An outbreak of norovirus gastroenteritis in an Austrian hospital, winter 2006-2007

Associations of infection control measures and norovirus outbreak outcomes in healthcare settings: a systematic review and meta-analysis

BACKGROUND

Although most norovirus outbreaks in high-income countries occur in healthcare facilities, information on associations between control measures and outbreak outcomes in these settings is lacking.

METHODS

We conducted a systematic review/meta-analysis to assess associations between norovirus outbreak control measures and outcomes in hospitals and long-term care facilities (LTCFs), globally. Using regression analyses stratified by setting (hospital/LTCF), we compared durations, attack rates, and case counts for outbreaks in which control measures were reportedly implemented to those in which they were not.

RESULTS

We identified 102 papers describing 162 norovirus outbreaks. Control measures were reportedly implemented in 118 (73%) outbreaks and were associated with 0.6 (95% CI: 0.3-1.1) times smaller patient case counts and 0.7 (95% CI: 0.4, 1.0) times shorter durations in hospitals but 1.5 (95% CI: 1.1-2.2), 1.5 (95% CI: 1.0-2.1) and 1.6 (95% CI: 1.0-2.6) times larger overall, resident and staff case counts, respectively, and 1.4 (95% CI: 1.0-2.0) times longer durations in LTCFs.

CONCLUSIONS

Reported implementation of control measures was associated with smaller/shorter outbreaks in hospitals but larger/longer outbreaks in LTCFs. Control measures were likely implemented in response to larger/longer outbreaks in LTCFs, rather than causing them. Prospective observational or intervention studies are needed to determine effectiveness.

The Clinical and Economic Burden of Norovirus Gastroenteritis in the United States

BACKGROUND

Although norovirus outbreaks periodically make headlines, it is unclear how much attention norovirus may receive otherwise. A better understanding of the burden could help determine how to prioritize norovirus prevention and control.

METHODS

We developed a computational simulation model to quantify the clinical and economic burden of norovirus in the United States.

RESULTS

A symptomatic case generated $48 in direct medical costs, $416 in productivity losses ($464 total). The median yearly cost of outbreaks was $7.6 million (range across years, $7.5-$8.2 million) in direct medical costs, and $165.3 million ($161.1-$176.4 million) in productivity losses ($173.5 million total). Sporadic illnesses in the community (incidence, 10-150/1000 population) resulted in 14 118-211 705 hospitalizations, 8.2-122.9 million missed school/work days, $0.2-$2.3 billion in direct medical costs, and $1.4-$20.7 billion in productivity losses ($1.5-$23.1 billion total). The total cost was $10.6 billion based on the current incidence estimate (68.9/1000).

CONCLUSION

Our study quantified norovirus' burden. Of the total burden, sporadic cases constituted >90% (thus, annual burden may vary depending on incidence) and productivity losses represented 89%. More than half the economic burden is in adults ≥45, more than half occurs in winter months, and >90% of outbreak costs are due to person-to-person transmission, offering insights into where and when prevention/control efforts may yield returns.

Clinical pictures, treatments, and resource use of norovirus gastroenteritis in long-term care facilities: a survey with a chart review in Japan

BACKGROUND

Outbreaks of norovirus infection can have detrimental impacts on long-term care facilities. This study investigated the incidence, clinical picture, treatment and resource use of norovirus gastroenteritis in long-term care facilities.

METHODS

Nineteen facilities in Osaka and Kyoto, Japan participated in questionnaire surveys conducted between 2009 and 2011 regarding the incidence of norovirus gastroenteritis. From clinical charts, the characteristics, symptoms, and treatment of infected residents were analyzed. Total drug cost per infected resident was calculated by multiplying the unit price for each drug by the daily dose and the number of days administered and summing the costs for each drug (USD 1 = JPY 100).

RESULTS

Over the 3-year period, 8 outbreaks of norovirus gastroenteritis occurred in 6 facilities. The mean clinical course of 107 infected residents in five facilities that granted permission to examine patients' medical records was 4 days, with all but one resident presenting with vomiting and/or diarrhea, and 84 (79%) also presenting with associated symptoms. Of 107 infected residents, 72 (67%) were isolated. The proportion of infected residents isolated varied from 50 to 100% depending on the facility. Of the infected residents, 81 (76%) received some type of medication, the most common being infusion (67 patients, 63%) and antibiotics (30 patients, 28%). The median total cost of all drugs administered was USD 4.4, and the median drug cost per infected resident per day was USD 2.0. Total drug cost over the entire treatment period was the highest for antibiotics, at USD 8.6.

