Infection control and antimicrobial restriction practices for antimicrobial-resistant organisms in Canadian tertiary care hospitals

Vaccination, time lost from work, and COVID-19 infections: a Canadian healthcare worker retrospective cohort study

The COVID-19 pandemic highlighted hurdles for healthcare delivery and personnel globally. Vaccination has been an important tool for preventing severe illness and death in healthcare workers (HCWs) as well as the public at large. However, vaccination has resulted in some HCWs requiring time off work post-vaccination to recover from adverse events. We aimed to understand which HCWs needed to take time off work post-vaccination, for which vaccine types and sequence, and how post-vaccination absence impacted uptake of booster doses in a cohort of 26,267 Canadian HCWs. By March 31, 2022, more than 98% had received at least two doses of the approved COVID-19 vaccines, following a two-dose mandate. We found that recent vaccination and longer intervals between doses were associated with significantly higher odds of time-loss, whereas being a medical resident and receiving the BNT162b2 vaccine were associated with lower odds. A history of lab-confirmed SARS-CoV-2 infection was associated with lower odds of receiving a booster dose compared with no documented infection, aOR 0.61 (95% CI: 0.55, 0.68). Similarly, taking sick time following the first or second dose was associated with lower odds of receiving a booster dose, aOR 0.83 (95% CI: 0.75, 0.90). As SARS-CoV-2 becomes endemic, the number and timing of additional doses for HCWs requires consideration of prevention of illness as well as service disruption from post-vaccination time-loss. Care should be taken to ensure adequate staffing if many HCWs are being vaccinated, especially for coverage for those who are more likely to need time off to recover.

Effects of the proportion of high-risk patients and control strategies on the prevalence of methicillin-resistant Staphylococcus aureus in an intensive care unit

Background

The presence of nosocomial pathogens in many intensive care units poses a threat to patients and public health worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen endemic in many hospital settings. Patients who are colonized with MRSA may develop an infection that can complicate their prior illness.

Methods

A mathematical model to describe transmission dynamics of MRSA among high-risk and low-risk patients in an intensive care unit (ICU) via hands of health care workers is developed. We aim to explore the effects of the proportion of high-risk patients, the admission proportions of colonized and infected patients, the probability of developing an MRSA infection, and control strategies on MRSA prevalence among patients.

Results

The increasing proportion of colonized and infected patients at admission, along with the higher proportion of high-risk patients in an ICU, may significantly increase MRSA prevalence. In addition, the prevalence becomes higher if patients in the high-risk group are more likely to develop an MRSA infection. Our results also suggest that additional infection prevention and control measures targeting high-risk patients may considerably help reduce MRSA prevalence as compared to those targeting low-risk patients.

Conclusions

The proportion of high-risk patients and the proportion of colonized and infected patients in the high-risk group at admission may play an important role on MRSA prevalence. Control strategies targeting high-risk patients may help reduce MRSA prevalence.

Incidence of bacteremia and antimicrobial resistance, and associated factors among patients transferred from long-term care hospital

OBJECTIVE

To evaluate the prevalence of bacteremia and antimicrobial resistance, and associated factors among infectious patients transferred from long-term care hospitals (LTCHs).

METHODS

Consecutive adult patients who were transferred for suspected infection from affiliated LTCH's to study hospital emergency department (ED) over a 12 month period from January to December 2016 were included retrospectively. Patients with positive blood cultures (excluding contaminants as clinically determined) were defined as primary measure and subjected to further analysis according to antimicrobial resistance pattern. The latter was categorized into 4 subgroups based on groups of antimicrobial choices for empiric choices of suspected bloodstream infections. R-Group 0: bacteria susceptible to penicillin and amoxicillin; R-Group 1: bacteria resistant to penicillin/amoxicillin, first, second, or third generation cephalosporins. R-Group 2: ESBL-producing bacteria or bacteria resistant methicillin, fourth generation cephalosporin, or fluoroquinolone. R-Group 3: highly resistant pathogens including vancomycin resistant enterococci, carbapenem or colistin resistant Gram negatives. Blood culture isolate could therefore be included in >1 group.

