The social network around influenza vaccination in health care workers: a cross-sectional study

Background

Influenza vaccination coverage remains low among health care workers (HCWs) in many health facilities. This study describes the social network defined by HCWs’ conversations around an influenza vaccination campaign in order to describe the role played by vaccination behavior and other HCW characteristics in the configuration of the links among subjects.

Methods

This study used cross-sectional data from 235 HCWs interviewed after the 2010/2011 influenza vaccination campaign at the Hospital Clinic of Barcelona (HCB), Spain. The study asked: “Who did you talk to or share some activity with respect to the seasonal vaccination campaign?” Variables studied included sociodemographic characteristics and reported conversations among HCWs during the influenza campaign. Exponential random graph models (ERGM) were used to assess the role of shared characteristics (homophily) and individual characteristics in the social network around the influenza vaccination campaign.

Results

Links were more likely between HCWs who shared the same professional category (OR 3.13, 95% CI?=?2.61–3.75), sex (OR 1.34, 95% CI?=?1.09–1.62), age (OR 0.7, 95% CI?=?0.63–0.78 per decade of difference), and department (OR 11.35, 95% CI?=?8.17–15.64), but not between HCWs who shared the same vaccination behavior (OR 1.02, 95% CI?=?0.86–1.22). Older (OR 1.26, 95% CI?=?1.14–1.39 per extra decade of HCW) and vaccinated (OR 1.32, 95% CI?=?1.09–1.62) HCWs were more likely to be named.

Conclusions

This study finds that there is no homophily by vaccination status in whom HCWs speak to or interact with about a workplace vaccination promotion campaign. This result highlights the relevance of social network analysis in the planning of health promotion interventions.

     

Individual and collective considerations in public health: influenza vaccination in nursing homes

Many nursing homes have an influenza vaccination policy in which it is assumed that express (proxy) consent is not necessary. Tacit consent procedures are more efficient if one aims at high vaccination rates. In this paper I focus on incompetent residents and proxy consent. Tacit proxy consent for vaccination implies a deviance of standard proxy consent requirements. I analyse several arguments that may possibly support such a deviance. The primary reason to offer influenza vaccination is that vaccinated persons have a significantly reduced risk of getting the flu. This reason however cannot support the assumption that each nursing home resident is 'better off ' if she is vaccinated. Neither can it support tacit proxy consent policies. More promising are arguments that take the collective nature of infectious diseases into account. A potentially strong, but ultimately insufficient, argument for non-express consent is that vaccination contributes to prevention of harm to others. Other arguments emphasise the importance of group protection: herd immunity. I discuss three collective reasons for aiming at herd immunity: solidarity, a common interest in reducing the risk of illness, and a common interest in the prevention of an influenza outbreak. The latter argument appears to be most important. An outbreak is not just detrimental to the health of residents; it is detrimental to their everyday social life as well. Outbreaks can be seen as a collective evil. My analysis shows that there are valid (though not necessarily sufficient) moral arguments for a tacit proxy consent policy.     

Vaccination behaviour influences self-report of influenza vaccination status: a cross-sectional study among health care workers

Background

Published influenza vaccination coverage in health care workers (HCW) are calculated using two sources: self-report and vaccination records. The objective of this study was to determine whether self-report is a good proxy for recorded vaccination in HCW, as the degree of the relationship is not known, and whether vaccine behaviour influences self-reporting.

Methods

A cross-sectional study was conducted using a self-administered survey during September 2010. Considering the vaccination record as the gold standard of vaccination, the properties of self-report as a proxy of the record (sensitivity, specificity, positive predictive value, negative predictive value) were calculated. Concordance between the vaccination campaigns studied (2007–2010) was made using the Kappa index, and discordance was analyzed using McNemar’s test.

Results

248 HCW responded. The 95% confidence intervals of coverage according to the vaccination record and to self-report overlapped, except for 2007, and the Kappa index showed a substantial concordance, except for 2007. McNemar’s test suggested that differences between discordant cases were not due to chance and it was found that the proportion of unvaccinated discordant cases was higher than that of vaccinated discordant cases.

Conclusions

In our study population, self-reported influenza vaccination coverage in HCW in the previous two years is a good proxy of the vaccination record. However, vaccination behaviour influences the self-report and explains a trend to overestimate coverage in self-reporting compared to the vaccination record. The sources of coverage should be taken into account whenever comparisons are made.     

