Nosocomial Influenza Outbreaks Research Articles

Intention, Motivation, and Empowerment: Factors Associated with Seasonal Influenza Vaccination among Healthcare Workers (HCWs).

Vaccination against seasonal influenza has proven effective in preventing nosocomial influenza outbreaks among hospital patients and healthcare workers (HCWs). This study aims to explore the intention, motivation, and empowerment toward vaccination and vaccination advocacy as contributing factors for seasonal influenza vaccination in HCWs. A cross-sectional study in eight secondary hospitals in Greece was conducted from March to May 2022. An anonymous questionnaire was enclosed in an envelope and distributed to all participants, including questions on vaccine behavior and the MoVac-flu and MoVad scales. A total of 296 participants completed the questionnaire. In multivariate logistic regression models adjusted for potential confounders, increased age, intention score, MoVac-flu scale score, and the presence of chronic diseases were significant predictors of influenza vaccination this year, while increased age, intention score, and presence of chronic diseases were predictors of vaccination every year. Vaccination uptake is simultaneously affected by logical cognitive processes (intention), together with factors related to motivation and empowerment in distinct self-regulatory domains such as value, impact, knowledge, and autonomy. Interventions focused on these identified predictors may be used as a guide to increase HCWs' vaccination rates.

Multidisciplinary Response to Nosocomial Influenza

Background: Nosocomial influenza infections can be caused by direct patient-to-patient transmission, as well as bidirectionally between patient and healthcare workers (HCWs). Lapses in infection control practices (droplet precautions), and HCWs who come to work despite influenza-like illness (ILI, ie, “presenteeism”) can potentiate transmission. Cocirculation of >1 strain of influenza may complicate efforts to track infections. We describe a multidisciplinary response that helped control a late winter nosocomial influenza outbreak at a time when both influenza A/H3 and A/H1(2009) were prevalent in the community. Methods: Infection control practitioners detected a potential cluster of influenza A/H3 cases on an adult general medicine unit during the middle of March. The patients were spread out in nonadjacent rooms in a 30-bed unit, which suggested a possible common shared source. Further investigation revealed other potential clusters. Hospital incident command (HIC) was deployed to assess and respond to the outbreak; the incident commander was the chief medical officer (CMO) and the hospital epidemiologist was the subject matter expert. Other HIC roles were manned by nursing leadership, hospital administration, employee health, and the clinical laboratory. The group met at least daily (teleconference on weekends) until the extent of the outbreak was known and no new cases were identified. Results: A multipronged approach was used to control the outbreak. HCWs who reported to work with ILI symptoms were referred to employee health, tested with a PCR-based influenza screening panel, and sent home. Inpatients with ILI symptoms were tested with a comprehensive respiratory virus panel that could distinguish influenza A/H1(2009) from A/H3. Inpatients who were newly positive for influenza were evaluated to determine whether they were epidemiologically linked to an existing cluster, represented a new case of nosocomial acquisition, or were presumed to be community-acquired. The outbreak involved separate clusters caused by A/H3 and A/H1(2009) that affected 40 patients on 9 clinical units. Conclusions: A key component of the response was implementation of a local “mask rule”: all physicians, nurses, other employees, students, and visitors were required to wear surgical masks on affected floors regardless of their vaccination status. In addition, the hospital IT team developed a dynamic spreadsheet that listed information about all nosocomial cases (location, date of onset, etc), as well as ILI call-ins for HCWs. A password-protected version was posted on the hospital intranet and facilitated cohorting of infected patients. Additionally, it allowed timely discontinuation of the local mask rule on specific units, once 2 incubation periods concluded without new cases.Funding: NoneDisclosures: None

Nosocomial outbreak of influenza A H3N2 in an inpatient oncology unit related to health care workers presenting to work while ill

