Guideline for the prevention and control of norovirus gastroenteritis outbreaks in healthcare settings

A narrative review of norovirus epidemiology, biology, and challenges to vaccine development

Norovirus is a leading cause of acute gastroenteritis (AGE) globally. AGE resulting from norovirus causes significant morbidity and mortality in countries of all income levels, particularly among young children and older adults. Prevention of norovirus AGE represents a unique challenge as the virus is genetically diverse with multiple genogroups and genotypes cocirculating globally and causing disease in humans. Variants of the GII.4 genotype are typically the most common genotype, and other genotypes cause varying amounts of disease year-to-year, with GII.2, GII.3, and GII.6 most prevalent in recent years. Noroviruses are primarily transmitted via the fecal-oral route and only a very small number of virions are required for infection, which makes outbreaks of norovirus extremely difficult to control when they occur. Settings like long-term care facilities, daycares, and hospitals are at high risk of outbreaks and can have very high attack rates resulting in substantial costs and disease burden. Severe cases of norovirus AGE are most common in vulnerable patient populations, such as infants, the elderly, and immunocompromised individuals, with available treatments limited to rehydration therapies and supportive care. To date, there are no FDA-approved norovirus vaccines; however, several candidates are currently in development. Given the substantial human and economic burden associated with norovirus AGE, a vaccine to prevent morbidity and mortality and protect vulnerable populations could have a significant impact on global public health.

Advances in wastewater analysis revealing the co-circulating viral trends of noroviruses and Omicron subvariants

Co-presence of enveloped and non-enveloped viruses is common both in community circulation and in wastewater. Community surveillance of infections requires robust methods enabling simultaneous quantification of multiple viruses in wastewater. Using enveloped SARS-CoV-2 Omicron subvariants and non-enveloped norovirus (NoV) as examples, this study reports a robust method that integrates electronegative membrane (EM) concentration, viral inactivation, and RNA preservation (VIP) with efficient capture and enrichment of the viral RNA on magnetic (Mag) beads, and direct detection of RNA on the beads. This method provided improved viral recoveries of 80 ± 4 % for SARS-CoV-2 and 72 ± 5 % for Murine NoV. Duplex reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays with newly designed degenerate primer-probe sets offered high PCR efficiencies (90-91 %) for NoV (GI and GII) targets and were able to detect as few as 15 copies of the viral RNA per PCR reaction. This technique, combined with duplex detection of NoV and multiplex detection of Omicron, successfully quantified NoV (GI and GII) and Omicron variants in the same sets of 94 influent wastewater samples collected from two large wastewater systems between July 2022 and June 2023. The wastewater viral RNA results showed temporal changes of both NoV and Omicron variants in the same wastewater systems and revealed an inverse relationship of their emergence. This study demonstrated the importance of a robust analytical platform for simultaneous surveillance of enveloped and non-enveloped viruses in wastewater. The ability to sensitively determine multiple viral pathogens in wastewater will advance applications of wastewater surveillance as a complementary public health tool.

Hygiene requirements for cleaning and disinfection of surfaces: recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute

This recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) addresses not only hospitals, but also outpatient health care facilities and compiles current evidence. The following criteria are the basis for the indications for cleaning and disinfection: Infectious bioburden and tenacity of potential pathogens on surfaces and their transmission routes, influence of disinfecting surface cleaning on the rate of nosocomial infections, interruption of cross infections due to multidrug-resistant organisms, and outbreak control by disinfecting cleaning within bundles. The criteria for the selection of disinfectants are determined by the requirements for effectiveness, the efficacy spectrum, the compatibility for humans and the environment, as well as the risk potential for the development of tolerance and resistance. Detailed instructions on the organization and implementation of cleaning and disinfection measures, including structural and equipment requirements, serve as the basis for their implementation. Since the agents for surface disinfection and disinfecting surface cleaning have been classified as biocides in Europe since 2013, the regulatory consequences are explained. As possible addition to surface disinfection, probiotic cleaning, is pointed out. In an informative appendix (only in German), the pathogen characteristics for their acquisition of surfaces, such as tenacity, infectious dose and biofilm formation, and the toxicological and ecotoxicological characteristics of microbicidal agents as the basis for their selection are explained, and methods for the evaluation of the resulting quality of cleaning or disinfecting surface cleaning are presented.

Viral gastroenteritis

Since the discovery of norovirus in 1972 as a cause of what was contemporarily known as acute infectious non-bacterial gastroenteritis, scientific understanding of the viral gastroenteritides has continued to evolve. It is now recognised that a small number of viruses are the predominant cause of acute gastroenteritis worldwide, in both high-income and low-income settings. Although treatment is still largely restricted to the replacement of fluid and electrolytes, improved diagnostics have allowed attribution of illness, enabling both targeted treatment of individual patients and prioritisation of interventions for populations worldwide. Questions remain regarding specific genetic and immunological factors underlying host susceptibility, and the optimal clinical management of patients who are susceptible to severe or prolonged manifestations of disease. Meanwhile, the worldwide implementation of rotavirus vaccines has led to substantial reductions in morbidity and mortality, and spurred interest in vaccine development to diminish the impact of the most prevalent viruses that are implicated in this syndrome.

Viral pathogen detection using multiplex gastrointestinal molecular panels: The pros and cons of viral target inclusion

Diagnosis of gastrointestinal infections has been revolutionized by the development of in vitro diagnostic (IVD) multiplex molecular panels for the detection of viral nucleic acids. In addition to a high degree of accuracy, these panels are commercially available and relatively simple to perform in the clinical laboratory. However, use of these panels must be carefully considered owing to the laboratory costs of the test, limited reimbursement, and potential for overuse. In this review from the Pan American Society for Clinical Virology, we focus on the viral components of GI multiplex panels (GIPs), presenting a brief overview of pathogens included on most panels and a discussion of advantages and challenges of the inclusion of viral targets on GIPs that should be considered before implementation in the clinical laboratory.

In vivo efficacy of alcohol based hand rubs against noroviruses: A novel standardized European test method simulating practical conditions

BACKGROUND

Non-enveloped viruses are particularly resistant to disinfectants, so to prevent and control the spread of virus infections, disinfectants with proven virucidal activity must be used. However, a test such as EN 1500, which uses an internal standard as reference treatment for determining the bactericidal efficacy of hand rubs, is still lacking. We aimed to establish a European standard for testing the in vivo efficacy of hand rubs against non-enveloped viruses.