RESULTS

Among 756 patients who were transferred from LTCHs, we excluded 278 patients who were not suspicious of infection and 65 patients who were not checked blood culture at ED. In total, 422 patients were enrolled. The incidence of bacteremia was 20.4% (n = 86). The most frequent pathogen was E. coli (n = 25) followed by S. aureus (n = 10), S. epidermidis (n = 8), and K. pneumonia (n = 6). The incidences of the R-Group 1, 2, and 3 groups were 16.8% (n = 71), 14.4% (n = 61), and 1.4% (n = 6), respectively. Of the Gram-positive pathogens (n = 44), the R-Group 1, 2, and 3 groups were 84.1% (n = 37), 75.0% (n = 33), and 9.1% (n = 4), respectively. Of the Gram-negative pathogens (n = 46), the R-Group 1, 2, and 3 groups were 82.6% (n = 38), 69.6% (n = 32), and 4.3% (n = 2), respectively. Among tested variables, initial serum procalcitonin level was significantly associated with the presence of bacteremia (AOR 1.03, 95% confidence interval 1.00-1.05), R-Group 1 (1.04, 1.01-1.07) and the R-Group 2 (1.04, 1.00-1.06).

CONCLUSIONS

The prevalence of bloodstream infections in patients admitted from LTCH was high (20.4%) with majority of these infections from resistant bacteria. Procalcitonin levels were significantly higher in bacteremic patients with an increasing trend towards bacteria in the antimicrobial resistant groups.

Optometric infection control guidelines assessing patients with methicillin-resistant Staphylococcus aureus

The purpose of this scoping review was to present the state of research regarding optometric infection control guidelines for the assessment of patients with methicillin-resistant Staphylococcus aureus (MRSA) and to identify any areas requiring further research. Twelve articles were carefully chosen for review. Data extracted included information regarding appropriate handwashing methods (five articles), indications for use of personal protective equipment (one article), management of surfaces that come in contact with an MRSA-infected person (three articles), recommendations for patient appointment scheduling/seating (three articles) and suggestions for staff training (three articles). The results of the review demonstrated that there exist many gaps in the literature regarding comprehensive optometric-specific infection control guidelines. Further research regarding appropriate handwashing methods, equipment disinfection techniques, extent and breadth of staff training and indications for use of personal protective equipment is required to better understand what precautions must be taken in an optometric setting when encountering patients with MRSA.

Prevention and Control of Multidrug-Resistant Gram-Negative Bacteria in Adult Intensive Care Units: A Systematic Review and Network Meta-analysis

Background

This study evaluated the relative efficacy of strategies for the prevention of multidrug-resistant gram-negative bacteria (MDR-GNB) in adult intensive care units (ICUs).

Methods

A systematic review and network meta-analysis was performed; searches of the Cochrane Library, PubMed, Embase, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) included all randomized controlled trials and observational studies conducted in adult patients hospitalized in ICUs and evaluating standard care (STD), antimicrobial stewardship program (ASP), environmental cleaning (ENV), decolonization methods (DCL), or source control (SCT), simultaneously. The primary outcomes were MDR-GNB acquisition, colonization, and infection; secondary outcome was ICU mortality.

Results

Of 3805 publications retrieved, 42 met inclusion criteria (5 randomized controlled trials and 37 observational studies), involving 62068 patients (median age, 58.8 years; median APACHE [Acute Physiology and Chronic Health Evaluation] II score, 18.9). The majority of studies reported extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and MDR Acinetobacter baumannii. Compared with STD, a 4-component strategy composed of STD, ASP, ENV, and SCT was the most effective intervention (rate ratio [RR], 0.05 [95% confidence interval {CI}, .01-.38]). When ENV was added to STD+ASP or SCT was added to STD+ENV, there was a significant reduction in the acquisition of MDR A. baumannii (RR, 0.28 [95% CI, .18-.43] and 0.48 [95% CI, .35-.66], respectively). Strategies with ASP as a core component showed a statistically significant reduction the acquisition of ESBL-producing Enterobacteriaceae (RR, 0.28 [95% CI, .11-.69] for STD+ASP+ENV and 0.23 [95% CI, .07-.80] for STD+ASP+DCL).

Conclusions

A 4-component strategy was the most effective intervention to prevent MDR-GNB acquisition. As some strategies were differential for certain bacteria, our study highlighted the need for further evaluation of the most effective prevention strategies.

