Nosocomial Influenza Infection Research Articles

434 - The Impact of Nosocomial Influenza Infection on Hospitalization Outcomes in Patients Undergoing Allogenic Hematopoietic Stem Cell Transplant: A National Inpatient Database Analysis (2002–2019)

434 - The Impact of Nosocomial Influenza Infection on Hospitalization Outcomes in Patients Undergoing Allogenic Hematopoietic Stem Cell Transplant: A National Inpatient Database Analysis (2002–2019)

A strict mask policy for hospital staff effectively prevents nosocomial influenza infections and mortality: monocentric data from five consecutive influenza seasons

Influenza infections acquired in hospital show increased mortality, especially in elderly patients with risk factors. Nevertheless, vaccination rates are low among both high-risk patients and healthcare workers (HCWs). To more effectively prevent influenza infections in the hospital during the influenza season, a strict mouth-nose protection (MNP) requirement was introduced for all staff throughout the shift on the affected wards as an intervention and its effect on nosocomial infection rates was studied. The present data were obtained in a retrospective, monocentric analysis over a period of four consecutive influenza seasons from 2015 to 2019. MNP for all staff during the whole shift as an intervention was introduced in 2017 and for the following seasons if at least three influenza patients were in the ward at the same time. Data from hospitalized influenza patients before and after intervention were compared with regard to nosocomial incidences and mortality. In the years with strict mandatory MNP (2017-2019), the nosocomial influenza incidence fell nearly 50% (odds ratio: 0.40; 95% confidence interval: 0.28-0.56; P < 0.001) accompanied by a significant reduction in nosocomial mortality by 85% (0.15; 0.02-0.70; P= 0.007). The infectious pressure indicated by influenza incidences and patient-days at risk were comparable before and after intervention, as was the low rate of vaccine uptake by nurses. Mandatory MNP for HCWs effectively protects patients from nosocomial influenza infections and mortality.

Influenza Vaccination Strategies in Healthcare Workers: A Cohort Study (2018-2021) in an Italian University Hospital.

Vaccinating healthcare workers (HCWs) is the most effective intervention for preventing nosocomial influenza infection. However, influenza vaccination coverage (VC%) among HCWs remains low. The aim of the study was to analyse the trend of VC% among healthcare workers in an Italian hospital through a three-year vaccination project covering three influenza seasons (2018–2019, 2019–2020, and 2020–2021). A gap analysis was performed at the case base (2018–2019), on-site vaccination was trialled in the 2019–2020 season, and an integrated vaccination offer (on-site vaccination and the classic offer at a vaccination clinic) was implemented for the 2020–2021 season. For each unit of vaccinated HCWs, the following variables were recorded: main demographic details, area of affiliation (medical/surgical/services), and professional category. Logistic regression analyses were performed to assess the relationship between outcome (undergoing vaccination in 2020–2021) and other variables related to the healthcare workers’ characteristics. In the three seasons, VC% values of 13.2%. 27.7%, and 58.9% were recorded, respectively (p < 0.005). The highest VC% was recorded among physicians (94.93%), in the medical area (63.27%), and males (62.59%) and in general among the youngest HCWs. Comparison of the coverage values recorded in the three seasons showed that in the last season considered (2020–2021) about 80% of health workers preferred to be vaccinated in the workplace instead of using the standard vaccination delivery method (invitation to attend the vaccination clinic). Our study suggests that the integrated vaccination offer may lead to an increase in VC% among HCWs compared to the classical offer modalities.

Nosocomial influenza in south-western Swiss hospitals during two seasonal epidemics: an observational study