ObjectiveTo describe an outbreak of influenza A in an oncology unit, highlighting infection control methods implemented, and examining reasons health care workers (HCWs) present to work with influenza-like illness (ILI).MethodsConfirmed cases were defined by the presence of ILI and a positive nasopharyngeal polymerase chain reaction swab for influenza A H3. Probable cases were defined as exposed HCWs with ILI who were unavailable for polymerase chain reaction testing. Infection prevention measures included closing the ward for new admissions, oseltamivir prophylaxis for all exposed groups, and dismissal from work of HCWs with ILI until resolution of symptoms. An anonymous survey of the cases in our HCWs was conducted to better elucidate reasons behind presenteeism.ResultsOver the course of 8 days (November 16, 2017, to November 22, 2017), influenza was diagnosed in 7 of 10 inpatients on the oncology ward, 16 HCWs (14 confirmed, 2 probable), and 2 visitors. The suspected index case was an HCW. Of the surveyed HCWs, 64% presented to work despite feeling ill (ie, presenteeism). The most common reason was “sense of duty as a health care worker.”ConclusionsThis nosocomial outbreak of influenza highlights the challenges of protecting inpatients from viral respiratory tract infections. HCWs and patient visitors with ILI should avoid work or visiting until resolution of peak respiratory symptoms and adhere to strict respiratory etiquette.

Molecular characterization of a nosocomial outbreak of influenza B virus in an acute care hospital setting

SummaryAimTo describe a hospital outbreak of influenza B virus (InfB) infection during season 2015/2016 by combining clinical and epidemiological data with molecular methods.MethodsTwenty patients diagnosed with InfB from a hospital outbreak over a four-week-period were included. Nasopharyngeal samples (NPS) positive for InfB by multiplex real-time polymerase chain reaction were sent for lineage typing and whole genome sequencing (WGS). Medical records were reviewed retrospectively for data regarding patient characteristics, localization, exposure and outcome, and assembled into a timeline. In order to find possible connections to the hospital outbreak, all patients with a positive NPS for influenza from the region over an extended time period were also reviewed.FindingsAll 20 cases of InfB were of subtype B/Yamagata, and 17 of 20 patients could be linked to each other by either shared room or shared ward. WGS was successful or partially successful for 15 of the 17 viral isolates, and corroborated the epidemiological link supporting a close relationship. In the main affected ward, 19 of 75 inpatients were infected with InfB during the outbreak period, resulting in an attack rate of 25%. One probable case of influenza-related death was identified.ConclusionInfB may spread within an acute care hospital, and advanced molecular methods may facilitate assessment of the source and extent of the outbreak. A multi-faceted approach, including rapid diagnosis, early recognition of outbreak situations, simple rules for patient management and the use of regular infection control measures, may prevent nosocomial transmission of influenza virus.

Probable transmission routes of the influenza virus in a nosocomial outbreak.

Influenza is a long-standing public health concern, but its transmission remains poorly understood. To have a better knowledge of influenza transmission, we carried out a detailed modelling investigation in a nosocomial influenza outbreak in Hong Kong. We identified three hypothesised transmission modes between index patient and other inpatients based on the long-range airborne and fomite routes. We considered three kinds of healthcare workers' routine round pathways in 1140 scenarios with various values of important parameters. In each scenario, we used a multi-agent modelling framework to estimate the infection risk for each hypothesis and conducted least-squares fitting to evaluate the hypotheses by comparing the distribution of the infection risk with that of the attack rates. Amongst the hypotheses tested in the 1140 scenarios, the prediction of modes involving the long-range airborne route fit better with the attack rates, and that of the two-route transmission mode had the best fit, with the long-range airborne route contributing about 94% and the fomite route contributing 6% to the infections. Under the assumed conditions, the influenza virus was likely to have spread via a combined long-range airborne and fomite routes, with the former predominant and the latter negligible.

Haemagglutinin and neuraminidase sequencing delineate nosocomial influenza outbreaks with accuracy equivalent to whole genome sequencing

We describe haemagglutinin (HA) and neuraminidase (NA) sequencing in an apparent cross-site influenza A(H1N1) outbreak in renal transplant and haemodialysis patients, confirmed with whole genome sequencing (WGS). Isolates were sequenced from influenza positive individuals. Phylogenetic trees were constructed using HA and NA sequencing and subsequently WGS. Sequence data was analysed to determine genetic relatedness of viruses obtained from inpatient and outpatient cohorts and compared with epidemiological outbreak information. There were 6 patient cases of influenza in the inpatient renal ward cohort (associated with 3 deaths) and 9 patient cases in the outpatient haemodialysis unit cohort (no deaths). WGS confirmed clustered transmission of two genetically different influenza A(H1N1)pdm09 strains initially identified by analysis of HA and NA genes. WGS took longer, and in this case was not required to determine whether or not the two seemingly linked outbreaks were related. Rapid sequencing of HA and NA genes may be sufficient to aid early influenza outbreak investigation making it appealing for future outbreak investigation. However, as next generation sequencing becomes cheaper and more widely available and bioinformatics software is now freely accessible next generation whole genome analysis may increasingly become a valuable tool for real-time Influenza outbreak investigation.