CONCLUSION

Clinical course was similar to those of norovirus cases examined at other long-term care facilities. The majority of infected residents received some type of medication. Although the economic burden was not large, not a few infected residents were given antibiotics, which are ineffective for norovirus.

[On Statistical Underreporting of Norovirus-Infections: Insights from Register Data of Two Local Public Health Authorities]

BACKGROUND

Only laboratory-confirmed norovirus (NoV) cases have to be notified to the Robert Koch Institute (RKI) since 2011, but not other, e. g. clinical-epidemiological cases. It can be assumed that the extent of underreporting of NoV cases in Germany has significantly increased since then.

OBJECTIVES

To discuss the extent of underreporting, we wanted to find out how many laboratory tests were carried out during gastroenteritis outbreaks. Furthermore, the significance of NoV outbreaks in occupational health is discussed.

MATERIALS AND METHODS

Of all pseudonymized gastroenteritis outbreak data reported to 2 local health authorities between 2011 and 2015, the proportion of NoV outbreaks and reported cases of infection among employees in hospitals and community facilities (nursing homes for the elderly, day-care centers, schools) confirmed by laboratory tests was calculated retrospectively.

RESULTS

Only a few gastroenteritis outbreaks in day-care centers were etiologically diagnosed, so that only 6% and less could be classified as NoV outbreaks. In nursing homes for the elderly, about half of the outbreaks were classified as NoV, in hospitals almost all of them. Employees accounted for up to 23% of those affected in NoV outbreaks.

CONCLUSIONS

The low level of laboratory diagnostics carried out during gastroenteritis outbreaks in day-care centers suggests a considerable number of hidden NoV cases. The significant proportion of staff relative to the total number of infected persons during the outbreaks highlights the importance of the burden of NoV outbreaks as a topic in occupational health. Further, large-scale prospective studies are needed to empirically substantiate these initial findings.

Variations in status of preparation of personal protective equipment for preventing norovirus gastroenteritis in long-term care facilities for the elderly

RATIONALE, AIM, AND OBJECTIVES

Residents of long-term care facilities are highly susceptible to norovirus gastroenteritis, and each facility is concerned about the need to implement norovirus infection control. Among control measures, personal protective equipment (PPE), such as disposable gloves and masks, plays a major role in reducing infectious spread. However, the preparation status of PPE in facilities before infection outbreaks has not been reported. The aim was to clarify the implementation status of preventive measures for norovirus gastroenteritis and the cost of preparing the necessary PPE in long-term care facilities.

METHOD

A questionnaire survey of facilities affiliated with the Kyoto Prefecture and Osaka Prefecture branches of the Japan Association of Geriatric Health Services Facilities was conducted. The survey items were the characteristics of the facility, whether preventive measures had been implemented for norovirus gastroenteritis from October through the following March in both 2009 and 2010, and the quantities and unit prices of PPE prepared for preventive measures.

RESULTS

Twenty-six (11.2%) of 232 surveyed facilities (as of August 2011) answered the survey. Among them, 24 (92.3%) in 2009 and 25 (96.2%) in 2010 reported having implemented preventive measures for norovirus gastroenteritis, while 21 facilities (80.8%) in 2009 and 22 facilities (84.6%) in 2010 had prepared PPE. The median total cost for preparing the PPE needed for the preventive measures was US $2601 (range US $221-9192) in 2009 and US $3904 (range US $305-6427) in 2010.

CONCLUSION

Although the results need careful interpretation because of the low response rate, most of the surveyed long-term care facilities had implemented preventive measures for norovirus gastroenteritis. However, the cost of preparing the PPE needed for the preventive measures varied among the facilities.

Cost analysis of an outbreak of Clostridium difficile infection ribotype 027 in a Dutch tertiary care centre

BACKGROUND

The economic impact of Clostridium difficile infection (CDI) on the healthcare system is significant. From May 2013 to May 2014, an outbreak of C. difficile ribotype 027 occurred in a Dutch tertiary care hospital, involving 72 patients. The primary aim of this study was to provide insight into the financial burden that this CDI outbreak brought upon this hospital.

METHODS

A retrospective analysis was performed to estimate the costs of a one-year-long C. difficile ribotype 027 outbreak. Medical charts were reviewed for patient data. In addition, all costs associated with the outbreak control measures were collected.