In Switzerland each year, influenza leads to between 112,000 and 275,000 medical consultations. Data on nosocomial influenza infection are limited. To describe nosocomial cases of seasonal influenza in south-western Switzerland. This study was conducted during two seasonal influenza epidemics from 2016 to 2018 in 27 acute care public hospitals in south-western Switzerland. During these two time-periods, every patient hospitalized for >72 h who was positively screened by reverse transcription-polymerase chain reaction or antigen detection for influenza was included in the survey. Characteristics of patients included age, sex, and comorbidities. Included patients were followed up until discharge or death. Complications and administration of antineuraminidases and/or antibiotics were registered. The median influenza vaccine coverage of healthcare workers was 40%. In all, 836 patients were included (98% with type A influenza virus in 2016-2017; 77% with type B virus in 2017-2018). Most patients (81%) had an unknown vaccine status. Overall, the incidence of nosocomial influenza was 0.5 per 100 admissions (0.35 per 1000 patient-days). The most frequent comorbidities were diabetes (20%), chronic respiratory diseases (19%), and malnutrition (17%). Fever (77%) and cough (66%) were the most frequent symptoms. Seventy-one percent of patients received antineuraminidases, 28% received antibiotics. Infectious complications such as pneumonia were reported in 9%. Overall, the all-cause mortality was 6%. The occurrence of nosocomial influenza underlines the importance of vaccinating patients and healthcare workers, rapidly recognizing community- or hospital-acquired cases, and applying adequate additional measures to prevent dissemination, including the timely administration of antineuraminidases to avoid antibiotic use (and misuse).

Influenza surveillance: Findings from a tertiary care adult hospital in Singapore, Jan 2010–Sept 2019

Background: Influenza virus infection is known to cause excessive hospitalisations and deaths in the elderly during seasonal peaks and pandemics. Methods and materials: We conducted a retrospective, observational cohort study on patients admitted to Tan Tock Seng Hospital from 1 Jan 2010 to 30 Sept 2019. Results: During the study period, 11,728 patients were identified with laboratory-confirmed influenza, influenza A 8,783 (75%) and influenza B 2,945 (25%) respectively. Majority of influenza cases were elderly (68% aged >65 y) with 51% of female, and 8,872 (76%) patients had Charlson co-morbidity score <3. 483 (4%) nosocomial influenza cases (patients had laboratory confirmation >3 d after admission) were identified. Influenza A/B ratio was significantly different between nosocomial and non-nosocomial cases (p = 0.002). Individuals with nosocomial influenza (median 74; range 21–102 y) were older than non-nosocomial cases (median 72; range 13–110 y) (p < 0.001). 49 deaths (10%) occurred among patients with nosocomial influenza infections. During the study period, 754 severely ill patients (who required intensive care and/or died) were identified with overall 6.4% (p = 0.017) among all influenza admissions; 2010 (55, 7.0%), 2011 (49, 6.2%), 2012 (74, 6.5%), 2013 (76, 7.3%), 2014 (84, 6.3%), 2015 (114, 8.4%), 2016 (79, 5.6%), 2017 (115, 6.6%), 2018 (79, 5.7%) and 2019 (29, 4.0%) respectively. On multivariate analysis, factors independently associated with nosocomial influenza cases were co-morbidities of congestive heart failure (AOR 1.47, 95%CI 1.16–1.86), renal disease (AOR 1.76, 95%CI 1.38–2.23), cerebrovascular disease (AOR 1.79, 95%CI 1.36–2.35), any malignancy (AOR 2.19, 95%CI 1.63–2.94) and influenza A (AOR 1.44, 95% 1.14–1.82). In contrast, chronic pulmonary disease (AOR 0.59, 95%CI 0.46–0.76) was less common in nosocomial influenza cases after adjusting for age, gender, ethnicity and admission year. On multivariable analysis, predictors of in-hospital 30 d mortality were age (AOR 1.04, 95%CI 1.03–1.05), Charlson score (AOR 1.18, 95%CI 1.13–1.24) and hospital-acquired influenza (AOR 1.57, 95%CI 1.04–2.37) after adjusting for gender, ethnicity, influenza subtypes and admission year. Conclusion: Annual influenza vaccination should be actively promoted not only for patients with chronic medical conditions but also for healthcare workers who nurse patients especially with low immunity.

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 &gt;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

Absence of nosocomial influenza and respiratory syncytial virus infection in the coronavirus disease 2019 (COVID-19) era: Implication of universal masking in hospitals.

Universal masking for healthcare workers and patients in hospitals was adopted to combat coronavirus disease 2019 (COVID-19), with compliance rates of 100% and 75.9%, respectively. Zero rates of nosocomial influenza A, influenza B, and respiratory syncytial virus infection were achieved from February to April 2020, which was significantly lower than the corresponding months in 2017-2019.