Successful use of oseltamivir prophylaxis in managing a nosocomial outbreak of influenza A in a hematology and allogeneic stem cell transplant unit.

To describe a nosocomial outbreak of H1N1 influenza A in an inpatient hematology and allogeneic stem cell transplant unit and outcomes of universal oseltamivir prophylaxis. Medical records of all patients admitted to the unit were reviewed to define the nosocomial outbreak, commencing 1 week prior to the index case until 4 weeks following institution of oseltamivir prophylaxis. Timelines for clinical symptoms, viral spread, management, patient outcomes and follow up testing were constructed. All cases of influenza were confirmed on nasopharyngeal swabs and/or bronchoalveolar lavages collected for polymerase chain reaction testing. In addition to the index case, further 11 patients were diagnosed with influenza A during the outbreak. Six patients (50%) had influenza-like-illness, five (42%) had respiratory symptoms only and one (8%) was asymptomatic. In total, five patients died, including four (33%) patients who were admitted to intensive care. A clustering of seven cases led to recognition of the outbreak and subsequent commencement of universal prophylaxis with oseltamivir 75 mg/day in all inpatients within the unit. Strict infection control processes were reinforced concurrently. There were no further cases of influenza A linked to the outbreak after the implementation of universal oseltamivir prophylaxis. Three later cases were linked to H1N1 exposure during the original outbreak. H1N1 influenza infection is associated with significant mortality in hematology patients. Universal prophylaxis with oseltamivir during a nosocomial outbreak appeared to be effective in controlling spread of the virus. We recommend early institution of infection control and universal prophylaxis in any nosocomial outbreak of influenza.

Nosocomial influenza: encouraging insights and future challenges.

The prevalence and incidence of viral nosocomial influenza infections in healthcare settings are underestimated. Nosocomial influenza outbreaks are frequent, and control remains challenging in acute care and long-term healthcare settings. This review examines recent publications on the determinants of nosocomial influenza prevention and control. Nosocomial influenza outbreaks occur in various healthcare settings, especially among the frail and elderly. The correct diagnosis is commonly missed because a substantial proportion of asymptomatic cases can transmit infections. Rapid diagnosis will facilitate rapid identification of cases and the implementation of control measures but needs confirmation in some circumstances, such as the description of transmission chains. Links between patients and healthcare personnel (HCP) have been well explored by phylogenetic virus characterization and need additional refinement and study. The preventive role of HCP vaccination in influenza incidence among patients should be investigated further in various settings to take into account different strategies for vaccination (i.e. voluntary or mandatory vaccination policies). Indeed, in Europe, influenza vaccination remains modest, whereas in North America hospitals and some states and provinces are now mandating influenza vaccination among HCP. The variability of vaccine effectiveness by seasonal epidemics is also an important consideration for control strategies. When influenza cases occur in the community, the risk of transmission and nosocomial cases increase in healthcare settings requiring vigilance among staff. Surveillance and early warning systems should be encouraged. Outbreak control needs appropriate identification of cases and transmission chains, and rapid implementation of control measures. Vaccination policies in conjunction with appropriate infection control measures could reduce virus spreading in hospitals. HCP vaccination coverage must be improved.

Genotyping Influenza Virus by Next-Generation Deep Sequencing in Clinical Specimens.

Rapid and accurate identification of an influenza outbreak is essential for patient care and treatment. We describe a next-generation sequencing (NGS)-based, unbiased deep sequencing method in clinical specimens to investigate an influenza outbreak. Nasopharyngeal swabs from patients were collected for molecular epidemiological analysis. Total RNA was sequenced by using the NGS technology as paired-end 250 bp reads. Total of 7 to 12 million reads were obtained. After mapping to the human reference genome, we analyzed the 3-4% of reads that originated from a non-human source. A BLAST search of the contigs reconstructed de novo revealed high sequence similarity with that of the pandemic H1N1 virus. In the phylogenetic analysis, the HA gene of our samples clustered closely with that of A/Senegal/VR785/2010(H1N1), A/Wisconsin/11/2013(H1N1), and A/Korea/01/2009(H1N1), and the NA gene of our samples clustered closely with A/Wisconsin/11/2013(H1N1). This study suggests that NGS-based unbiased sequencing can be effectively applied to investigate molecular characteristics of nosocomial influenza outbreak by using clinical specimens such as nasopharyngeal swabs.