Fighting misconceptions to improve compliance with influenza vaccination among health care workers: an educational project

The compliance with influenza vaccination is poor among health care workers (HCWs) due to misconceptions about safety and effectiveness of influenza vaccine. We proposed an educational prospective study to demonstrate to HCWs that influenza vaccine is safe and that other respiratory viruses (RV) are the cause of respiratory symptoms in the months following influenza vaccination. 398 HCWs were surveyed for adverse events (AE) occurring within 48 h of vaccination. AE were reported by 30% of the HCWs. No severe AE was observed. A subset of 337 HCWs was followed up during four months, twice a week, for the detection of respiratory symptoms. RV was diagnosed by direct immunofluorescent assay (DFA) and real time PCR in symptomatic HCWs. Influenza A was detected in five episodes of respiratory symptoms (5.3%) and other RV in 26 (27.9%) episodes. The incidence density of influenza and other RV was 4.3 and 10.8 episodes per 100 HCW-month, respectively. The educational nature of the present study may persuade HCWs to develop a more positive attitude to influenza vaccination.     

Seasonal influenza vaccination campaigns for health care personnel: systematic review

Background

In Canada, vaccination coverage for seasonal influenza among health care personnel remains below 50%. The objective of this review was to determine which seasonal influenza vaccination campaign or campaign components in health care settings were significantly associated with increases in influenza vaccination among staff.

Methods

We identified articles in eight electronic databases and included randomized controlled trials, controlled before-and-after studies and studies with interrupted time series designs in our review. Two reviewers independently abstracted the data and assessed the risk of biases. We calculated risk ratios and 95% confidence intervals for randomized controlled trials and controlled before-and-after studies and described interrupted time series studies.

Results

We identified 99 studies evaluating influenza vaccination campaigns for health care workers, but only 12 of the studies were eligible for review. In nonhospital health care settings, including long-term care facilities, campaigns with a greater variety of components (including education or promotion, better access to vaccines, legislation or regulation and/or role models) were associated with higher risk ratios (i.e, favouring the intervention group). Within hospital settings, the results reported for various types of campaigns were mixed. Many of the criteria for assessing risk of bias were not reported.

Interpretation

Campaigns involving only education or promotion resulted in minimal changes in vaccination rates. Further studies are needed to determine the appropriate components and combinations of components in influenza vaccination campaigns for health care personnel.Health care personnel can act as vectors of influenza and may transmit the disease to patients who are at risk for influenza-related complications or death.¹ A Cochrane review² of three studies showed that vaccination of health care personnel, combined with vaccination of patients, was 86% efficacious (95% confidence interval [CI] 40%–97%) in preventing influenza-like illnesses among elderly patients. It is recommended that all health care personnel (i.e., minimum 90% coverage) receive the seasonal influenza vaccine for protection from the virus.³Rates of vaccination against seasonal influenza among health care personnel are often below targeted levels and vary across health care organizations in Canada and internationally. In 2003, vaccination coverage was 46% among Canadians employed in ambulatory care settings, hospitals and long-term care facilities.⁴ In a survey of Canadian long-term care facilities, the average vaccination rate among workers was 35%.⁵ Similarly, in the United States, vaccination coverage for health care personnel was about 40%,⁶ and in European countries, reported vaccine uptake has ranged from 14% to 48%.⁷The Canadian National Advisory Committee on Immunization encourages all organizations to actively promote the influenza vaccine and to provide education aimed at health care personnel.³ The US Healthcare Infection Control Practices Advisory Committee and the Advisory Committee on Immunization Practices have recommended that all organizations employing health care personnel use evidence-based approaches that may overcome barriers to vaccine uptake as part of their influenza vaccination campaigns.⁶ These two committees identified five categories of components of influenza vaccination campaigns aimed at improving immunization rates among health care personnel (6

Behind the screens: care staff observations on delivery of oral health care in nursing homes

