pooled estimates for all-cause hospitalization and laboratory-confirmed influenza were not statistically significant. The cohort and case-control studies indicated significant protective associations for influenza-like illness and laboratory-confirmed influenza. No studies reported harms to patients. Using GRADE, the quality of the evidence for the effect of HCP vaccination on mortality and influenza cases in patients was moderate and low, respectively. The evidence quality for the effect of HCP vaccination on patient hospitalization was low. The overall evidence quality was moderate.

CONCLUSIONS

The quality of evidence is higher for mortality than for other outcomes. HCP influenza vaccination can enhance patient safety.

Modelling the transmission of healthcare associated infections: a systematic review

Background

Dynamic transmission models are increasingly being used to improve our understanding of the epidemiology of healthcare-associated infections (HCAI). However, there has been no recent comprehensive review of this emerging field. This paper summarises how mathematical models have informed the field of HCAI and how methods have developed over time.

Methods

MEDLINE, EMBASE, Scopus, CINAHL plus and Global Health databases were systematically searched for dynamic mathematical models of HCAI transmission and/or the dynamics of antimicrobial resistance in healthcare settings.

Results

In total, 96 papers met the eligibility criteria. The main research themes considered were evaluation of infection control effectiveness (64%), variability in transmission routes (7%), the impact of movement patterns between healthcare institutes (5%), the development of antimicrobial resistance (3%), and strain competitiveness or co-colonisation with different strains (3%). Methicillin-resistant Staphylococcus aureus was the most commonly modelled HCAI (34%), followed by vancomycin resistant enterococci (16%). Other common HCAIs, e.g. Clostridum difficile, were rarely investigated (3%). Very few models have been published on HCAI from low or middle-income countries.

The first HCAI model has looked at antimicrobial resistance in hospital settings using compartmental deterministic approaches. Stochastic models (which include the role of chance in the transmission process) are becoming increasingly common. Model calibration (inference of unknown parameters by fitting models to data) and sensitivity analysis are comparatively uncommon, occurring in 35% and 36% of studies respectively, but their application is increasing. Only 5% of models compared their predictions to external data.

Conclusions

Transmission models have been used to understand complex systems and to predict the impact of control policies. Methods have generally improved, with an increased use of stochastic models, and more advanced methods for formal model fitting and sensitivity analyses. Insights gained from these models could be broadened to a wider range of pathogens and settings. Improvements in the availability of data and statistical methods could enhance the predictive ability of models.

Hospital-based cluster randomised controlled trial to assess effects of a multi-faceted programme on influenza vaccine coverage among hospital healthcare workers and nosocomial influenza in the Netherlands, 2009 to 2011

Nosocomial influenza is a large burden in hospitals. Despite recommendations from the World Health Organization to vaccinate healthcare workers against influenza, vaccine uptake remains low in most European countries. We performed a pragmatic cluster randomised controlled trial in order to assess the effects of implementing a multi-faceted influenza immunisation programme on vaccine coverage in hospital healthcare workers (HCWs) and on in-patient morbidity. We included hospital HCWs of three intervention and three control University Medical Centers (UMCs), and 3,367 patients. An implementation programme was offered to the intervention UMCs to assess the effects on both vaccine uptake among hospital staff and patient morbidity. In 2009/10, the coverage of seasonal, the first and second dose of pandemic influenza vaccine as well as seasonal vaccine in 2010/11 was higher in intervention UMCs than control UMCs (all p<0.05). At the internal medicine departments of the intervention group with higher vaccine coverage compared to the control group, nosocomial influenza and/or pneumonia was recorded in 3.9% and 9.7% of patients of intervention and control UMCs, respectively (p=0.015). Though potential bias could not be completely ruled out, an increase in vaccine coverage was associated with decreased patient in-hospital morbidity from influenza and/or pneumonia.