Transmission and effect of multiple clusters of seasonal influenza in a Swiss geriatric hospital.

ObjectivesTo investigate a nosocomial outbreak of influenza.DesignProspective outbreak investigation with active case finding and molecular typing.SettingA large academic geriatric hospital in Switzerland.ParticipantsElderly hospitalized adults.MeasurementsBased on syndromic surveillance, a nosocomial influenza outbreak was suspected in February 2012. All suspected cases were screened for respiratory viruses using real‐time reverse transcription polymerase chain reaction of nasopharyngeal swabs. Infection control procedures (droplet precautions with single room isolation whenever possible) were implemented for all suspected or confirmed cases. Specimens positive for influenza viruses were processed and sequenced whenever possible to track transmission dynamics.ResultsRespiratory samples from 155 suspected cases were analyzed during the outbreak period, of which 69 (44%) were positive for influenza virus, 26 (17%) were positive for other respiratory viruses, and 60 (39%) were negative. Three other cases fulfilled clinical criteria for influenza infection but were not sampled, and one individual was admitted with an already positive test, resulting in a total of 73 influenza cases, of which 62 (85%) were classified as nosocomial. Five distinct clusters of nosocomial transmission were identified using viral sequencing, with epidemiologically unexpected in‐hospital transmission dynamics. Seven of 23 patients who experienced influenza complications died. Sixteen healthcare workers experienced an influenza‐like illness (overall vaccination rate, 36%).ConclusionNosocomial influenza transmission caused more secondary cases than repeated community importation during this polyclonal outbreak. Molecular tools revealed complex transmission dynamics. Low healthcare worker vaccination rates and gaps in recommended infection control procedures are likely to have contributed to nosocomial spread of influenza, which remains a potentially life‐threatening disease in elderly adults.

Leçons et perspectives concernant la prise en charge des grippes sévères depuis 2009

Depuis la pandémie grippale de 2009, la prise en charge des grippes sévères en réanimation a évolué : modalité de ventilation mécanique, utilisation des inhibiteurs de la neuramidase, recours précoces à l’assistance respiratoire extracorporelle. De nombreux états organisent des réseaux de surveillance épidémiologiques et un réseau de soins autour de centres référents et d’unités mobiles d’assistance. La lutte contre la grippe nosocomiale associe isolement et vaccination des personnels.

Vaccination of health care workers against influenza: Is it time to think about a mandatory policy in Europe?

Nosocomial influenza outbreaks and the transmission of influenza to health care workers (HCWs) have been well described. However, vaccine coverage among HCWs still remains low. After three decades of official recommendations that all HCWs be vaccinated against influenza, vaccination rates generally remain below 30% in Europe.Experiences in the USA have shown that mandatory policies achieve a compliance rate of nearly 100%. However, the discussion about mandatory vaccination policies for HCWs has not advanced very far in Europe. This article therefore discusses the question whether it is time to consider mandatory vaccination policies for HCWs in Europe. We further elaborate under which conditions mandatory vaccination polices would be ethically justified and how far these conditions are met in the case of influenza vaccination of HCWs.From a methodological perspective, it would be desirable to have further high-quality RCTs with a lower risk of bias that investigate the effectiveness of HCWs influenza vaccination. From a policy perspective, however, we have to decide whether we have already sufficient (albeit not perfect) evidence to justify mandatory influenza vaccination programs for HCWs.We conclude: Given the available evidence concerning the benefits, burdens and risks of HCWs influenza vaccination and the limited effectiveness of voluntary policies, it is time to consider mandatory vaccination policies for HCWs in Europe.