METHOD

First, concentration and mode of application of ethanol as reference were determined. Afterwards, the efficacies of two commonly used hand rubs were compared to this reference. Hands of volunteers were contaminated with the murine norovirus strain S99.

RESULTS

70% wt/wt ethanol (2 x 3 mL in 2 x 30 seconds) was defined as internal reference treatment. The commercial ethanol based hand rub could significantly reduce the titre of norovirus in 30 seconds whereas a rub based on ethanol and propan-2-ol was significantly less effective compared to the reference.

CONCLUSION

We have established a possible standard for testing the in vivo efficacy of hand rubs against non-enveloped viruses using murine norovirus, a low contamination volume technique and ethanol as internal reference. Nevertheless our findings have to be confirmed in European ring trials.

Norovirus: An Overview of Virology and Preventative Measures

Norovirus (NoV) is an enteric non-enveloped virus which is the leading cause of gastroenteritis across all age groups. It is responsible for around 200,000 deaths annually and outbreaks are common in small communities such as educational and care facilities. 40% of all NoV outbreaks occur in long-term and acute-care facilities, forming the majority of outbreaks. Nosocomial settings set ideal environments for ease of transmission, especially due to the presence of immunocompromised groups. It is estimated to cost global economies around £48 billion a year, making it a global issue. NoV is transmitted via the faecal-oral route and infection with it results in asymptomatic cases or gastrointestinal disease. It has high mutational rates and this allows for new variants to emerge and be more resistant. The classification system available divides NoV into 10 genogroups and 49 genotypes based on whole amino acid sequencing of VP1 capsid protein and partial sequencing of RdRp, respectively. The most predominant genotypes which cause gastroenteritis in humans include GI.1 and GII.4, where GII.4 is responsible for more extreme clinical implications such as hospitalisation. In addition, GII.4 has been responsible for 6 pandemic strains, the last of which is the GII.4 Sydney (2012) variant. In recent years, the successful cultivation of HuNoV was reported in stem cell-derived human intestinal enteroids (HIEs), which promises to assist in giving a deeper understanding of its underlying mechanisms of infection and the development of more personalized control measures. There are no specific control measures against NoV, therefore common practices are used against it such as hand washing. No vaccine is available, but the HIL-214 candidate passed clinical phase 2b and shows promise.

Illuminating Human Norovirus: A Perspective on Disinfection of Water and Surfaces Using UVC, Norovirus Model Organisms, and Radiation Safety Considerations

Human noroviruses (HuNoVs) are a major cause of gastroenteritis and are associated with high morbidity because of their ability to survive in the environment and small inoculum size required for infection. Norovirus is transmitted through water, food, high touch-surfaces, and human-to-human contact. Ultraviolet Subtype C (UVC) light-emitting diodes (LEDs) can disrupt the norovirus transmission chain for water, food, and surfaces. Here, we illuminate considerations to be adhered to when picking norovirus surrogates for disinfection studies and shine light on effective use of UVC for norovirus infection control in water and air and validation for such systems and explore the blind spot of radiation safety considerations when using UVC disinfection strategies. This perspective also discusses the promise of UVC for norovirus mitigation to save and ease life.

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.

Norovirus disease among older adults

Norovirus, a leading cause of gastroenteritis outbreaks worldwide, results in substantial direct and indirect healthcare costs. Adults older than 65 years of age bear a significant proportion of the disease burden, and the disease course in this population is often more severe and protracted. In this narrative review, we discuss the epidemiology of norovirus infection, mechanisms of pathogenesis, and transmission pertinent to outbreaks along with infection prevention and control efforts. We also describe the clinical manifestations of norovirus disease with a focus on individuals older than 65 years of age, diagnosis and available treatment options, and the challenges and progress within vaccine development.

Norovirus outbreak amid COVID-19 in the United Kingdom; priorities for achieving control

Norovirus, an enteric virus primarily responsible for gastroenteritis outbreaks worldwide, is currently causing outbreaks around the United Kingdom during the COVID-19 pandemic. With an already exhausted health care system, the significant burden norovirus can have on the National Health Service, including economic and social burdens, is immense and cannot be tolerated. Primary challenges and priorities to be focused on due to the increase in norovirus outbreaks include a further depletion of health care services, increase cases in schools, nurseries, and care facilities, underreporting of the cases, and no effective vaccine being available. Therefore, it is essential to increase awareness about norovirus and its transmission in public, take necessary precautions, and increase reporting of cases. This article discusses the impact norovirus has during the COVID-19 pandemic, and the challenges, and recommendations to achieve control before it reaches epidemic levels.

Inactivation of human norovirus by chlorous acid water, a novel chlorine-based disinfectant

INTRODUCTION

Human norovirus (HuNoV) is a leading cause of infectious gastroenteritis. Since HuNoV shows resistance to alcohol, chlorine-based sanitizers are applied to decontaminate the virus on environmental surfaces. Chlorous acid water (CA) has been recently approved as a novel chlorine-based disinfectant categorized as a Type 2 OTC medicine in Japan. In this study, we aimed to evaluate the capability of CA to inactivate HuNoV.

METHODS

HuNoV (genogroups GII.2 and GII.4) was exposed to the test disinfectants including CA and sodium hypochlorite (NaClO), and the residual RNA copy was measured by reverse transcription quantitative PCR (RT-qPCR) after pretreatment with RNase. In addition, the log₁₀ reduction of HuNoV RNA copy number by CA and NaClO was compared in the presence of bovine serum albumin (BSA), sheep red blood cells (SRBC), polypeptone, meat extract or amino acids to evaluate the stability of these disinfectants under organic-matter-rich conditions.

RESULTS

In the absence of organic substances, CA with 200 ppm free available chlorine provided >3.0 log₁₀ reduction in the HuNoV RNA copy number within 5 min. Even under high organic matter load (0.3% each of BSA and SRBC or 0.5% polypeptone), 200 ppm CA achieved >3.0 log₁₀ reduction in HuNoV RNA copy number while less than 1.0 log₁₀ reduction was observed with 1,000 ppm sodium hypochlorite (NaClO) in the presence of 0.5% polypeptone. CA reacted with only cysteine, histidine and glutathione while NaClO reacted with all of the amino acids tested.

CONCLUSIONS

CA is an effective disinfectant to inactivate HuNoV under organic-matter-rich conditions.