Hospital-acquired influenza infections detected by a surveillance system over six seasons, from 2010/2011 to 2015/2016

BackgroundIn addition to outbreaks of nosocomial influenza, sporadic nosocomial influenza infections also occur but are generally not reported in the literature.This study aimed to determine the epidemiologic characteristics of cases of nosocomial influenza compared with the remaining severe cases of severe influenza in acute hospitals in Catalonia (Spain) which were identified by surveillance.MethodsAn observational case-case epidemiological study was carried out in patients aged ≥18 years from Catalan 12 hospitals between 2010 and 2016. For each laboratory-confirmed influenza case (nosocomial or not) we collected demographic, virological and clinical characteristics. We defined patients with nosocomial influenza as those admitted to a hospital for a reason other than acute respiratory infection in whom ILI symptoms developed ≥48 h after admission and influenza virus infection was confirmed using RT-PCR. Mixed-effects regression was used to estimate the crude and adjusted OR.ResultsOne thousand seven hundred twenty-two hospitalized patients with severe laboratory-confirmed influenza virus infection were included: 96 (5.6%) were classified as nosocomial influenza and more frequently had > 14 days of hospital stay (42.7% vs. 27.7%, P < .001) and higher mortality (18.8% vs. 12.6%, P < .02). The variables associated with nosocomial influenza cases in acute-care hospital settings were chronic renal disease (aOR 2.44 95% CI 1.44–4.15) and immunodeficiency (aOR 1.79 95% CI 1.04–3.06).ConclusionsNosocomial infections are a recurring problem associated with high rates of chronic diseases and death. These findings underline the need for adherence to infection control guidelines.

Risk factors and clinical characteristics of patients with nosocomial influenza A infection.

Influenza is a public health burden, responsible for more than half a million deaths worldwide each year and explosive outbreaks in-hospital care units. At present, little is known about clinical characteristics and outcomes with nosocomial influenza infection. To assess clinical characteristics and outcome between nosocomial and community-acquired (CA) influenza in a tertiary care hospital. A retrospective study of hospitalized patients in a French tertiary care hospital from 1stDecember 2016 to 28thFebruary 2017 for flu-illness confirmed by reverse transcription PCR. Overall, 208 patients with laboratory-confirmed influenza were included; whose 49 nosocomial cases (23.6%). Patients with nosocomial influenza were significantly older (79.1 ± 15.5 vs 64.8 ± 31.1 years old; P = .003), with the more rapidly fatal disease (10.2% vs 1.3%; P = .0032). They had a less respiratory failure (8.2% vs 21.4%; P = .036) but had a longer length of hospitalization (47.3 vs 12.9 days; P < .001) than patients with CA influenza. During this influenza outbreak, 19 patients died (9.1%), none of them were vaccinated. Effective control of outbreaks in hospital facilities is challenging. Hospitalized patients are vulnerable to nosocomial Influenza infections that can increase the length of stay and be responsible forthe death. Surveillance and early warning systems should be encouraged. Vaccination policies in conjunction with isolation measures and better hand hygiene could reduce virus spreading in hospitals.

Presenteeism among health care workers with laboratory-confirmed influenza infection: A retrospective cohort study in Queensland, Australia

A high prevalence of working while ill (presenteeism) has been documented among health care workers (HCWs). However, previous evidence is primarily based on nonspecific causes of sickness and self-reported data. Our study examined presenteeism among HCWs with laboratory-confirmed influenza. The data pertaining to laboratory-confirmed influenza cases and history of sick leave among HCWs in Queensland, Australia, were collected from 2009-2015. The incidence and duration of sick leave around the time of disease confirmation were analyzed. The associations of factors, such as job category and employment status, on presenteeism were assessed with regression analyses. The overall sick leave incidence was 85.9% in the laboratory-confirmed periods, which translates that 14.1% of HCWs were working while ill with influenza. Among medical doctors, approximately one-quarter of them were attending work in the period. A shorter duration of leave was also observed among medical doctors and full-time employees compared with other HCWs and part-time employees. Presenteeism among HCWs with influenza put both HCWs and patients at risk by increasing potential for transmission. Our findings emphasize the importance of an integrated approach including both HCW sick leave management and vaccination for strategic prevention and control of nosocomial influenza infection.