State law and influenza vaccination of health care personnel

Nosocomial influenza outbreaks, attributed to the unvaccinated health care workforce, have contributed to patient complications or death, worker illness and absenteeism, and increased economic costs to the health care system. Since 1981, the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (CDC) has recommended that all HCP receive an annual influenza vaccination.Health care employers (HCE) have adopted various strategies to encourage health care personnel (HCP) to voluntarily receive influenza vaccination, including: sponsoring educational and promotional campaigns, increasing access to seasonal influenza vaccine, permitting the use of declination statements, and combining multiple approaches. However, these measures failed to significantly increase uptake among HCP. As a result, beginning in 2004, health care facilities and local health departments began to require certain HCP to receive influenza vaccination as a condition of employment and annually. Today, hundreds of facilities throughout the country have developed and implemented similar policies. Mandatory vaccination programs have been endorsed by professional and non-profit organizations, state health departments, and public health. These programs have been more effective at increasing coverage rates than any voluntary strategy, with some health systems reporting coverage rates up to 99.3%.Several states have enacted laws requiring HCEs to implement vaccination programs for the workforce. These laws present an example of how states will respond to threats to the public's health and constrain personal choice in order to protect vulnerable populations.This study analyzes laws in twenty states that address influenza vaccination requirements for HCP who practice in acute or long-term care facilities in the United States. The laws vary in the extent to which they incorporate the six elements of a mandatory HCP influenza vaccination program. Four of the twenty states have adopted a broad definition of HCP or HCE. While 16/20 of the laws require employers to “provide,” “arrange for,” “ensure,” “require” or “offer” influenza vaccinations to HCP, only four states explicitly require HCEs to cover the cost of vaccination. Fifteen of the twenty laws allow HCP to decline the vaccination due to medical contraindication, religious or philosophical beliefs, or by signing a declination statement. Finally, three states address how to sanction noncompliant HCPs. The analysis also discusses the development of a model legal policy that legislators could use as they draft and revise influenza prevention guidelines in health care settings.

Impact of the Ottawa Influenza Decision Aid on healthcare personnel's influenza immunization decision: a randomized trial

Influenza immunization for healthcare personnel reduces frequency and severity of nosocomial influenza outbreaks and influenza-associated morbidity and mortality among patients. The Ottawa Influenza Decision Aid (OIDA) was developed to assist undecided healthcare workers in deciding whether or not to be immunized. To assess the impact of the OIDA, and to ascertain whether its use would increase the level of confidence in healthcare workers' influenza immunization decision and positively affect their intent to be immunized. Single-centre, single-blind, parallel-group, randomized controlled trial. Eight per cent (151 of 1886) of the unimmunized healthcare personnel were randomized. Of 107 eligible respondents, 48 were in the Ottawa Influenza Decision Aid (OIDA) group and 59 in the control group. A statistically significant (P = 0.020) greater improvement in confidence in immunization decision was observed in the OIDA group compared with the control group. Whereas the odds of changing intent to be immunized from 'no/unsure' to 'yes' was 2.4 times greater in the OIDA group, this result did not reach statistical significance after adjusting for intent to be immunized at baseline. The post-OIDA intent to be immunized in the OIDA and control groups compared to the pre-OIDA intent to be immunized showed that the OIDA had a significant effect on reducing uncertainty (P = 0.035). Using an accessible, balanced, understandable format for all healthcare personnel about their influenza immunization decision appears to have an impact on both healthcare personnel's confidence in their immunization decision and in their intent to be immunized.

Sequence-based identification and characterization of nosocomial influenza A(H1N1)pdm09 virus infections

Highly transmissible viruses such as influenza are a potential source of nosocomial infections and thereby cause increased patient morbidity and mortality. To assess whether influenza virus sequence data can be used to link nosocomial influenza transmission between individuals. Dutch A(H1N1)pdm09-positive specimens from one hospital (N = 107) were compared with samples from community cases (N = 685). Gene fragments of haemagglutinin, neuraminidase and PB2 were sequenced and subsequently clustered to detect patients infected with identical influenza viruses. The probability of detecting a second patient was calculated for each hospital cluster against the background diversity observed in hospital and community strains. All clusters were further analysed for possible links between patients. Seventeen A(H1N1)pdm09 hospital clusters were detected of which eight had a low probability of occurrence compared with background diversity (P < 0.01). Epidemiological analysis confirmed a total of eight nosocomial infections in four of these eight clusters, and a mother-child combination in a fifth cluster. The nine clusters with a high probability of occurrence involved community cases of influenza without a known epidemiological link. If a background sequence dataset is available, the detection of hospital sequence clusters that differ from dominant community strains can be used to select clusters requiring further investigation by hospital hygienists before a nosocomial influenza outbreak is epidemiologically suspected.