Risk of environmental transmission of norovirus infection from prior room occupants

BACKGROUND

Environmental contamination of norovirus (NoV) is believed to be a significant source for further transmission in hospitals.

AIM

To investigate the risk of acquiring NoV in a cleaned room previously occupied by a patient with NoV infection. The risk of having a roommate with recent NoV infection was also assessed.

METHODS

In a retrospective cohort, comprising 33,788 room stays at five infectious Disease wards in southern Sweden from 2013 to 2018, the risk of acquiring NoV infection after admission to an exposed or non-exposed room was analysed with uni- and multivariable statistical analysis, controlling for age, colonization pressure and any roommate. RNA sequencing of the NoV strains involved in suspected room transmission was also performed.

RESULTS

Five of the 1106 patients exposed to a room with a prior occupant with NoV infection and 49 in the non-exposed group acquired NoV infection. An association between NoV acquisition was found in the univariable analysis (odds ratio (OR) 3.3, P=0.01), but not when adjusting for potential confounders (OR 1.9, P=0.2). Sequencing of the NoV samples showed that only two of the five exposed patients with acquired NoV infection were infected by identical strains to the prior room occupant, inferring a room transmission risk of 0.2% (95% confidence interval 0.05-0.78%). None of the 52 patients who shared room with a roommate with NoV symptoms resolved for ≥48 h acquired NoV infection.

CONCLUSIONS

In absolute terms, the risk of room transmission of NoV is low. Discontinuation of isolation ≥48 h after resolution of symptoms seems adequate.

Occupational Health and Safety Measures in Healthcare Settings during COVID-19: Strategies for Protecting Staff, Patients and Visitors

The COVID-19 (SARS-CoV-2) pandemic has profoundly impacted almost every aspect of healthcare systems worldwide, placing the health and safety of frontline healthcare workers at risk, and it still continues to remain an important public health challenge. Several hospitals have put in place strategies to manage space, staff, and supplies in order to continue to deliver optimum care to patients while at the same time protecting the health and safety of staff and patients. However, the emergence of the second and third waves of the virus with the influx of new cases continue to add an additional level of complexity to the already challenging situation of containing the spread and lowering the rate of transmission, thus pushing healthcare systems to the limit. In this narrative review paper, we describe various strategies including administrative controls, environmental controls, and use of personal protective equipment, implemented by occupational health and safety departments for the protection of healthcare workers, patients, and visitors from SARS-CoV-2 virus infection. The protection and safeguard of the health and safety of healthcare workers and patients through the implementation of effective infection control measures, adequate management of possible outbreaks and minimization of the risk of nosocomial transmission is an important and effective strategy of SARS-CoV-2 pandemic management in any healthcare facility. High quality patient care hinges on ensuring that the care providers are well protected and supported so they can provide the best quality of care to their patients.

Viral Acute Gastroenteritis in Special Populations

Viral acute gastroenteritis (AGE) is common and afflicts people of all ages. Nonviral causes of AGE are less common. Norovirus is a leading cause of sporadic cases and outbreaks of AGE across all ages. Universal rotavirus vaccination of infants has reduced frequency and severity of rotavirus AGE cases in children and indirectly reduced cases in older adults. Severe illness is more likely in persons at age extremes or with immunocompromising conditions. Viral causes of AGE can lead to protracted diarrheal illness in immunocompromised persons. Nucleic acid amplification tests are changing diagnostic testing algorithms.

Investigating awareness, fear and control associated with norovirus and other pathogens and pollutants using best-worst scaling

Pollutants found in the water and air environment represent an ever-growing threat to human health. Contact with some air-, water- and foodborne pathogens (e.g. norovirus) results in gastrointestinal diseases and outbreaks. For future risk mitigation, we aimed to measure people's awareness of waterborne and foodborne norovirus relative to other environment-associated pollutants (e.g. pesticides, bioaerosols, antibiotic resistant bacteria) and well-known risks (e.g. diabetes, dementia, terrorist attack). We used an online survey, which included a best-worst scaling component to elicit personal levels of control and fear prompted by norovirus relative to 15 other risks. There was a negative correlation between levels of fear vs. control for all 16 measured risks. Perceived infection control levels were higher amongst women compared to men and correlated with age and the level of qualification in both groups. Participants who had sought advice regarding the symptoms caused by norovirus appeared to have more control over the risks. Norovirus is associated with high levels of fear, however, the levels of control over it is low compared to other foodborne illnesses, e.g. Salmonella. Addressing this deficit in the public's understanding of how to control exposure to the pathogen in an important health need.

Practical recommendations for routine cleaning and disinfection procedures in healthcare institutions: a narrative review

Healthcare-associated infections (HAIs) are the most common adverse outcomes due to delivery of medical care. HAIs increase morbidity and mortality, prolong hospital stay, and are associated with additional healthcare costs. Contaminated surfaces, particularly those that are touched frequently, act as reservoirs for pathogens and contribute towards pathogen transmission. Therefore, healthcare hygiene requires a comprehensive approach whereby different strategies may be implemented together, next to targeted, risk-based approaches, in order to reduce the risk of HAIs for patients. This approach includes hand hygiene in conjunction with environmental cleaning and disinfection of surfaces and clinical equipment. This review focuses on routine environmental cleaning and disinfection including areas with a moderate risk of contamination, such as general wards. As scientific evidence has not yet resulted in universally accepted guidelines nor led to universally accepted practical recommendations pertaining to surface cleaning and disinfection, this review provides expert guidance for healthcare workers in their daily practice. It also covers outbreak situations and suggests practical guidance for clinically relevant pathogens. Key elements of environmental cleaning and disinfection, including a fundamental clinical risk assessment, choice of appropriate disinfectants and cleaning equipment, definitions for standardized cleaning processes and the relevance of structured training, are reviewed in detail with a focus on practical topics and implementation.

Sources of Airborne Norovirus in Hospital Outbreaks

BACKGROUND

Noroviruses are the major cause of viral gastroenteritis. Disease transmission is difficult to prevent and outbreaks in health-care facilities commonly occur. Contact with infected persons and contaminated environments are believed to be the main routes of transmission. However, noroviruses have recently been found in aerosols and airborne transmission has been suggested. The aim of our study was to investigate associations between symptoms of gastroenteritis and the presence of airborne norovirus, and to investigate the size of norovirus-carrying particles.

METHODS

Air sampling was repeatedly performed close to 26 patients with norovirus infections. Samples were analyzed for norovirus RNA by reverse transcription quantitative polymerase chain reaction. The times since each patient's last episodes of vomiting and diarrhea were recorded. Size-separating aerosol particle collection was performed.