Effects of guided flow in reducing nosocomial influenza infection in hospital

Objective To investigate the effect of guided flow in reducing nosocomial influenza infection. Methods By convenience sampling, from October 2017 to March 2018, a total of 266 patients with flu-like symptoms aged 60 years or more who attended in the Department of Outpatient and Emergency, Health Care Sector, Peking Union Medical College Hospital were selected. The patients were numbered according to the time of admission, and divided into the control group (n=120) who were admitted from October to December of 2017 and the observation group (n=146) who were admitted from January to March of 2018. Routine flu nursing flow was adopted for the control group, while guided nursing flow was adopted for the observation group. The general profile of the patients was recorded, and the two groups were compared in terms of the infection rate in medical staff and satisfaction degree towards the quality of nursing care. Results The rate of infection and satisfaction degree towards the quality of nursing care was 30.43% and 74.17% in the control group and 4.35% and 89.73% in the observation group respectively. After the adoption of the guided flow nursing procedure, the rate of infection in medical staff reduced and the satisfaction degree towards the quality of nursing care increased with statistical difference (P<0.05) . Conclusions The implementation of guided flow intervention can timely isolate and diagnose influenza virus, reduce the probability of cross-infection, prescribe symptomatic medication, reduce the complications of elderly influenza patients, and the regular follow-up visit can improve patients' satisfaction towards the quality of nursing care. Key words: Influenza, human; Guided flow; Nosocomial infection; Infection rate of medical staff; Satisfaction degree towards nursing care

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.

Association of increased influenza vaccination in health care workers with a reduction in nosocomial influenza infections in cancer patients

Vaccination of health care workers (HCWs) remains a key strategy to reduce the burden of influenza infections in cancer patients. In this 8-year study, we evaluated the effect of a multifaceted approach, including a mandatory influenza vaccination program, on HCW vaccination rates and its effect on nosocomial influenza infections in cancer patients. The influenza vaccination rate of all employees significantly increased from 56% (8,762/15,693) in 2006-2007 to 94% (17,927/19,114) in 2013-2014 (P < .0001). The 2009 mandatory participation program increased HCW vaccination rates in the targeted groups (P < .0001), and the addition of an institutional policy in 2012 requiring influenza vaccination or surgical mask use with each patient contact further increased vaccination rates by 10%-18% for all groups in 1 year. The proportion of nosocomial influenza infections significantly decreased (P = .045) during the study period and was significantly associated with increased HCW vaccination rates in the nursing staff (P = .043) and in personnel working in high-risk areas (P = .0497). Multifaceted influenza vaccination programs supported by institutional policy effectively increased HCW vaccination rates. Increased HCW vaccination rates were associated with a reduction in the proportion of nosocomial influenza infections in immunocompromised cancer patients.

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.

A review of the winter influenza strategy for hospitals within a major district health board in New Zealand following the 2012 Influenza season

Abstract Winter influenza planning is an integral part of a health services preparation for the annual increase in respiratory virus infections and associated hospital admissions in New Zealand. A moderate to severe influenza A (H3N2) outbreak occurred in the winter of 2012 resulting in an unprecedented number of attendances of patients with influenza-like illness at the Canterbury District Health Board (CDHB) hospital’s emergency assessment areas. A review of the hospital winter influenza strategy following this outbreak, included the use of dedicated influenza wards, extensive diagnostic testing of patients, infection control advice, staff influenza vaccination and the use of Oseltamivir for treatment of patients and prophylaxis of their contacts. The review found that 534 patients were seen and laboratory confirmed to have influenza, 347 patients were admitted and 40 nosocomial influenza infections recorded over an 11 weeks period. The strategy contributed to the management of the hospital admission of patients with influenza, a relatively low number of nosocomial influenza infections in the dedicated admission wards and low in-hospital mortality. The use of diagnostic testing for influenza with planned escalation of services supported the clinical decision to treat patients with confirmed influenza and prophylaxis contacts with Oseltamivir probably facilitated appropriate discharge of patients.