FINDINGS

The attributable costs of the whole outbreak were estimated to be €1,222,376. The main contributing factor was missed revenue due to increased length of stay of CDI patients and closure of beds to enable contact isolation of CDI patients (36%). A second important cost component was extra surveillance and activities of the Department of Medical Microbiology and Infection Control (25%).

CONCLUSION

To the authors' knowledge, this is the first study to provide insight into the attributable costs of CDI in an outbreak setting, and to delineate the major cost items. It is clear that the economic consequences of CDI are significant. The high costs associated with a CDI outbreak should help to justify the use of additional resources for CDI prevention and control.

Cost-Analysis of Seven Nosocomial Outbreaks in an Academic Hospital

OBJECTIVES

Nosocomial outbreaks, especially with (multi-)resistant microorganisms, are a major problem for health care institutions. They can cause morbidity and mortality for patients and controlling these costs substantial amounts of funds and resources. However, how much is unclear. This study sets out to provide a comparable overview of the costs of multiple outbreaks in a single academic hospital in the Netherlands.

METHODS

Based on interviews with the involved staff, multiple databases and stored records from the Infection Prevention Division all actions undertaken, extra staff employment, use of resources, bed-occupancy rates, and other miscellaneous cost drivers during different outbreaks were scored and quantified into Euros. This led to total costs per outbreak and an estimated average cost per positive patient per outbreak day.

RESULTS

Seven outbreaks that occurred between 2012 and 2014 in the hospital were evaluated. Total costs for the hospital ranged between €10,778 and €356,754. Costs per positive patient per outbreak day, ranged between €10 and €1,369 (95% CI: €49-€1,042), with a mean of €546 and a median of €519. Majority of the costs (50%) were made because of closed beds.

CONCLUSIONS

This analysis is the first to give a comparable overview of various outbreaks, caused by different microorganisms, in the same hospital and all analyzed with the same method. It shows a large variation within the average costs due to different factors (e.g. closure of wards, type of ward). All outbreaks however cost considerable amounts of efforts and money (up to €356,754), including missed revenue and control measures.

Use of ward closure to control outbreaks among hospitalized patients in acute care settings: a systematic review

BACKGROUND

Though often used to control outbreaks, the efficacy of ward closure is unclear. This systematic review sought to identify studies defining and describing ward closure in outbreak control and to determine impact of ward closure as an intervention on outbreak containment.

METHODS

We searched these databases with no language restrictions: MEDLINE, 1946 to 7 July 2014; EMBASE, 1974 to 7 July 2014; CINAHL, 1937 to 8 July 2014; and Cochrane Database of Systematic Reviews, 2005 to May 2014. We also searched the following: IndMED; LILACS; reference lists from retrieved articles; conference proceedings; and websites of the CDCP, the ICID, and the WHO. We included studies of patients hospitalized in acute care facilities; used ward closure as a control measure; used other control measures; and discussed control of the outbreak(s) under investigation. A component approach was used to assess study quality.

RESULTS

We included 97 English and non-English observational studies. None included a controlled comparison between ward closure and other interventions. We found that ward closure was often used as part of a bundle of interventions but could not determine its direct impact separate from all the other interventions whether used in parallel or in sequence with other interventions. We also found no universal definition of ward closure which was widely accepted.

CONCLUSIONS

With no published controlled studies identified, ward closure for control of outbreaks remains an intervention that is not evidence based and healthcare personnel will need to continue to balance the competing risks associated with its use, taking into consideration the nature of the outbreak, the type of pathogen and its virulence, mode of transmission, and the setting in which it occurs. Our review has identified a major research gap in this area.

Safety and tolerability of virucidal hand rubs: a randomized, double-blind, cross-over trial with healthy volunteers

BACKGROUND

The hands of the medical staff play an important role in transmission of pathogens in the health care environment. Hand hygiene is efficient, easy to perform and cost-effective. Safety, tolerability and acceptance of hand hygiene preparations play a major role in hand hygiene compliance, and apply, in particular, to formulations with high anti-viral activity.

AIM

Clinical trial to evaluate the safety and tolerability of different virucidal hand rubs.

METHODS

In a randomized, double-blind, four-period cross-over trial, healthy volunteers received three different virucidal hand rubs (P1-P3) and a reference product (R) in randomized sequence over a period of 4 days each with a washout period. The primary endpoint was skin barrier function measured by transepidermal water loss (TEWL) after application.