Objective: To identify qualitatively carer staff attitudes, practices and clinical comments related to oral health care of functionally dependent nursing home clients. Design: Open-ended questions included in a longer quantitative questionnaire. Setting: 22 randomly selected nursing homes in the Bristol area. Subjects: 416 carers employed in these homes. Results: The majority of carers thought that clients had a right to good oral health, accepted the carers' role in helping clients with oral and denture hygiene, but recognised that oral health care provision was deficient. However, some carers believed oral health care to be solely the clients' responsibility despite high disability levels. Main barriers to providing oral health care were low prioritisation of oral health by nursing management, lack of co-operation from cognitively impaired clients, and lack of training. Carers were critical of homes' lack of arrangements for routine professional dental cheeks, lack of commitment to staff training, low standards of oral health care by colleagues, and lack of provision of oral hygiene aids and cleansing materials for clients. Many responses indicated ways in which nursing home oral health care could be improved. Carers reported contrasting experiences of dental treatment, and deplored recent decreased availability of subsidised dental care. Conclusions: Carers' generally positive attitudes towards clients' oral health care should encourage health educators. Insights gained from qualitative data can help to identify the less obvious causes for poor oral care delivery, which can then be addressed in education and training initiatives in nursing home settings.     

The role of health care workers and antiviral drugs in the control of pandemic influenza

Until a vaccine against the new strain becomes available, the response to newly emerged pandemic influenza will consist of the use of antiviral drugs and measures that limit exposure to infectious individuals. These first-line defence measures include isolating cases upon diagnosis, reducing close contacts, the use of personal protective equipment and hygiene, and using antiviral drugs for treatment and prophylaxis. There are significant 'costs' associated with control measures, so to justify such interventions it is important to assess their potential to reduce transmission. In this paper, we determine the effect that a number of different antiviral interventions have on the reproduction number of infectives and the probability that an imported infection fades out, and determine parameter scenarios for which these interventions are able to eliminate an emerging pandemic of influenza. We also assess the role that health care workers play in transmission and the extent to which providing them with antiviral prophylaxis and personal protective equipment modifies this role. Our results indicate that this class requires protection to avoid a greatly disproportionate contribution to early infective numbers, and for the maintenance of a stable health care system. Further, we show that the role children play in increasing transmission is moderate, in spite of closer mixing with other children.     

Cell adhesion heterogeneity reinforces tumour cell dissemination: novel insights from a mathematical model

Background

Cancer cell invasion, dissemination, and metastasis have been linked to an epithelial-mesenchymal transition (EMT) of individual tumour cells. During EMT, adhesion molecules like E-cadherin are downregulated and the decrease of cell-cell adhesion allows tumour cells to dissociate from the primary tumour mass. This complex process depends on intracellular cues that are subject to genetic and epigenetic variability, as well as extrinsic cues from the local environment resulting in a spatial heterogeneity in the adhesive phenotype of individual tumour cells. Here, we use a novel mathematical model to study how adhesion heterogeneity, influenced by intrinsic and extrinsic factors, affects the dissemination of tumour cells from an epithelial cell population. The model is a multiscale cellular automaton that couples intracellular adhesion receptor regulation with cell-cell adhesion.

Results

Simulations of our mathematical model indicate profound effects of adhesion heterogeneity on tumour cell dissemination. In particular, we show that a large variation of intracellular adhesion receptor concentrations in a cell population reinforces cell dissemination, regardless of extrinsic cues mediated through the local cell density. However, additional control of adhesion receptor concentration through the local cell density, which can be assumed in healthy cells, weakens the effect. Furthermore, we provide evidence that adhesion heterogeneity can explain the remarkable differences in adhesion receptor concentrations of epithelial and mesenchymal phenotypes observed during EMT and might drive early dissemination of tumour cells.

Conclusions

Our results suggest that adhesion heterogeneity may be a universal trigger to reinforce cell dissemination in epithelial cell populations. This effect can be at least partially compensated by a control of adhesion receptor regulation through neighbouring cells. Accordingly, our findings explain how both an increase in intra-tumour adhesion heterogeneity and the loss of control through the local environment can promote tumour cell dissemination.

Reviewers

This article was reviewed by Hanspeter Herzel, Thomas Dandekar and Marek Kimmel.