Genotyping of a nosocomial outbreak of pandemic influenza A/H1N1 2009

Background Epidemiological surveys have revealed outbreaks of pandemic influenza A (H1N1) 2009 in several different contexts. Molecular characterization of the influenza virus could help to provide a more accurate description of these outbreaks. Objective To genotype pandemic influenza A (H1N1) 2009 isolates from an epidemiologically defined nosocomial outbreak. Study design We sequenced the neuraminidase (NA) and hemagglutinin (HA) influenza A (H1N1) 2009 genes from ten HIV-positive patients involved in an epidemiologically defined outbreak in the Clinical Microbiology and Infectious Diseases (CMID) Department. Sequences were aligned to search for specific genetic features of the involved strain. We also analyzed 37 unrelated influenza A (H1N1) 2009 cases from other hospital departments. All the sequences were used to obtain phylogenetic trees. Results Identical genotypic features were shared by nine of the 10 cases initially considered to be involved in the outbreak, but not by the remaining case. These features involved two silent mutations at N385 and V407 in the NA gene and three amino acid substitutions in the HA gene (D225E, A189T, and P300S). Searching for these substitutions in patients with influenza A (H1N1) 2009 hospitalized in other departments during the same period allowed us to identify an additional unsuspected immunocompetent case. The five outbreak-specific substitutions were absent in the remaining 36 unrelated controls. One of the substitutions (P300S) rendered detection of this variant by the CDC protocol inefficient. The other outbreak-specific substitutions (D225E and A189T) were identified at codons that have been analyzed in the context of virulence. Conclusions Genotyping is essential to ensure a more accurate description of pandemic influenza A (H1N1) 2009 outbreaks.

New interventions to increase influenza vaccination rates in health care workers

The most effective strategy for avoiding nosocomial influenza outbreaks is through vaccination of health care workers (HCWs). In Spain, HCW vaccination coverage rarely exceeds 25%. The objective of this study was to determine whether an active vaccination campaign promoting communication among HCWs increased influenza vaccination coverage rates and permitted a shorter campaign. This was a before-after trial, comparing free mobile vaccination teams without and with strategies promoting HCW involvement by means of weekly educational and promotional messages through electronic mail, including 2 prize draws for vaccinated HCWs and a Web page including pictures of vaccinated HCWs and all senior hospital management. Weekly coverages were publicized, the staff of mobile units was increased, and their routes in the hospital were advertised. The study population was >4500 HCWs (permanent and temporary staff) at a Spanish university hospital during the 2007-08 and 2008-09 influenza seasons. Coverage was 23% (95% confidence interval [CI], 22.5%-24.9%) in the 2007-08 season and 37% (95% CI, 34.7%-37.4%) in 2008-09 season. The vaccination rate was highest in HCWs aged > or =65 years and in physicians. The weekly vaccination rates were significantly higher for the 2008-09 season compared with the 2007-08 season except for the first and third weeks; for example, in week 2, the rate was 1.7 HCWs per 100 persons-week (95% CI, 1.3-2.1) in 2007-08, compared with 3.7 HCWs per 100 persons-week (95% CI, 3.2-4.4) in 2009-09. Rate increases were concentrated in the first weeks of the program, with a peak occurring in week 3 during the 2007-08 season and in week 2 during the 2008-09 season. This intervention improved influenza vaccination coverage of HCWs and allowed more rapid achievement of higher coverage.

Influenza vaccine coverage for healthcare workers in geriatric settings in France

Because of a relative lack of efficiency of influenza vaccine in the elderly population, influenza outbreaks in geriatric healthcare settings are probable, despite high influenza vaccination rates in patients. Nosocomial influenza outbreaks, more probably related to healthcare workers, have also been reported. Therefore, vaccination of healthcare workers is considered to be an important preventive policy, to decrease the in-hospital influenza burden during the viral circulation period. This multicenter study measured influenza vaccine coverage of Health Care Worker in 102 geriatric healthcare settings (acute care, rehabilitation care, long-term care) by a first questionnaire. A second questionnaire assessed main factors associated with vaccine acceptance. 102 geriatric healthcare settings (20%) answered the first questionnaire. Vaccine coverage for physicians (n=187), nurses (n=631) and nurse assistants (n=1487) were 48.4%, 30.5% and 27.9%, respectively. Vaccination rates were correlated between occupational categories according to healthcare settings. Vaccination rates were significantly lower in acute care settings compared with rehabilitation and long-term care settings. Local recommendations was reported for 29.9%, but was not correlated with vaccine coverage. The second questionnaire showed that lack of motivation and knowledge, and organizational problems were the three main reasons for reluctance to be vaccinated. In French geriatric settings, influenza vaccine coverage of healthcare workers is low and highly variable, according to the type of healthcare setting. A group effect was found between occupational categories. However, the reasons for non-acceptance need further evaluation to improve HCW influenza vaccine coverage.