RESULTS

Twenty-two subjects (seven male, 15 female; median age 25, range 21-54) were randomized and started at least one period. TEWL was 22.5; 95 %-confidence interval (CI): 19.6-25.4 after P1, 16.3; 13.5-19.1 after P2, 16.4; 13.4-19.3 after P3, and 24.0; 21.1-27.0 after R; p < 0.0001. The percentage of subjects experiencing at least one adverse event (AE) was 86 % with P1, 25 % with P2, 89 % with P3 and 56 % with R. The majority of AEs were skin reactions classified as of mild severity. No serious AEs were observed.

CONCLUSIONS

Results were inconsistent. The number of AEs was higher than expected for all products. In summary, there is room for improvement both for hand rub development and the scientific approaches taken to practically and reproducibly evaluate hand rub safety and tolerability.

Norovirus

Norovirus, an RNA virus of the family Caliciviridae, is a human enteric pathogen that causes substantial morbidity across both health care and community settings. Several factors enhance the transmissibility of norovirus, including the small inoculum required to produce infection (<100 viral particles), prolonged viral shedding, and its ability to survive in the environment. In this review, we describe the basic virology and immunology of noroviruses, the clinical disease resulting from infection and its diagnosis and management, as well as host and pathogen factors that complicate vaccine development. Additionally, we discuss overall epidemiology, infection control strategies, and global reporting efforts aimed at controlling this worldwide cause of acute gastroenteritis. Prompt implementation of infection control measures remains the mainstay of norovirus outbreak management.

Economics and financing of vaccines for diarrheal diseases

The considerable burden of infectious disease-caused diarrhea around the world has motivated the continuing development of a number of vaccine candidates over the past several decades with some reaching the market. As with all major public health interventions, understanding the economics and financing of vaccines against diarrheal diseases is essential to their development and implementation. This review focuses on each of the major infectious pathogens that commonly cause diarrhea, the current understanding of their economic burden, the status of vaccine development, and existing economic evaluations of the vaccines. While the literature on the economics and financing of vaccines against diarrhea diseases is growing, there is considerable room for more inquiry. Substantial gaps exist for many pathogens, circumstances, and effects. Economics and financing studies are integral to vaccine development and implementation.

Spatial and temporal analyses to investigate infectious disease transmission within healthcare settings

Background

Healthcare-associated infections (HCAIs) cause significant morbidity and mortality worldwide, and outbreaks are often only identified after they reach high levels. A wide range of data is collected within healthcare settings; however, the extent to which this information is used to understand HCAI dynamics has not been quantified.

Aim

To examine the use of spatiotemporal analyses to identify and prevent HCAI transmission in healthcare settings, and to provide recommendations for expanding the use of these techniques.

Methods

A systematic review of the literature was undertaken, focusing on spatiotemporal examination of infectious diseases in healthcare settings. Abstracts and full-text articles were reviewed independently by two authors to determine inclusion.

Findings

In total, 146 studies met the inclusion criteria. There was considerable variation in the use of data, with surprisingly few studies (N = 22) using spatiotemporal-specific analyses to extend knowledge of HCAI transmission dynamics. The remaining 124 studies were descriptive. A modest increase in the application of statistical analyses has occurred in recent years.

Conclusion

The incorporation of spatiotemporal analysis has been limited in healthcare settings, with only 15% of studies including any such analysis. Analytical studies provided greater data on transmission dynamics and effective control interventions than studies without spatiotemporal analyses. This indicates the need for greater integration of spatiotemporal techniques into HCAI investigations, as even simple analyses provide significant improvements in the understanding of prevention over simple descriptive summaries.

An outbreak of norovirus infection in a bone marrow transplant unit

BACKGROUND

Norovirus is a single-stranded RNA virus belonging to the Caliciviridae family.

METHODS

Our observational cohort study aimed to describe a nosocomial outbreak of norovirus on a bone marrow transplant (BMT) unit.

RESULTS

Six of 8 BMT patients with increased liquid stools tested positive for norovirus: 4 had new onset diarrhea; 2 had acute exacerbations of chronic diarrhea caused by graft versus host disease. Eight non-BMT inpatients had norovirus infection, but 7 of these were community acquired; cumulative incidence rates in BMT and non-BMT units were 26% and 0.16%, respectively. In BMT patients, diarrhea (increased or new onset) lasted 6 to 33 days-durations shorter than those reported in sporadic BMT cases. All patients had private rooms and bathrooms. Five of 6 patients were on the BMT unit during their presumed incubation periods. Three were in adjacent rooms. Three nurses and 1 physician had symptoms compatible with norovirus infection, and all 4 worked while ill. The outbreak ended coincident with implementation of stricter infection control practices.