Can we achieve high uptakes of influenza vaccination of healthcare workers in hospitals? A cross-sectional survey of acute NHS trusts in England

It is unknown which intervention strategies are used or effective to increase influenza vaccine uptake by healthcare workers (HCWs) in acute hospitals in England. We undertook a survey in acute hospitals, described strategies employed from 2008 to 2012 and used multivariable binomial regression to identify those effective. Eighty out of 166 trusts responded and reported 25 strategies. Every intervention showed increased use: peer vaccination from 3·8% to 38·8% (+921%); educational DVDs from 3·8% to 22·5% (+492%); Twitter from 2·5% to 12·5% (+400%) and Facebook from 1·3% to 6·3% (+384%). Peer vaccination increased uptake by 7·3% [95% confidence interval (CI) 1·1–13·6, P = 0·02] overall; educational DVDs by 9·7% overall (95% CI 1·8–17·6, P = 0·02), 11·9% in non-doctor, non-nurse HCWs (95% CI 0·9–22·8, P = 0·03). For doctors, using a champion doctor increased uptake by 17·8% (95% CI 7·6–28·0, P < 0·01). No intervention increased uptake by nurses. Increasing uptake requires multi-intervention strategies targeted at different HCW groups.

A social network of hospital acquired infection built from electronic medical record data

OBJECTIVE

Social networks have been used in the study of outbreaks of infectious diseases, including in small group settings such as individual hospitals. Collecting the data needed to create such networks, however, can be time consuming, costly, and error prone. We sought to create a social network of hospital inpatients using electronic medical record (EMR) data already collected for other purposes, for use in simulating outbreaks of nosocomial infections.

MATERIALS AND METHODS

We used the EMR data warehouse of a tertiary academic hospital to model contact among inpatients. Patient-to-patient contact due to shared rooms was inferred from admission-discharge-transfer data, and contact with healthcare workers was inferred from clinical documents. Contacts were used to generate a social network, which was then used to conduct probabilistic simulations of nosocomial outbreaks of methicillin-resistant Staphylococcus aureus and influenza.

RESULTS

Simulations of infection transmission across the network reflected the staffing and patient flow practices of the hospital. Simulations modeling patient isolation, increased hand hygiene, and staff vaccination showed a decrease in the spread of infection.

DISCUSSION

We developed a method of generating a social network of hospital inpatients from EMR data. This method allows the derivation of networks that reflect the local hospital environment, obviate the need for simulated or manually collected data, and can be updated in near real time.

CONCLUSIONS

Inpatient social networks represent a novel secondary use of EMR data, and can be used to simulate nosocomial infections. Future work should focus on prospective validation of the simulations, and adapting such networks to other tasks.

Legal considerations surrounding mandatory influenza vaccination for healthcare workers in the United States

Recent years have brought increased focus on the desirability of vaccinating more healthcare workers against influenza. The concern that novel 2009 H1N1 influenza A would spark a particularly severe influenza season in 2009-2010 spurred several institutions and one state to institute mandatory vaccination policies for healthcare workers, and several new mandates have been introduced since then. Some healthcare workers, however, have voiced objections in the media and in legal proceedings. This paper reviews the characteristics of influenza and how it is transmitted in the healthcare setting; surveys possible constitutional, administrative, and common law arguments against mandates; assesses the viability of those arguments; and identifies potential new legal strategies to support influenza vaccine mandates. It is intended to assist those involved in the regulation and administration of public and private healthcare institutions who may be considering approaches to mandates but have concerns about legal challenges.

An ethical analysis of mandatory influenza vaccination of health care personnel: implementing fairly and balancing benefits and burdens

Health care institutions have paid increasing attention to preventing nosocomial transmission of influenza through vaccination of health care personnel. While multifaceted voluntary interventions have increased vaccination rates, proponents of mandatory programs contend the rates remain unacceptably low. Conventional bioethical analyses of mandatory programs are inadequate; they fail to account for the obligations of nonprofessional personnel or to justify the weights assigned to different ethical principles. Using an ethics framework for public health permits a fuller analysis. The framework's focus on fairness accentuates the potential differences between the risk of transmitting infection and employment status, and the need to equitably evaluate exemptions. The framework's emphasis on balancing benefits and burdens highlights the need to justify a specific goal and questions the need to exclude all nonmedical exemptions. While mandatory vaccination programs are justifiable, greater attention should be paid to their implementation.

