Role of the environment in the transmission of Clostridium difficile in health care facilities

Immune-based treatment and prevention of Clostridium difficile infection

Clostridium difficile (C. difficile) causes over 500,000 infections per year in the US, with an estimated 15,000 deaths and an estimated cost of $1-3 billion. Moreover, a continual rise in the incidence of severe C. difficile infection (CDI) has been observed worldwide. Currently, standard treatment for CDI is the administration of antibiotics. While effective, these treatments do not prevent and may contribute to a disease recurrence rate of 15-35%. Prevention of recurrence is one of the most challenging aspects in the field. A better knowledge of the molecular mechanisms of the disease, the host immune response and identification of key virulence factors of C. difficilenow permits the development of immune-based therapies. Antibodies specific for C. difficile toxins have been shown to effectively treat CDI and prevent disease relapse in animal models and in humans. Vaccination has been recognized as the most cost-effective treatment/prevention for CDI. This review will summarize CDI transmission, epidemiology, major virulent factors and highlights the rational and the development of immune-based approaches against this remerging threat.

Antimicrobial surfaces to prevent healthcare-associated infections: a systematic review

Contamination of the healthcare environment with pathogenic organisms contributes to the burden of healthcare-associated infection (HCAI). Antimicrobial surfaces are designed to reduce microbial contamination of healthcare surfaces. We aimed to determine whether antimicrobial surfaces prevent HCAI, transmission of antibiotic-resistant organisms (AROs), or microbial contamination, we conducted a systematic review of the use of antimicrobial surfaces in patient rooms. Outcomes included HCAI, ARO, and quantitative microbial contamination. Relevant databases were searched. Abstract review, full text review, and data abstraction were performed in duplicate. Risk of bias was assessed using the Cochrane Effective Practice and Organization Care (EPOC) Group risk of bias assessment tool and the strength of evidence determined using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Eleven studies assessed the effect of copper (N = 7), silver (N = 1), metal-alloy (N = 1), or organosilane-treated surfaces (N = 2) on microbial contamination. Copper surfaces demonstrated a median (range) reduction of microbial contamination of <1 log10 (<1 to 2 log10). Two studies addressed HCAI/ARO incidence. An RCT of copper surfaces in an ICU demonstrated 58% reduction in HCAI (P = 0.013) and 64% reduction in ARO transmission (P = 0.063) but was considered low-quality evidence due to improper randomization and incomplete blinding. An uncontrolled before-after study evaluating copper-impregnated textiles in a long-term care ward demonstrated 24% reduction in HCAI but was considered very-low-quality evidence based on the study design. Copper surfaces used in clinical settings result in modest reductions in microbial contamination. One study of copper surfaces and one of copper textiles demonstrated reduction in HCAI, but both were at high risk of bias.

Longitudinal trends in all healthcare-associated infections through comprehensive hospital-wide surveillance and infection control measures over the past 12 years: substantial burden of healthcare-associated infections outside of intensive care units and "other" types of infection

OBJECTIVE

Targeted surveillance has focused on device-associated infections and surgical site infections (SSIs) and is often limited to healthcare-associated infections (HAIs) in high-risk areas. Longitudinal trends in all HAIs, including other types of HAIs, and HAIs outside of intensive care units (ICUs) remain unclear. We examined the incidences of all HAIs using comprehensive hospital-wide surveillance over a 12-year period (2001-2012).

METHODS

This retrospective observational study was conducted at the University of North Carolina (UNC) Hospitals, a tertiary care academic facility. All HAIs, including 5 major infections with 14 specific infection sites as defined using CDC criteria, were ascertained through comprehensive hospital-wide surveillance. Generalized linear models were used to examine the incidence rate difference by infection type over time.

RESULTS

A total of 16,579 HAIs included 6,397 cases in ICUs and 10,182 cases outside ICUs. The incidence of overall HAIs decreased significantly hospital-wide (-3.4 infections per 1,000 patient days), in ICUs (-8.4 infections per 1,000 patient days), and in non-ICU settings (-1.9 infections per 1,000 patient days). The incidences of bloodstream infection, urinary tract infection, and pneumonia in hospital-wide settings decreased significantly, but the incidences of SSI and lower respiratory tract infection remained unchanged. The incidence of Clostridium difficile infection (CDI) increased remarkably. The outcomes were estimated to include 700 overall HAIs prevented, 40 lives saved, and cost savings in excess of $10 million.