CONCLUSION

Norovirus appeared to spread in a BMT unit more avidly than it did among general medical patients. Explanations include prolonged diarrhea and viral excretion, long hospital stays of infected patients, rarity of empiric contact isolation for diarrhea, routine handling of liquid stool, and a closed community of health care workers.

The economic burden of patient safety targets in acute care: a systematic review

BACKGROUND

Our objective was to determine the quality of literature in costing of the economic burden of patient safety.

METHODS

We selected 15 types of patient safety targets for our systematic review. We searched the literature published between 2000 and 2010 using the following terms: "costs and cost analysis," "cost-effectiveness," "cost," and "financial management, hospital." We appraised the methodologic quality of potentially relevant studies using standard economic methods. We recorded results in the original currency, adjusted for inflation, and then converted to 2010 US dollars for comparative purposes (2010 US$1.00 = 2010 €0.76). The quality of each costing study per patient safety target was also evaluated.

RESULTS

We screened 1948 abstracts, and identified 158 potentially eligible studies, of which only 61 (39%) reported any costing methodology. In these 61 studies, we found wide estimates of the attributable costs of patient safety events ranging from $2830 to $10,074. In general hospital populations, the cost per case of hospital-acquired infection ranged from $2132 to $15,018. Nosocomial bloodstream infection was associated with costs ranging from $2604 to $22,414.

CONCLUSION

There are wide variations in the estimates of economic burden due to differences in study methods and methodologic quality. Greater attention to methodologic standards for economic evaluations in patient safety is needed.

Norovirus Monitoring in Bivalve Molluscs Harvested and Commercialized in Southern Italy

Norovirus (NoV) is the main cause of human nonbacterial gastroenteritis throughout the world. NoVs are classified into five genogroups: GI, GII, GIII, GIV, and GV. NoVs from GI and GII are the most commonly reported NoVs associated with human infections, and raw or undercooked shellfish have been identified as the main potential infection vehicle. European Commission Regulation 2073/2005 defines only bacteriological parameters for use as safety criteria for shellfish because reference methods for detection of viruses are lacking. From July 2007 to April 2010, 163 shellfish samples were collected in southern Italy from harvesting areas, authorized or nonauthorized retailers, and a restaurant after an outbreak of human gastroenteritis. The shellfish were analyzed for the presence of NoVs from GI and GII using the one-step real-time reverse transcription PCR protocol. A total of 94 shellfish samples (57.7%) were positive for the presence of NoV, and GII was the most frequently identified genogroup.

A review of nosocomial norovirus outbreaks: infection control interventions found effective

The purpose of this study was to review documented outbreaks of enteric illness associated with nosocomial norovirus infections and to identify modes of transmission, morbidity and mortality patterns, and recommendations for control. Searches of electronic databases, public health publications, and federal, state/provincial public health websites were completed for 1 January 2000 to 31 December 2010. Computer-aided searches of literature databases and systematic searches of government websites identified 54 relevant outbreak reports. Transmission routes included person-to-person (18.5%), foodborne (3.7%) and in the majority (77.8%) the route was unknown. Actions taken during the outbreak to control infection included restricting the movements of patients and staff (22.5%), enhanced environmental cleaning (13.6%) and hand hygiene (10.3%). Rapid identification of norovirus outbreaks in hospitals is vital for the immediate implementation of infection control measures and isolation of infected individuals in this mainly immunocompromised population. Studies that statistically evaluate infection control measures are needed.

Worldwide Outbreak Database: the largest collection of nosocomial outbreaks

Epidemiological findings of a single outbreak event may not be generalized; however, the characteristics of a typical outbreak can be determined on the basis of a large number of similar events. The Outbreak Database (http://www.outbreak-database.com) is the largest collection of nosocomial outbreaks currently available—and is still expanding. Articles are filed systematically, enabling those on a specific parameter of interest to be retrieved quickly. As such, this database is an extremely valuable tool on many medically related fronts, such as for educating other medical personnel, providing relevant information during the investigation of an acute outbreak, or addressing scientific-oriented questions. Several systematic reviews on a wide range of subjects, including sources of infections, types of pathogens, routes of transmission, appropriate infection control measures, and patients at risk of infection, have already been published based on information contained in this database. As this database may be used free of charge, all medical staff in the field of infection control, hygiene, and hospital epidemiology should be aware of its existence.