Oseltamivir Treatment for Influenza in Hospitalized Children Without Underlying Diseases

To determine whether the treatment with oseltamivir improves the outcome of children with confirmed influenza infection and no other underlying disease. Multicentric, retrospective study performed in 10 hospitals of Madrid between September 2010 and June 2012. All children admitted to the hospitals with confirmed influenza infections were eligible. Children with risk factors for serious disease and nosocomial influenza infections were excluded. Asthma was not considered an exclusion factor. The study compared patients treated and untreated with oseltamivir. Fever duration, oxygen support, antibiotics administration, length of hospital stay, intensive care admission and bacterial complications were analyzed. To compare variables, χ(2) test, Fisher exact test, ANOVA or Mann-Whitney U test were used. Two hundred eighty-seven children were included and 93 of them were treated with oseltamivir (32%). There were no significant differences between treated and untreated patients in days of fever after admission (1.7 ± 2; 2.1 ± 2.9, P > 0.05), length of stay (5.2 ± 3.6; 5.5 ± 3.4, P > 0.05), days of hypoxia (1.6 ± 2.3; 2.1 ± 2.9, P > 0.05), diagnosis of bacterial pneumonia (10%; 17%, P > 0.05), intensive care admission (6.5%; 1.5%,P > 0.05) or antibiotic prescription (44%; 51%, P > 0.05). There were no differences when the population was stratified by age (below or over 1 year) or by the presence or absence of asthma. There were no proven benefits of treatment with oseltamivir in hospitalized pediatric patients without the underlying diseases or risk factors for developing a serious illness, including those with asthma.

Protecting patients, protecting healthcare workers: a review of the role of influenza vaccination.

MUSIC T. (2012) A review of the role the role of influenza vaccination in protecting patients, protecting healthcare workers the role of influenza vaccination. International Nursing Review59, 161–167Aim:Many health authorities recommend routine influenza vaccination for healthcare workers (HCWs), and during the 2009 A (H1N1) pandemic, the World Health Organization (WHO) recommended immunization of all HCWs worldwide. As this remains an important area of policy debate, this paper examines the case for vaccination, the role of local guidelines, barriers to immunization and initiatives to increase uptake.Background:Seasonal influenza is a major threat to public health, causing up to 1 million deaths annually. Extensive evidence supports the vaccination of priority groups, including HCWs. Immunization protects HCWs themselves, and their vulnerable patients from nosocomial influenza infections. In addition, influenza can disrupt health services and impact healthcare organizations financially. Immunization can reduce staff absences, offer cost savings and provide economic benefits.Methods:This paper reviews official immunization recommendations and HCW vaccination studies, including a recent International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) survey of 26 countries from each region of the world.Results:HCW immunization is widely recommended and supported by the WHO. In the IFPMA study, 88% of countries recommended HCW vaccination, and 61% supported this financially (with no correlation to country development status). Overall, coverage can be improved, and research shows that uptake may be impacted by lack of conveniently available vaccines and misconceptions regarding vaccine safety/efficacy and influenza risk.Conclusions:Many countries recommend HCW vaccination against influenza. In recent years, there has been an increased uptake rate among HCWs in some countries, but not in others. Several initiatives can increase coverage, including education, easy access to free vaccines and the use of formal declination forms. The case for HCW vaccination is clear, and in an effort to further accelerate uptake as a patient safety measure, an increasing number of healthcare organizations, particularly in the USA, are implementing mandatory immunization policies, similar to other obligatory hygiene measures. However, it would be desirable if similar high vaccination uptake rates could be achieved through voluntary procedures.

Are medical residents a “core group” for future improvement of influenza vaccination coverage in health-care workers? A study among medical residents at the University Hospital of Palermo (Sicily)