RESULTS

Norovirus RNA was found in 21 (24%) of 86 air samples from 10 different patients. Only air samples during outbreaks, or before a succeeding outbreak, tested positive for norovirus RNA. Airborne norovirus RNA was also strongly associated with a shorter time period since the last vomiting episode (odds ratio 8.1; P = .04 within 3 hours since the last vomiting episode). The concentrations of airborne norovirus ranged from 5-215 copies/m3, and detectable amounts of norovirus RNA were found in particles <0.95 µm and >4.51 µm.

CONCLUSIONS

The results suggest that recent vomiting is the major source of airborne norovirus and imply a connection between airborne norovirus and outbreaks. The presence of norovirus RNA in submicrometre particles indicates that airborne transmission can be an important transmission route.

Norovirus outbreaks on college and university campuses

Objective: To describe norovirus outbreaks at colleges and universities. Participants: None. Conducted September 2016 to March 2018. Methods: College and university norovirus outbreaks reported to the US National Outbreak Reporting System (NORS, 2009-2016) or published and indexed by EMBASE, PubMed, and Web of Science (1985-2017) were analyzed. Results: Seventy-seven norovirus outbreaks were reported to NORS and 23 were identified in the systematic literature review. Outbreaks occurred more frequently during the beginning of the school year (September-February). NORS outbreaks were more often spread by person-to-person transmission (61%) and, in published outbreaks, by food (57%). The reported exposures of published outbreaks were campus dining (n = 8) and ill food service workers (n = 7). Higher attack rates were associated with smaller on-campus population size, social networks or residences, and specific food exposures. Common control measures were communal area disinfection and health/hygiene education. Conclusions: Recommendations summarized to prevent and control norovirus outbreaks at colleges or universities.

Norovirus in health care and implications for the immunocompromised host

PURPOSE OF REVIEW

The majority of norovirus outbreaks in the United States occur in healthcare facilities. With the growing population of immunocompromised hosts who are in frequent contact with healthcare facilities, norovirus is not only a threat to hospitals and nursing homes but also to these individuals. This review summarizes the impact of norovirus infection on healthcare facilities and immunocompromised hosts.

RECENT FINDINGS

The natural history of norovirus infection in immunocompromised individuals remains poorly understood. Although host immune responses play a critical role in reducing duration of viral shedding and viral load in norovirus-infected individuals, why some immunocompromised patients spontaneously recover while others develop a chronic and protracted course of illness remains unclear. Norovirus outbreaks occur in healthcare facilities because the virus is highly contagious, resistant to disinfection and efficiently transmitted. The use of real-time metagenomic next-generation sequencing and phylogenetic analyses has provided valuable information on transmission patterns in complex hospital-associated norovirus outbreaks. The development of human intestinal enteroid cultures enables the determination of effectiveness of disinfectants against human noroviruses, circumventing the validity questions with surrogate virus models due to differences in susceptibility to inactivation and disinfectants.

SUMMARY

Metagenomics next-generation sequencing can enhance our understanding of norovirus transmission and lead to more timely mitigation strategies to curb norovirus outbreaks in healthcare facilities. With new in-vitro cultivation methods for human noroviruses, candidate vaccines and effective antivirals could be available in the near future.

Examining the inclusion of patients and their family members in infection prevention and control policies and guidelines across Bangladesh, Indonesia, and South Korea

BACKGROUND

Although familial involvement during inpatient care is not uncommon in western countries, the types of caring activities that family members in Asian countries provide are significantly different. These activities may place the family member at risk from a health care-associated infection. This study aimed to examine whether the role of patients' families has been accounted for in the infection prevention and control (IPC) guidelines and policy, using examples from Bangladesh (low-income country), Indonesia (middle-income country), and South Korea (high-income country).

METHODS

The World Health Organization website and Institutional Repository for Information Sharing, Centers for Disease Control and Prevention website, Australian Government Web Archive, Open Grey, Grey Matters, World Bank, and advanced Google search, as well as the Health Department/Ministry of Health websites for each target country and 4 western countries (Australia, Canada, England, and the United States) were searched. Other databases, such as Embase, Medline, CINAHL, Global Health, ProQuest databases, Google scholar, Web of Science, and Scopus were also searched. This was to review the reflection of the cultural influence in IPC policies/guidelines by reviewing those from the global organizations, which are often used as a blueprint for policy development, as well as those from western countries, which hold different cultures in care arrangement. Search was conducted with attention to the key areas: definition and role of carer in the acute health care facility, involvement of patients/family members in IPC activities, patient and family member hand hygiene, and IPC education.

RESULTS

Ninety-two articles were identified based on the criteria for the study. Only 6 acknowledged that care is provided to hospitalized patients by their family members, and only 1 recommended that family members receive the same level of training as health care workers on IPC precautions. Other guides recommended the provision of information on IPC measures as means of patient involvement in the IPC program. Recognition of family caregivers or inclusion of them in the IPC strategies was not included in the target countries' guidelines.

CONCLUSIONS

Although health care workers are the primary actors when it comes to providing care in acute health care settings, it is important to expand the IPC guides by considering the role of other caregivers. Policies and guidelines should reflect the cultural influence over healthcare. This is especially true when cultural values strongly influence over healthcare arrangements and the healthcare accommodates these cultural influences in the practice. Further work needs to be undertaken on the level of training/education provided to family members in Bangladesh, Indonesia, and South Korea.

Comparison of estimated norovirus infection risk reductions for a single fomite contact scenario with residual and nonresidual hand sanitizers

BACKGROUND

The purpose of this study was to relate experimentally measured log₁₀ human norovirus reductions for a nonresidual (60% ethanol) and a residual (quaternary ammonium-based) hand sanitizer to infection risk reductions.

METHODS

Human norovirus log₁₀ reductions on hands for both sanitizers were experimentally measured using the ASTM International Standard E1838-10 method, with modification. Scenarios included product application to: (1) inoculated fingerpads with 30- and 60-second contact times, and (2) hands followed by inoculation with human norovirus immediately and 4 hours later. Hand sanitizer efficacies were used in a mathematical model estimating norovirus infection risk from a single hand-to-fomite contact under low and high environmental contamination conditions.