Vaccination of health care workers to protect patients at increased risk for acute respiratory disease

Health care workers (HCWs) may transmit respiratory infection to patients. We assessed evidence for the effectiveness of vaccinating HCWs to provide indirect protection for patients at risk for severe or complicated disease after acute respiratory infection. We searched electronic health care databases and sources of gray literature by using a predefined strategy. Risk for bias was assessed by using validated tools, and results were synthesized by using a narrative approach. Seventeen of the 12,352 identified citations met the full inclusion criteria, and 3 additional articles were identified from reference or citation tracking. All considered influenza vaccination of HCWs, and most were conducted in long-term residential care settings. Consistency in the direction of effect was observed across several different outcome measures, suggesting a likely protective effect for patients in residential care settings. However, evidence was insufficient for us to confidently extrapolate this to other at-risk patient groups.

Influenza vaccination of healthcare workers in acute-care hospitals: a case-control study of its effect on hospital-acquired influenza among patients

BACKGROUND

In acute-care hospitals, no evidence of a protective effect of healthcare worker (HCW) vaccination on hospital-acquired influenza (HAI) in patients has been documented. Our study objective was to ascertain the effectiveness of influenza vaccination of HCW on HAI among patients.

METHODS

A nested case-control investigation was implemented in a prospective surveillance study of influenza-like illness (ILI) in a tertiary acute-care university hospital. Cases were patients with virologically-confirmed influenza occurring ≥ 72 h after admission, and controls were patients with ILI presenting during hospitalisation with negative influenza results after nasal swab testing. Four controls per case, matched per influenza season (2004-05, 2005-06 and 2006-07), were randomly selected. Univariate and multivariate conditional logistic regression models were fitted to assess factors associated with HAI among patients.

RESULTS

In total, among 55 patients analysed, 11 (20%) had laboratory-confirmed HAI. The median HCW vaccination rate in the units was 36%. The median proportion of vaccinated HCW in these units was 11.5% for cases vs. 36.1% for the controls (P = 0.11); 2 (20%) cases and 21 (48%) controls were vaccinated against influenza in the current season (P = 0.16). The proportion of ≥ 35% vaccinated HCW in short-stay units appeared to protect against HAI among patients (odds ratio = 0.07; 95% confidence interval 0.005-0.98), independently of patient age, influenza season and potential influenza source in the units.

CONCLUSIONS

Our observational study indicates a shielding effect of more than 35% of vaccinated HCW on HAI among patients in acute-care units. Investigations, such as controlled clinical trials, are needed to validate the benefits of HCW vaccination on HAI incidence in patients.

Influenza vaccination coverage among US nursing home nursing assistants: the role of working conditions

OBJECTIVES

To estimate influenza vaccination coverage among nursing assistants (NAs) working in US nursing homes, and to identify demographic and occupational predictors of vaccination status among NAs.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional analysis of data on 2873 NAs from the 2004 National Nursing Assistant Survey. Multivariable-adjusted vaccination coverage (prevalence) ratios for demographic and occupational characteristics were calculated using Poisson regression.

MEASUREMENTS

Outcome variable was NAs' influenza vaccination status, yes or no, based on the question, "During the past 12 months, did you receive a flu shot?"

RESULTS

Coverage for all NAs working in US nursing homes was estimated to be 37.1%. NAs 45 or older were more likely to be vaccinated than younger NAs (prevalence ratio [PR] = 1.23, 95% confidence interval [CI]: 1.07-1.41). Significant negative associations with vaccination status were found for NAs who were non-Hispanic blacks (PR = 0.82, 95% CI: 0.70-0.97), disagreed that they were respected/rewarded for their work (PR = 0.85, 95% CI: 0.71-1.00), worked at for-profit facilities (PR = 0.83, 95% CI: 0.72-0.95), and reported receiving fewer than 7 of 15 nonwage job benefits (PR = 0.77, 95% CI: 0.67-0.90).

CONCLUSION

Influenza coverage among nursing home NAs appears to be similar to nationally reported coverage estimates among health care providers in the United States in general. In addition to individual characteristics, occupational characteristics reflective of working conditions are associated with vaccination status among NAs, suggesting that further research into these types of associations may be useful in identifying which institutions may benefit from outreach efforts and types of interventions to increase vaccination coverage.

Prioritizing healthcare worker vaccinations on the basis of social network analysis

OBJECTIVE

To use social network analysis to design more effective strategies for vaccinating healthcare workers against influenza.