Despite international recommendations, vaccination coverage among European healthcare workers, including physicians, is widely recognized as unsatisfactory. In order to plan tailored vaccination campaigns and increase future coverage, we investigated reasons for refusing vaccination and determinants associated with influenza vaccine uptake among young health care workers. A survey was carried out during September and October 2010 on medical residents attending post-graduate Schools of the Medical Faculty at the University of Palermo (Italy). Each participant completed an anonymous web-based questionnaire including items on demographic and occupational characteristics, knowledge, attitudes and behaviours with regard to influenza and influenza vaccination, and main sources of information. A total of 202 (66.9%) out of 302 medical residents participated in the survey. During the 2009-2010 influenza vaccine campaign, 44 residents (21.8%) were vaccinated against seasonal influenza and 84 (41.6%) against pandemic influenza A (H1N1) 2009. For the impending 2010-2011 influenza season, 45 (22.3%) stated their intention to get vaccinated against seasonal influenza, 40 (19.8%) were uncertain and 117 (57.9%) were opposed. Considering themselves to be a high risk group for developing influenza was significantly associated with vaccination against both 2009-2010 seasonal (adj-OR=1.46; 95% CI=1.05-2.04) and pandemic A (H1N1) influenza (adj-OR 1.38; 95% CI=1.08-1.75). Intention to get vaccinated against 2010-2011 seasonal influenza was significantly more frequent in participants who had a high perception of efficacy/safety (adj-OR=1.49; 95% CI=1.05-2.12). After adjusting for confounding, vaccinations against seasonal 2009-2010 influenza, pandemic influenza A (H1N1) 2009 and seasonal 2010-2011 influenza were significantly more frequent in residents who were vaccinated against influenza at least once in the previous five influenza seasons. Influenza vaccination among medical residents appears to be habitual, with little comprehension of the rationale and logic for vaccination, including the need to be vaccinated to protect patients from nosocomial influenza infection. Our study suggests the importance of prioritizing residents for vaccination campaigns, as they represent "the future" and include a core group that habitually accepts vaccination.

Molecular Characteristics of Outbreaks of Nosocomial Infection with Influenza A/H3N2 Virus Variants

To describe outbreaks of nosocomial influenza infection with molecular methods and to elucidate the viral linkages among outbreak case patients including both inpatients and healthcare workers (HCWs). A 180-bed acute and long-term care hospital in Japan. Retrospective observational study of nosocomial outbreaks of infection with influenza A/H3N2. Together with information about onset dates and vaccination history, we obtained nasopharyngeal swab samples from individuals with cases of influenza or influenza-like illness (ILI). The hemagglutinin genes of the recovered viruses were sequenced and compared, along with those of community-circulating strains, for similarity by phylogenetic tree analysis. The outbreaks occurred from February 26 through April 3, 2007, during the 2006-2007 epidemic season, and they involved 11 patients and 13 HCWs. The 2 outbreaks involved 2 different genotypes of influenza A/H3N2 viruses. These virus variants were closely related to the influenza strains that were circulating in the community during the same epidemic season. This study showed the dissemination of highly homologous influenza virus variants among inpatients and HCWs within a short period, as a result of nosocomial transmission. These strains were also similar to influenza strains that were circulating in the community.

The use of personal protective equipment for control of influenza among critical care clinicians: A survey study

Intensive care units (ICUs) are potential high-risk areas for transmission of viruses causing febrile respiratory illness, such as influenza. Healthcare-associated influenza is prevented through healthcare worker (HCW) vaccination and effective use of U.S. Centers for Disease Control and Prevention recommended infection control practices, including use of personal protective equipment (PPE). Although effective PPE use may significantly reduce healthcare-associated influenza transmission, PPE adherence among ICU HCWs for preventing nosocomial influenza infection has not been evaluated. To characterize ICU HCW behavior, knowledge, and attitudes about recommended precautions for the prevention of healthcare-associated influenza infections. A survey of 292 internal medicine housestaff, pulmonary/critical care fellows and faculty, nurses, and respiratory care professionals working in four ICUs in two hospitals in Baltimore, MD. Of those surveyed, 88% (n = 256) completed the survey. Only 63% of respondents were able to correctly identify adequate influenza PPE, and 62% reported high adherence (>80%) with PPE use for prevention of nosocomial influenza. In multivariable modeling, odds of high adherence varied by clinician type. Respondents who believed adherence was inconvenient had lower odds of high adherence (odds ratio 0.42, 95% confidence interval 0.22-0.82), and those reporting likelihood of being reprimanded for nonadherence were more likely to adhere (odds ratio 2.40, 95% confidence interval 1.25-4.62). ICU HCWs report suboptimal levels of influenza PPE adherence. This finding in a high-risk setting is particularly concerning, given that it likely overestimates actual behavior. Both suboptimal adherence levels and significant PPE knowledge gaps indicate that ICU HCWs may be at a substantial risk of developing and/or transmitting nosocomial respiratory viral infection. Improving respiratory virus infection control will likely require closing knowledge gaps and changing organizational factors that influence behavior.