RESULTS

The largest log₁₀ reductions for the residual and nonresidual hand sanitizers were for a 60-second contact time, reducing infection risk by approximately 99% and 85%, respectively. Four hours after application, the residual hand sanitizer reduced infection risks by 78.5% under high contamination conditions, whereas the nonresidual hand sanitizer offered no reduction.

DISCUSSION

Log₁₀ virus and infection risk reductions were consistently greater for the residual hand sanitizer under all scenarios. Further data describing residual hand sanitizer efficacy with additional contamination or tactile events are needed.

CONCLUSIONS

Residual antinoroviral hand sanitizers may reduce infection risks for up to 4 hours.

Colloidal Silicon Dioxide in Tablet form (Carbowhite) Efficacy in Patients with Acute Diarrhea: Results of Randomized, Double-Blind, Placebo-Controlled, Multi-Center Study

The acute diarrhea is a wide-spread disease. The prescription of enterosorbents is appropriate as a primary measure for the treatment of the acute diarrhea for effective prevention of the fluid and electrolyte loss, as well as method for symptom relief of the attack of the disease. Aim of the study - the antidiarrheal efficacy and safety study of high-dispersion silicon dioxide enterosorbent in tablet dosage form in patients with acute diarrhea. This was randomized, double-blind, placebo-controlled, 4-center study. Acute diarrhea was defined as three and more episodes of watery stool per day either during 48 hours or less before study entry in the patients having normal stool recently. It has been postulated that symptoms and signs of acute diarrhea have to be caused by direct infection of the gastrointestinal tract and did not associated with moderate-to-severe systemic states. 144 patients with established acute diarrhea were randomized into treatment group (enterosorbent "Carbowhite", n = 120) or placebo group. Date collection including severity diarrhea, systemic symptoms was performed at baseline and daily during 7 days. Stool examination and serological assay were performed at baseline. The primary end points were declared as time to complete recovery from acute diarrhea. It has been found that the use of the siliceous enterosorbent ("Carbowhite") allowed to reduce (p < 0.001) the treatment period averagely for 0.9 days (95% confidence interval 0.5-1.2 days) in comparison with placebo. Data of safety monitoring has revealed that both patient groups had negative stool culture, while initiation of antibiotic treatment was run more frequently in placebo group (8.3%) compared to investigational product group (4.1%, P = 0.044). The siliceous enterosorbent "Carbowhite" was well tolerated and reduced the recovery time of the acute episode of the diarrhea in the clinically significant form.

Ozone efficacy for the control of airborne viruses: Bacteriophage and norovirus models

This study was designed to test the efficacy of an air treatment using ozone and relative humidity (RH) for the inactivation of airborne viruses. Four phages (φX174, PR772, MS2 and φ6) and one eukaryotic virus (murine norovirus MNV-1) were exposed to low ozone concentrations (1.23 ppm for phages and 0.23 ppm for MNV-1) and various levels of RH for 10 to 70 minutes. The inactivation of these viruses was then assessed to determine which of the tested conditions provided the greatest reduction in virus infectivity. An inactivation of at least two orders of magnitude for φX174, MS2 and MNV-1 was achieved with an ozone exposure of 40 minutes at 85% RH. For PR772 and φ6, exposure to the reference condition at 20% RH for 10 minutes yielded the same results. These findings suggest that ozone used at a low concentration is a powerful disinfectant for airborne viruses when combined with a high RH. Air treatment could therefore be implemented inside hospital rooms ventilated naturally.

Quantifying the roles of vomiting, diarrhea, and residents vs. staff in norovirus transmission in U.S. nursing home outbreaks

The role of individual case characteristics, such as symptoms or demographics, in norovirus transmissibility is poorly understood. Six nursing home norovirus outbreaks occurring in South Carolina, U.S. from 2014 to 2016 were examined. We aimed to quantify the contribution of symptoms and other case characteristics in norovirus transmission using the reproduction number (R_Ei) as an estimate of individual case infectivity and to examine how transmission changes over the course of an outbreak. Individual estimates of R_Ei were calculated using a maximum likelihood procedure to infer the average number of secondary cases generated by each case. The associations between case characteristics and R_Ei were estimated using a weighted multivariate mixed linear model. Outbreaks began with one to three index case(s) with large estimated R_Ei’s (range: 1.48 to 8.70) relative to subsequent cases. Of the 209 cases, 155 (75%) vomited, 164 (79%) had diarrhea, and 158 (76%) were nursing home residents (vs. staff). Cases who vomited infected 2.12 (95% CI: 1.68, 2.68) times the number of individuals as non-vomiters, cases with diarrhea infected 1.39 (95% CI: 1.03, 1.87) times the number of individuals as cases without diarrhea, and resident-cases infected 1.53 (95% CI: 1.15, 2.02) times the number of individuals as staff-cases. Index cases tended to be residents (vs. staff) who vomited and infected considerably more secondary cases compared to non-index cases. Results suggest that individuals, particularly residents, who vomit are more infectious and tend to drive norovirus transmission in U.S. nursing home norovirus outbreaks. While diarrhea also plays a role in norovirus transmission, it is to a lesser degree than vomiting in these settings. Results lend support for prevention and control measures that focus on cases who vomit, particularly if those cases are residents.

The majority of all norovirus outbreaks reported to the CDC occur in long-term care facilities (LTCFs), including nursing homes, where older residents are at risk for more severe or prolonged infection. Because there is currently no publicly available norovirus vaccine, sound control measures are key to controlling norovirus outbreaks, but there is little evidence that standard control measures are effective in reducing the size and/or duration of LTCF norovirus outbreaks. Hence, studies leading to a better understanding of disease spread and prevention of additional cases, and thus more effective control measures, are needed. To this end, we aimed to quantify factors associated with norovirus transmission and to examine how transmission changes over the course of an outbreak. We show that vomiting and, to a lesser extent, diarrhea are critical in initiating and sustaining norovirus transmission in U.S. nursing home norovirus outbreaks. We also show that nursing home residents, rather than staff, are the primary drivers of transmission. Results suggest that control measures focusing on cases who vomit, particularly if those cases are residents, would be most effective at curtailing norovirus transmission in these settings.

Successful control of norovirus outbreak in a pediatric ward with multi-bed rooms

BACKGROUND

Norovirus outbreaks in health care facilities are difficult to prevent and control.

METHODS

We describe a norovirus outbreak that occurred in a single pediatric ward with multi-bed rooms.