Épidémie de grippe nosocomiale dans un service de gériatrie: Efficacité des mesures de prévention

To describe a nosocomial influenza outbreak and the pharmacologic and nonpharmacologic control measures implemented in a hospital ward with beds for acute geriatric care and rehabilitation care.Descriptive survey conducted in the geriatrics department of a university hospital. An influenza outbreak occurred in February 2005 in 2 of the department's 3 separate units. The study concerned all patients in the 2 affected units (A and B) present during the outbreak, as well as all department staff. Once cases of influenza were confirmed, elderly patients in contact with influenza patients received chemoprophylaxis with oseltamivir when it became available.Thirty-eight (76%) patients and 62 (38%) staff members had been vaccinated. The time from the initial symptoms of the first case until implementation of control measures was 7 days in unit A but only 1 day in unit B, -and chemoprophylaxis of contact patients began in 9 days and 24 hours respectively. The attack rate was 38% in the 38 vaccinated patients and 29% in the 14 unvaccinated patients (NS). All cases met the definition of nosocomial infection. No deaths imputable to influenza occurred during the outbreak. The implementation of the nonpharmacologic measures aimed at preventing spread of the outbreak presented no particular difficulty, except for compliance with geographic isolation of some patients with dementia and influenza. The difference between the attack rates for the two sectors (48% for unit A and 28% for unit B) suggests that the preventive measures were effective. Tolerance to chemoprophylaxis with oseltamivir was good.This study confirmed that influenza can affect elderly hospital patients, even those in whom the vaccination rate is high, and that rapid detection of the outbreak and immediate implementation of pharmacologic and nonpharmacologic preventive measures can limit its spread.

Influenza: Lessons Learned from an Outbreak, Post-Exposure Prophylaxis and Vaccination Campaigns

ISSUE: Influenza is a serious nosocomial pathogen in high risk patient populations and causes an average of 36,000 deaths per year in the United States. Those at greatest risk of serious complications are persons aged less than 2 and greater than 65, and those with chronic medical conditions. Nosocomial acquisition of influenza should be minimized by effective vaccination, surveillance, and aggressive outbreak abatement. PROJECT: In 2003, a nosocomial outbreak of influenza was detected in the pediatric ICU. Control measures included vaccination of staff, patients and visitors, visitor curtailment and post exposure chemoprophylaxis. A survey of 142 healthcare workers (HCWs) receiving post-exposure chemoprophylaxis revealed that amongst the 69 (49%) respondents, amantadine was poorly tolerated and adherence was poor (41%). The most frequent side effects consisted of insomnia, nausea, diarrhea and dizziness. In response to this outbreak, a comprehensive re-evaluation of the influenza prevention program was conducted. A housewide questionnaire determined barriers to vaccination. An online survey targeted approximately 4500 employees resulting in 1939 completed surveys (response rate of 43%). Of those responding, 542 (28%) indicated they did not receive the influenza vaccine. Of those electing not to receive the vaccine, 153 (28%) indicated that the vaccine was not efficacious, 146 (27%) responded that the vaccine was associated with systemic toxicity, and 125 (23%) responded they were not at risk for influenza infection. Data obtained from the survey was utilized to develop educational material and to address these and other identified issues. RESULTS: Subsequent vaccination campaigns increased the overall rate of vaccination in high risk areas from 78% to 88% (p LESSONS LEARNED: 1) Effective influenza vaccination programs require yearly re-evaluation and strategies for improvement. Vaccination rates of 90% or greater are possible. Convenient vaccine delivery with local unit champions appears important in boosting vaccination rates. 2) Amantidine is poorly tolerated by HCWs, resulting in sub-optimal chemoprophylaxis and alternative (neuramindase inhibitor) chemoprophylaxis should be considered.