CONCLUSIONS

We demonstrated success in reducing overall HAIs over a 12-year period. Our data underscore the necessity for surveillance and infection prevention interventions outside of the ICUs, for non-device-associated HAIs, and for CDI.

Cleaning and disinfecting environmental surfaces in health care: Toward an integrated framework for infection and occupational illness prevention

BACKGROUND

The Cleaning and Disinfecting in Healthcare Working Group of the National Institute for Occupational Safety and Health, National Occupational Research Agenda, is a collaboration of infection prevention and occupational health researchers and practitioners with the objective of providing a more integrated approach to effective environmental surface cleaning and disinfection (C&D) while protecting the respiratory health of health care personnel.

METHODS

The Working Group, comprised of >40 members from 4 countries, reviewed current knowledge and identified knowledge gaps and future needs for research and practice.

RESULTS

An integrated framework was developed to guide more comprehensive efforts to minimize harmful C&D exposures without reducing the effectiveness of infection prevention. Gaps in basic knowledge and practice that are barriers to an integrated approach were grouped in 2 broad areas related to the need for improved understanding of the (1) effectiveness of environmental surface C&D to reduce the incidence of infectious diseases and colonization in health care workers and patients and (2) adverse health impacts of C&D on health care workers and patients. Specific needs identified within each area relate to basic knowledge, improved selection and use of products and practices, effective hazard communication and training, and safer alternatives.

CONCLUSION

A more integrated approach can support multidisciplinary teams with the capacity to maximize effective and safe C&D in health care.

Non-inferiority of pulsed xenon UV light versus bleach for reducing environmental Clostridium difficile contamination on high-touch surfaces in Clostridium difficile infection isolation rooms

The standard for Clostridium difficile surface decontamination is bleach solution at a concentration of 10 % of sodium hypochlorite. Pulsed xenon UV light (PX-UV) is a means of quickly producing germicidal UV that has been shown to be effective in reducing environmental contamination by C. difficile spores. The purpose of this study was to investigate whether PX-UV was equivalent to bleach for decontamination of surfaces in C. difficile infection isolation rooms. High-touch surfaces in rooms previously occupied by C. difficile infected patients were sampled after discharge but before and after cleaning using either bleach or non-bleach cleaning followed by 15 min of PX-UV treatment. A total of 298 samples were collected by using a moistened wipe specifically designed for the removal of spores. Prior to disinfection, the mean contamination level was 2.39 c.f.u. for bleach rooms and 22.97 for UV rooms. After disinfection, the mean level of contamination for bleach was 0.71 c.f.u. (P = 0.1380), and 1.19 c.f.u. (P = 0.0017) for PX-UV disinfected rooms. The difference in final contamination levels between the two cleaning protocols was not significantly different (P = 0.9838). PX-UV disinfection appears to be at least equivalent to bleach in the ability to decrease environmental contamination with C. difficile spores. Larger studies are needed to validate this conclusion.

Clostridium difficile infection in the elderly

Clostridium difficile-associated illness is an increasingly prevalent and morbid condition. The elderly population is at a disproportionate risk of developing symptomatic disease and associated complications, including progression to severe or fulminant disease, and development of recurrent infections. This article analyzes the factors that influence C difficile disease propensity and severity, with particular attention directed toward features relevant to the rapidly aging population.

Assessing control bundles for Clostridium difficile: a review and mathematical model

Clostridium difficile is the leading cause of infectious diarrhea in hospitalized patients. Integrating several infection control and prevention methods is a burgeoning strategy for reducing disease incidence in healthcare settings. We present an up-to-date review of the literature on ‘control bundles' used to mitigate the transmission of this pathogen. All clinical studies of control bundles reported substantial reductions in disease rates, in the order of 33%–61%. Using a biologically realistic mathematical model we then simulated the efficacy of different combinations of the most prominent control methods: stricter antimicrobial stewardship; the administering of probiotics/intestinal microbiota transplantation; and improved hygiene and sanitation. We also assessed the health gains that can be expected from reducing the average length of stay of inpatients. In terms of reducing the rates of colonization, all combinations had the potential to give rise to marked improvements. For example, halving the number of inpatients on broad-spectrum antimicrobials combined with prescribing probiotics or intestinal microbiota transplantation could cut pathogen carriage by two-thirds. However, in terms of symptomatic disease incidence reduction, antimicrobials, probiotics and intestinal microbiota transplantation proved substantially less effective. Eliminating within-ward transmission by improving sanitation and reducing average length of stay (from six to three days) yielded the most potent symptomatic infection control combination, cutting rates down from three to less than one per 1000 hospital bed days. Both the empirical and theoretical exploration of C. difficile control combinations presented in the current study highlights the potential gains that can be achieved through strategically integrated infection control.