RESULTS

The outbreak began with 4 clustered cases with acute diarrhea in a pediatric ward between December 22 and 25, 2017. A total of 10 cases were identified during the outbreak, with a cumulative incidence of 8.77%. The median age of the cases was 10 months. Symptoms lasted for a median of 7.5 days, and norovirus shed in stool for a median of 19.5 days. The first 5 cases consecutively developed diarrhea; 4 of them were in the same room. The sixth case, which was linked with the clustered cases, had stayed in the intensive care unit and infected 3 other patients during the stay. After these 4 cases were transferred back to the ward, an additional patient was infected. Strict infection control measures were implemented, and the outbreak was successfully terminated 24 days after the initial case.

CONCLUSIONS

Controlling norovirus outbreak in a pediatric ward with multi-bed rooms is challenging. Early detection of the outbreak and prompt implementation of strict infection control measures are critical.

Efficient management of a norovirus outbreak causing gastroenteritis in two hotels in Spain, 2014

OBJECTIVES

To determine the aetiological agent causing a gastroenteritis outbreak in two hotels in Majorca (Spain) on August and September 2014.

METHODS

An epidemiological study was carried out. Environmental and stool samples were analyzed for different pathogens, including norovirus.

RESULTS

Epidemiological analysis detected 79 cases among the tourists hosted in the affected hotels over the period 18th August to 3rd September. They included 52 (attack rate: 6.4%) and 27 (attack rate: 3.0%) cases in hotel A and B, respectively. Seven of the staff members were also affected. Microbiological analyses detected genotype 2 norovirus in patient's stool samples, in rooms and in common areas' surfaces. The specific control plan rapidly implemented at the beginning of the outbreak, and further adapted for norovirus elimination, allowed to control the outbreak.

CONCLUSIONS

Our study demonstrates that the outbreak was caused by genotype 2 norovirus, and reflects the importance of a rapid analysis and response for its control.

Viruses in the Built Environment (VIBE) meeting report

BACKGROUND

During a period of rapid growth in our understanding of the microbiology of the built environment in recent years, the majority of research has focused on bacteria and fungi. Viruses, while probably as numerous, have received less attention. In response, the Alfred P. Sloan Foundation supported a workshop entitled "Viruses in the Built Environment (VIBE)," at which experts in environmental engineering, environmental microbiology, epidemiology, infection prevention, fluid dynamics, occupational health, metagenomics, and virology convened to synthesize recent advances and identify key research questions and knowledge gaps regarding viruses in the built environment.

RESULTS

Four primary research areas and funding priorities were identified. First, a better understanding of viral communities in the built environment is needed, specifically which viruses are present and their sources, spatial and temporal dynamics, and interactions with bacteria. Second, more information is needed about viruses and health, including viral transmission in the built environment, the relationship between virus detection and exposure, and the definition of a healthy virome. The third research priority is to identify and evaluate interventions for controlling viruses and the virome in the built environment. This encompasses interactions among viruses, buildings, and occupants. Finally, to overcome the challenge of working with viruses, workshop participants emphasized that improved sampling methods, laboratory techniques, and bioinformatics approaches are needed to advance understanding of viruses in the built environment.

CONCLUSIONS

We hope that identifying these key questions and knowledge gaps will engage other investigators and funding agencies to spur future research on the highly interdisciplinary topic of viruses in the built environment. There are numerous opportunities to advance knowledge, as many topics remain underexplored compared to our understanding of bacteria and fungi. Video abstract.

Prospective, Real-time Metagenomic Sequencing During Norovirus Outbreak Reveals Discrete Transmission Clusters

BACKGROUND

Norovirus outbreaks in hospital settings are a common challenge for infection prevention teams. Given the high burden of norovirus in most communities, it can be difficult to distinguish between ongoing in-hospital transmission of the virus and new introductions from the community, and it is challenging to understand the long-term impacts of outbreak-associated viruses within medical systems using traditional epidemiological approaches alone.

METHODS

Real-time metagenomic sequencing during an ongoing norovirus outbreak associated with a retrospective cohort study.

RESULTS

We describe a hospital-associated norovirus outbreak that affected 13 patients over a 27-day period in a large, tertiary, pediatric hospital. The outbreak was chronologically associated with a spike in self-reported gastrointestinal symptoms among staff. Real-time metagenomic next-generation sequencing (mNGS) of norovirus genomes demonstrated that 10 chronologically overlapping, hospital-acquired norovirus cases were partitioned into 3 discrete transmission clusters. Sequencing data also revealed close genetic relationships between some hospital-acquired and some community-acquired cases. Finally, this data was used to demonstrate chronic viral shedding by an immunocompromised, hospital-acquired case patient. An analysis of serial samples from this patient provided novel insights into the evolution of norovirus within an immunocompromised host.

CONCLUSIONS

This study documents one of the first applications of real-time mNGS during a hospital-associated viral outbreak. Given its demonstrated ability to detect transmission patterns within outbreaks and elucidate the long-term impacts of outbreak-associated viral strains on patients and medical systems, mNGS constitutes a powerful resource to help infection control teams understand, prevent, and respond to viral outbreaks.

Monitoring telehealth vomiting calls as a potential public health early warning system for seasonal norovirus activity in Ontario, Canada

Norovirus is a predominant cause of infectious gastroenteritis in countries worldwide [1-5]. It accounts for approximately 50% of acute gastroenteritis (AGE) and >90% of viral gastroenteritis outbreaks [6, 7]. The incubation period ranges between 10 and 48 h and illness duration is generally 1-3 days with self-limiting symptoms; however, this duration is often longer (e.g. 4-6 days) in vulnerable populations such as hospital patients or young children [2, 8]. Symptomatic infection of norovirus presents as acute vomiting, diarrhoea, abdominal cramps and nausea, with severe vomiting and diarrhoea (non-bloody) being most common [2, 5, 9].

State-level adoption of national guidelines for norovirus outbreaks in health care settings

BACKGROUND

Clinical decision support (CDS) systems can help investigators use best practices when responding to outbreaks, but variation in guidelines between jurisdictions can make such systems hard to develop and implement. This study aimed to identify (1) the extent to which state-level guidelines adhere to national recommendations for norovirus outbreak response in health care settings and (2) the impact of variation between states on outbreak outcomes.

METHODS

State guidelines were obtained from Internet searches and direct contact with state public health officials in early 2016. Outcomes from norovirus outbreaks that occurred in 2015 were compared using data from the National Outbreak Reporting System.