DESIGN

An agent-based simulation.

SETTING

A simulation based on a 700-bed hospital.

METHODS

We first observed human contacts (defined as approach within approximately 0.9 m) performed by 15 categories of healthcare workers (eg, floor nurses, intensive care unit nurses, staff physicians, phlebotomists, and respiratory therapists). We then constructed a series of contact graphs to represent the social network of the hospital and used these graphs to run agent-based simulations to model the spread of influenza. A targeted vaccination strategy that preferentially vaccinated more "connected" healthcare workers was compared with other vaccination strategies during simulations with various base vaccination rates, vaccine effectiveness, probability of transmission, duration of infection, and patient length of stay.

RESULTS

We recorded 6,654 contacts by 148 workers during 606 hours of observations from January through December 2006. Unit clerks, X-ray technicians, residents and fellows, transporters, and physical and occupational therapists had the most contacts. When repeated contacts with the same individual were excluded, transporters, unit clerks, X-ray technicians, physical and occupational therapists, and social workers had the most contacts. Preferentially vaccinating healthcare workers in more connected job categories yielded a substantially lower attack rate and fewer infections than a random vaccination strategy for all simulation parameters.

CONCLUSIONS

Social network models can be used to derive more effective vaccination policies, which are crucial during vaccine shortages or in facilities with low vaccination rates. Local vaccination priorities can be determined in any healthcare facility with only a modest investment in collection of observational data on different types of healthcare workers. Our findings and methods (ie, social network analysis and computational simulation) have implications for the design of effective interventions to control a broad range of healthcare-associated infections.

Staff flu vaccination: A patient safety necessity?

The nights are drawing in, winter is fast approaching, and occupational health departments are already beginning staff flu immunization programmes. Vaccinated staff protect both vaccinated and unvaccinated patients from flu (van den Dool et al, 2008; 2009), and improve staff health, reduce sick leave, as well as set the public a good example.

Self-reported anticipated compliance with physician advice to stay home during pandemic (H1N1) 2009: results from the 2009 Queensland Social Survey

Background

One strategy available to public health officials during a pandemic is physician recommendations for isolation of infected individuals. This study was undertaken during the height of the Australian pandemic (H1N1) 2009 outbreak to measure self-reported willingness to comply with physician recommendations to stay home for seven days, and to compare responses for the current strain of pandemic influenza, avian influenza, seasonal influenza, and the common cold.

Methods

Data were collected as part of the Queensland Social Survey (QSS) 2009, which consisted of a standardized introduction, 37 demographic questions, and research questions incorporated through a cost-sharing arrangement. Four questions related to respondents' anticipated compliance with a physician's advice to stay home if they had a common cold, seasonal influenza, pandemic (H1N1) 2009 influenza or avian influenza were incorporated into QSS 2009, with responses recorded using a balanced Likert scale ranging from "very unlikely" to "very likely." Discordance between responses for different diseases was analysed using McNemar's test. Associations between demographic variables and anticipated compliance were analysed using Pearson's chi-square or chi-square for linear-by-linear association, and confirmed using multivariate logistic regression; p < 0.05 was used to establish statistical significance.

Results

Self-reported anticipated compliance increased from 59.9% for the common cold to 71.3% for seasonal influenza (p < .001), and to 95.0% for pandemic (H1N1) 2009 influenza and 94.7% for avian influenza (p < 0.001 for both versus seasonal influenza). Anticipated compliance did not differ for pandemic (H1N1) 2009 and avian influenza (p = 0.815). Age and sex were both associated with anticipated compliance in the setting of seasonal influenza and the common cold. Notably, 27.1% of health and community service workers would not comply with physician advice to stay home for seasonal influenza.

Conclusions

Ninety-five percent of people report they would comply with a physicians' advice to stay home for seven days if they are diagnosed with pandemic (H1N1) 2009 or avian influenza, but only 71% can be expected to comply in the setting of seasonal influenza and fewer still can be expected to comply if they are diagnosed with a common cold. Sub-populations that might be worthwhile targets for public health messages aimed at increasing the rate of self-imposed isolation for seasonal influenza include males, younger people, and healthcare workers.