     

The oral health of individuals with dementia in nursing homes

Objective: To determine if moderate to severe dementia has an effect on the oral health of individuals resident in nursing homes. Background: A significant proportion of the elderly population lives in nursing homes and suffers from varying degrees of dementia. Dementia might affect an individual's ability to implement oral care. Previous work in this area has focused on individuals with mild dementia living in the community setting. Material and methods: Two matched cohorts of subjects resident in four nursing homes in Cheshire were recruited (n = 135). One cohort's subjects were deemed to have no or mild dementia, whereas the other cohort's subjects were deemed to have moderate to severe dementia. Oral parameters were scored, including Decayed, Missing, Filled Teeth (DMFT) scoring, dental deposit scoring, denture assessment and the noting of any other pathology. Results: There was a statistically significant difference in the relative level of dementia of the subjects between the two cohorts (p < 0.01, Student's t‐test). The DMFT scores were similar for both groups. The mean number (±SD) of decayed and missing teeth for the no/mild dementia group was 1.11 (±3.42) and 28.22 (±6.64), whilst that of the moderate/severe dementia cohort was 0.80 (±1.87) and 27.28 (±7.73), respectively. Eleven per cent of the moderate/severe dementia cohort wore an upper denture alone as compared with 16% in the no/mild dementia group. Conclusion: For individuals resident in nursing homes, moderate to severe dementia might have a deleterious effect on oral health. Further work in this area is required.     

Violence in the emergency department: a survey of health care workers

BACKGROUND: Violence in the workplace is an ill-defined and underreported concern for health care workers. The objectives of this study were to examine perceived levels of violence in the emergency department, to obtain health care workers'' definitions of violence, to determine the effect of violence on health care workers and to determine coping mechanisms and potential preventive strategies. METHODS: A retrospective written survey of all 163 emergency department employees working in 1996 at an urban inner-city tertiary care centre in Vancouver. The survey elicited demographic information, personal definition of violence, severity of violence, degree of stress as a result of violence and estimate of the number of encounters with violence in the workplace in 1996. The authors examined the effects of violence on job performance and job satisfaction, and reviewed coping and potential preventive strategies. RESULTS: Of the 163 staff, 106 (65%) completed the survey. A total of 68% (70/103) reported an increased frequency of violence over time, and 60% (64/106) reported an increased severity. Most of the respondents felt that violence included witnessing verbal abuse (76%) and witnessing physical threats or assaults (86%). Sixty respondents (57%) were physically assaulted in 1996. Overall, 51 respondents (48%) reported impaired job performance for the rest of the shift or the rest of the week after an incident of violence. Seventy-seven respondents (73%) were afraid of patients as a result of violence, almost half (49%) hid their identities from patients, and 78 (74%) had reduced job satisfaction. Over one-fourth of the respondents (27/101) took days off because of violence. Of the 18 respondents no longer working in the emergency department, 12 (67%) reported that they had left the job at least partly owing to violence. Twenty-four-hour security and a workshop on violence prevention strategies were felt to be the most useful potential interventions. Physical exercise, sleep and the company of family and friends were the most frequent coping strategies. INTERPRETATION: Violence in the emergency department is frequent and has a substantial effect on staff well-being and job satisfaction.     

Long-term care for the elderly. The future of nursing homes.

Continuing growth in the number of impaired elderly persons necessitates a continued reliance on nursing homes to care for at least those who are most impaired or most lacking in other supports, despite dissatisfaction over the quality of nursing home services and anxiety about the costs. Nursing home care now costs more than $30 billion annually, half of which comes from governmental sources. The Medicaid program, in particular, is central to all aspects of the nursing home industry. Private long-term care insurance is unlikely to solve the problem of nursing home financing. Rationalizing public expenditures will hinge critically on greater clarity as to just what roles nursing homes are expected to fulfill in the system of care, especially how they are supposed to relate to other services provided to Medicare beneficiaries.     

The evolutionary dynamics of receptor binding avidity in influenza A: a mathematical model for a new antigenic drift hypothesis

The most salient feature of influenza evolution in humans is its antigenic drift. This process is characterized by structural changes in the virus''s B-cell epitopes and ultimately results in the ability of the virus to evade immune recognition and thereby reinfect previously infected hosts. Until recently, amino acid substitutions in epitope regions of the viral haemagglutinin were thought to be positively selected for their ability to reduce antibody binding and therefore were thought to be responsible for driving antigenic drift. However, a recent hypothesis put forward by Hensley and co-workers posits that cellular receptor binding avidity is the dominant phenotype under selection, with antigenic drift being a side effect of these binding avidity changes. Here, we present a mathematical formulation of this new antigenic drift model and use it to show how rates of antigenic drift depend on epidemiological parameters. We further use the model to evaluate how two different vaccination strategies can impact antigenic drift rates and ultimately disease incidence levels. Finally, we discuss the assumptions present in the model formulation, predictions of the model, and future work that needs to be done to determine the consistency of this hypothesis with known patterns of influenza''s genetic and antigenic evolution.