RESULTS

Guidelines were obtained from 41 of 45 (91%) state health departments that responded to queries or had guidelines available on their Web sites. Most state guidelines addressed each of the national recommendations, but specific guidance varied considerably. For example, among 36 states with guidance on numbers of stool specimens to collect, there were 21 different recommendations. Furthermore, having guidelines consistent with national recommendations was associated with fewer outbreaks reported and more outbreaks with confirmed etiology.

CONCLUSIONS

This study identified substantial variation in state health care-associated norovirus outbreak response guidelines, which must be considered when developing related CDS systems. More research is needed to understand why this variation exists, how it impacts outbreak outcomes, and where improvements in evidence-based recommendations and communication of national guidance are needed.

Viral gastroenteritis

Enteric viruses, particularly rotaviruses and noroviruses, are a leading cause of gastroenteritis worldwide. Rotaviruses primarily affect young children, accounting for almost 40% of hospital admissions for diarrhoea and 200 000 deaths worldwide, with the majority of deaths occurring in developing countries. Two vaccines against rotavirus were licensed in 2006 and have been implemented in 95 countries as of April, 2018. Data from eight high-income and middle-income countries showed a 49-89% decline in rotavirus-associated hospital admissions and a 17-55% decline in all-cause gastroenteritis-associated hospital admissions among children younger than 5 years, within 2 years of vaccine introduction. Noroviruses affect people of all ages, and are a leading cause of foodborne disease and outbreaks of gastroenteritis worldwide. Prevention of norovirus infection relies on frequent hand hygiene, limiting contact with people who are infected with the virus, and disinfection of contaminated environmental surfaces. Norovirus vaccine candidates are in clinical trials; whether vaccines will provide durable protection against the range of genetically and antigenically diverse norovirus strains remains unknown. Treatment of viral gastroenteritis is based primarily on replacement of fluid and electrolytes.

Detection of Norovirus by BD MAX™, Xpert® Norovirus, and xTAG® Gastrointestinal Pathogen Panel in stool and vomit samples

BACKGROUND

Norovirus is a leading cause of infectious gastroenteritis, characterized by outbreaks of diarrhoea and vomiting in closed settings. Nucleic acid amplification tests allow rapid and sensitive laboratory diagnosis of norovirus, with a number of commercial platforms now available.

OBJECTIVES

Evaluate the performance of the Becton Dickinson BD-MAX™System, Cepheid Xpert® Norovirus Assay, and Luminex xTAG® Gastrointestinal Pathogen Panel (GPP) for norovirus detection in stool. Assess the performance of the Xpert® Norovirus Assay and BD-MAX™ in vomit samples.

STUDY DESIGN

163 diarrhoeal stool samples were tested on four diagnostic systems (laboratory-defined real time RT-PCR (assigned as gold standard), BD MAX™, Xpert® Norovirus Assay, and xTAG® GPP). A further 70 vomit samples were tested on the Xpert and BD MAX platforms.

RESULTS

In stool, sensitivity and specificity of the BD-MAX™ was 96.8% and 100%, for Xpert® Norovirus Assay was 91.9% and 100%, and for xTAG® GPP was 79.0% and 87.1%. In vomit samples positive and negative percent agreement was 95.6% and 92.0%, between the BD-MAX™ and Xpert® Norovirus.

CONCLUSIONS

The BD-MAX™ System with user defined settings and the Xpert® Norovirus Assay showed acceptable sensitivity and specificity for detection of norovirus from stool and vomit. The xTAG GPP assay was less reliable for norovirus detection but can detect a number of other clinically useful enteropathogens. Clinical laboratories must consider skill mix, budget, and sample throughput to determine the best fit for their service.

Temporal Relationship Between Healthcare-Associated and Nonhealthcare-Associated Norovirus Outbreaks and Google Trends Data in the United States

Healthcare-associated norovirus outbreaks increase later but have a more pronounced seasonality than nonhealthcare norovirus outbreaks. Healthcare-associated norovirus outbreaks had higher correlation with Google Trends activity than nonhealthcare outbreaks (R2=0.68 vs 0.39). Google Trends data may have the potential to supplement existing norovirus surveillance due to its real-time availability.

Infect Control Hosp Epidemiol 2018;39:355–358

Risk factors for hospital norovirus outbreaks: impact of vomiting, genotype, and multi-occupancy rooms

BACKGROUND

Norovirus is frequently introduced to the hospital and is a frequent cause of hospital outbreaks. Recognition of the factors that facilitate or impede norovirus transmission is an important step to effectively prevent hospital outbreaks.

AIM

To investigate risk factors for norovirus outbreaks in hospital settings.

METHODS

Clinical data, ward setting, and norovirus genotype were collected from all 65 norovirus-positive index cases in outbreaks and all 186 sporadic norovirus cases at 192 wards in southern Sweden during 2010-2012 in a nested case-control study. Uni- and multivariate statistical analyses were conducted.

FINDINGS

Outbreak was independently associated with the number of patients sharing a room with the norovirus case (odds ratio (OR): 1.9 per additional patient in the room; P < 0.01), vomiting (OR: 2.6; P = 0.04), age >80 years (OR: 3.2; P < 0.01), comorbidity (OR: 2.3; P = 0.05), and onset of symptoms after admission to the ward (OR: 3.5; P < 0.01) in the multivariate analysis. Infection with genotype GII.4 was found to be strongly associated with outbreak in the univariate analysis (OR: 5.7; P < 0.01). Moreover, associations between GII.4 and vomiting (OR: 2.5; P = 0.01) and old age (OR: 4.3: P < 0.01) were found.

CONCLUSION

This is the first study to investigate clinical, ward and genotype risk factors for norovirus hospital outbreaks. Recognition of these factors may help direct and prioritize infection control actions based on the outbreak risk. The results also suggest that the outbreak association with GII.4 partly may be explained by an enhanced ability to induce vomiting.

High Hand Contamination Rates During Norovirus Outbreaks in Long-Term Care Facilities

We examined norovirus contamination on hands of ill patients during 12 norovirus outbreaks in 12 long-term care facilities (LTCFs). The higher frequency and norovirus titers on hands of residents compared to hands of heathcare workers highlights the importance of adhering to appropriate hand hygiene practices during norovirus outbreaks in LTCFs. Infect Control Hosp Epidemiol 2018;39:219-221.

Norovirus and Clostridium difficile outbreaks: squelching the wildfire

PURPOSE OF REVIEW

Gastrointestinal outbreaks in the healthcare setting cause increased morbidity and mortality in an already vulnerable population. Optimization of infection prevention measures can be a challenge in healthcare settings. This review describes new literature that may change the traditional infection prevention approach to such outbreaks.