Environmental cleaning resources and activities in Canadian acute care hospitals

BACKGROUND

Environmental cleaning interventions have increased cleaning effectiveness and reduced antibiotic-resistant organisms in hospitals. This study examined cleaning in Canadian acute care hospitals with the goal of developing strategies to improve cleaning and reduce antibiotic-resistant organism rates.

METHODS

Managers most responsible for environmental services (EVS) completed an extensive online survey that assessed EVS resources and cleaning practices.

RESULTS

The response rate was 50.5%; 96 surveys were completed, representing 103 of 204 hospitals. Whereas 86.3% (82/95) of managers responsible for EVS reported their staff was adequately trained and 76.0% (73/96) that supplies and equipment budgets were sufficient, only 46.9% (45/96) reported that EVS had enough personnel to satisfactorily clean their hospital. A substantial minority (36.8%, 35/95) of EVS departments did not audit the cleaning of medical surgical patient rooms on at least a monthly basis. Cleaning audits of medical surgical patient rooms frequently included environmental marking methods in only one third (33.3%, 31/93) of hospitals and frequently included the measurement of residual bioburden in only 13.8% (13/94).

CONCLUSION

There was a general need for increased and improved auditing of environmental cleaning in Canadian hospitals, and there were perceived EVS staffing deficits in the majority of hospitals.

Working relationships of infection prevention and control programs and environmental services and associations with antibiotic-resistant organisms in Canadian acute care hospitals

BACKGROUND

Environmental contamination in hospitals with antibiotic-resistant organisms (AROs) is associated with patient contraction of AROs. This study examined the working relationship of Infection Prevention and Control (IPAC) and Environmental Services and the impact of that relationship on ARO rates.

METHODS

Lead infection control professionals completed an online survey that assessed the IPAC and Environmental Services working relationship in their acute care hospital in 2011. The survey assessed cleaning collaborations, staff training, hospital cleanliness, and nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection, vancomycin-resistant Enterococcus (VRE) infection, and Clostridium difficile infection (CDI).

RESULTS

The survey was completed by 58.3% of hospitals (119 of 204). Two-thirds (65.8%; 77 of 117) of the respondents reported that their cleaners were adequately trained, and 62.4% (73 of 117) reported that their hospital was sufficiently clean. Greater cooperation between IPAC and Environmental Services was associated with lower rates of MRSA infection (r = -0.22; P = .02), and frequent collaboration regarding cleaning protocols was associated with lower rates of VRE infection (r = -0.20; P = .03) and CDI (r = -0.31; P < .001).

CONCLUSIONS

Canadian IPAC programs generally had collaborative working relationships with Environmental Services, and this was associated with lower rates of ARO. Deficits in the adequacy of cleaning staff training and hospital cleanliness were identified. The promotion of collaborative working relationships and additional training for Environmental Services workers would be expected to lower ARO rates.

Investigation of potentially pathogenic Clostridium difficile contamination in household environs

As Clostridium difficile spores are resistant to many household cleaning products, the potential for community household contamination is high. The purpose of this study was to assess the prevalence of toxigenic C. difficile from environmental sources from a large urban area. Three to 5 household items or environmental dust was collected from 30 houses in Houston, Texas. A total of 127 environmental samples were collected from shoe bottoms (n = 63), bathroom surfaces (n = 15), house floor dusts (n = 12), or other household surfaces (n = 37). Forty one of 127 samples (32.3%) grew C. difficile. All 41 isolates were positive for toxin A and B genes and no isolate was positive for binary toxin genes. Shoe bottom swab samples had the highest percent of positive samples (25/63; 39.7%) followed by bathroom/toilet surfaces (5/15; 33.3%), house floor dust (4/12; 33.3%), and other surface swabs (7/37; 18.9%). Strains were grouped into 25 different ribotypes, the most prevalent type was 001 (5 strains). In conclusion, a high rate of environmental contamination of C. difficile was observed from community households from a large urban area.