RECENT FINDINGS

Asymptomatic carriers of both norovirus and Clostridium difficile can pose risk of transmission to others and the environment. Rapid recognition and diagnosis can decrease the extent of an outbreak. No-touch technologies for environmental disinfection are new and effective tools. Infection prevention consultant services and systems redesign can augment efforts to control baseline infection rates and outbreaks. Antimicrobial stewardship continues to be essential to prevent C. difficile infection.

SUMMARY

New approaches are needed to stem the tide of norovirus and C. difficile clusters and outbreaks in healthcare settings. Accurate recognition, testing, and implementation of infection prevention measures can be supported with rapid testing modalities, access to updated guidelines and no-touch disinfection systems. The work-environment culture should be carefully assessed and restructured using human engineering models to promote effective infection prevention practices. Antimicrobial stewardship initiatives are needed at the bedside and at national levels.

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.

Norovirus Infection in Older Adults: Epidemiology, Risk Factors, and Opportunities for Prevention and Control

Norovirus is the leading cause of acute gastroenteritis. In older adults, it is responsible for an estimated 3.7 million illnesses; 320,000 outpatient visits; 69,000 emergency department visits; 39,000 hospitalizations; and 960 deaths annually in the United States. Older adults are particularly at risk for severe outcomes, including prolonged symptoms and death. Long-term care facilities and hospitals are the most common settings for norovirus outbreaks in developed countries. Diagnostic platforms are expanding. Several norovirus vaccines in clinical trials have the potential to reap benefits. This review summarizes current knowledge on norovirus infection in older adults.

2017 Infectious Diseases Society of America Clinical Practice Guidelines for the Diagnosis and Management of Infectious Diarrhea

These guidelines are intended for use by healthcare professionals who care for children and adults with suspected or confirmed infectious diarrhea. They are not intended to replace physician judgement regarding specific patients or clinical or public health situations. This document does not provide detailed recommendations on infection prevention and control aspects related to infectious diarrhea.

Prospective cohort study to investigate the burden and transmission of acute gastroenteritis in care homes: a study protocol

INTRODUCTION

Noroviruses are the leading cause of acute gastroenteritis in all age groups, but illness is more severe and causes excess mortality in the elderly, particularly those in long-term care. The total burden of norovirus disease in the elderly in the UK is poorly defined; no current surveillance programmes systematically or accurately quantify norovirus infection in those living in care homes. The aim of this study is to evaluate an enhanced surveillance system for acute gastroenteritis among the elderly in care homes.

METHODS AND ANALYSIS

We will conduct this prospective cohort study in care homes in North West England; residents and staff at study care homes will be asked to participate. We will prospectively enrol a cohort of participants in an enhanced surveillance system to capture the incidence of acute gastroenteritis and use multiplex PCR to detect pathogens. We will sample symptomatic and non-symptomatic participants to understand characteristics of norovirus disease and susceptibility to infection. We will generate novel data on transmission dynamics by collecting data on the pattern of interactions within care homes using electronic proximity sensors. Comparisons of outbreak and non-outbreak periods will be used to quantify the impact of norovirus outbreaks on care homes.

ETHICS AND DISSEMINATION

The study has been approved by the North West-Greater Manchester South NHS Research Ethics Committee (REC Reference: 16/NW/0541). Study outputs will be disseminated through scientific conferences and peer-reviewed publications. This study will provide detailed insight on the burden and aetiology of acute gastroenteritis in care homes, in addition to generating novel data on transmission dynamics and risks. The study will identify areas for improving infection control practice and allow more accurate modelling of the introduction of interventions such as vaccination.

Norovirus Infections in Long-Term Care Facilities

Noroviruses have emerged as one of the leading causes of viral gastroenteritis worldwide, affecting community-dwelling and institutionalized older adults. Recent global epidemics present a growing challenge to the healthcare system and to long-term care facilities. Noroviruses spread readily and rapidly through multiple routes (e.g., person-to-person contact, contact with contaminated surfaces, airborne dissemination of vomitus) and thus are able to sustain an epidemic efficiently and successfully. Although norovirus gastroenteritis is a short self-limited illness in healthy immunocompetent individuals, it can result in significant morbidity and mortality in vulnerable compromised persons such as frail elderly persons and older residents of nursing homes. Diagnosis is made by clinical assessment and confirmed primarily by stool evaluation using polymerase chain reaction. Treatment is confined to supportive measures. Public health prevention and control strategies provide guidance regarding surveillance and the necessary steps to curb the clinical effect and spread of norovirus infections in various settings, including long-term care.

Hospital-Associated Infections

Hospital-associated infection (HAI) in immunocompromised patients can result in high rates of morbidity and mortality. Infections caused by multidrug-resistant organisms (MDROs) are especially worrisome because of the limited choice of remaining antibiotics available when a patient becomes colonized or infected with an MDRO. It is therefore important that immunocompromised patients be cared for in an environment that limits the risk for acquiring infections. However, with healthcare being increasingly delivered in settings other than the traditional inpatient hospital wards, a bigger effort will need to be set forth to prevent or rapidly diagnose HAI. The last few years have seen a significant increase in the number of singleplex and multiplex molecular assays for the detection of many of the organisms responsible for HAI, but more is needed as infections caused by organisms like Legionella pneumophila and Aspergillus species are still diagnosed with methods that have relatively low yield and are slow to provide actionable results. Finally, the use of novel techniques for outbreak investigations will provide new information on transmission of infectious agents in healthcare settings and allow stronger, evidence-based recommendations to be developed for prevention of HAIs in the immunocompromised host.

High-touch surfaces: microbial neighbours at hand

Despite considerable efforts, healthcare-associated infections (HAIs) continue to be globally responsible for serious morbidity, increased costs and prolonged length of stay. Among potentially preventable sources of microbial pathogens causing HAIs, patient care items and environmental surfaces frequently touched play an important role in the chain of transmission. Microorganisms contaminating such high-touch surfaces include Gram-positive and Gram-negative bacteria, viruses, yeasts and parasites, with improved cleaning and disinfection effectively decreasing the rate of HAIs. Manual and automated surface cleaning strategies used in the control of infectious outbreaks are discussed and current trends concerning the prevention of contamination by the use of antimicrobial surfaces are taken into consideration in this manuscript.