Controlling the spread of vancomycin-resistant enterococci. Is active screening worthwhile?

Vancomycin-resistant enterococci (VRE) are significant causes of healthcare-acquired infections. Active screening, i.e. the use of rectal swabs or faeces to detect carriage in at-risk patients, has been described as contributing to prevention by identifying previously unrecognized cases. The aim of this review was to determine the impact of screening for VRE on prevention and control, its cost-effectiveness and recent approaches to laboratory detection. A review of published studies in English from 2000 was undertaken. Whereas various guidelines were accessed and reviewed, the emphasis was on original reports and studies. It was determined that the patient groups who may need screening are those admitted to critical care units, haematology/oncology and transplant wards, patients on chronic dialysis and patients admitted to acute hospitals from long-stay units. Active screening is associated with reduced VRE colonization and infection and cost savings in some studies, even if these fall short of randomized trials. Selective media increase sensitivity and reduce the time to detection but the role of molecular methods remains to be determined. In conclusion, active screening contributes to VRE prevention probably by heightening awareness of control measures, including isolation. However, further studies are required to: better define high-risk groups that warrant screening; quantify the clinical and economic benefit; and determine the optimal laboratory methods in a range of different patient populations.

Access to antibiotics: a safety and equity challenge for the next decade

Bacterial resistance to antibiotics is increasing worldwide in healthcare settings and in the community. Some microbial pathogens have become resistant to multiple antibiotics, if not all presently available, thus severely compromising treatment success and contributing to enhanced morbidity, mortality, and resource use. The major driver of resistance is misuse of antibiotics in both human and non-human medicine. Both enhanced access and restricted use in many parts of the world is mandatory. There is an urgent need for an international, integrated, multi-level action to preserve antibiotics in the armamentarium of the 21st century and address the global issue of antimicrobial resistance.

Disparity in infection control practices for multidrug-resistant Enterobacteriaceae

BACKGROUND

There is a lack of empiric evidence regarding the optimal approach to controlling the transmission of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) and carbapenem-resistant Enterobacteriaceae (CRE). In this context, we expect that infection control practices for these organisms vary widely between hospitals.

METHODS

A survey examining infection control practices for ESBL-E and CRE was distributed to 6 academic and 9 community hospitals in Toronto, Canada.

RESULTS

All hospitals responded to the survey. Among 15 hospitals in 1 geographic area, 8 different approaches to the management of ESBL-E were utilized. There was wide variation in the use infection control practices including admission screening (53% and 53%), contact precautions (53% and 100%), and isolation (60% and 100%) for ESBL-E and CRE, respectively. Of hospitals performing admission screening, 75% used risk factor-based screening for ESBL-E and CRE.

CONCLUSION

Even within a single geographic area, there is wide variation in infection control strategies to contain or control ESBL-E and CRE. These results are concerning given evidence that a coordinated approach may be required to prevent or limit the emergence of CRE.

Methicillin-resistant Staphylococcus aureus colonization or infection in Canada: National Surveillance and Changing Epidemiology, 1995-2007

OBJECTIVE

To determine the incidence and describe the changing epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection in Canadian hospitals from 1995-2007.

SETTING

Forty-eight hospitals participating in the Canadian Nosocomial Infection Surveillance Program.

DESIGN

Prospective, laboratory-based surveillance for incident cases of MRSA colonization or infection among hospitalized patients.

METHODS

Clinical and epidemiologic data were obtained by review of hospital records. Standard criteria were used to determine whether MRSA colonization or infection was present and whether the MRSA strain was healthcare associated or community associated. A representative subset of isolates was characterized by use of pulsed-field gel electrophoresis and staphylococcal cassette chromosome (SCC) mec typing.

RESULTS

From 1995 to 2007, a total of 37,169 hospitalized patients were newly identified as either infected or colonized with MRSA, and the overall incidence of both MRSA colonization and MRSA infection increased from 0.65 to 11.04 cases per 10,000 patient-days (P < .001). Of these 37,169 patients, 11,828 (32%) had an MRSA infection, and infection rate increased from 0.36 to 3.43 cases per 10,000 patient-days. The proportion of community-associated MRSA strains increased from 6% to 23% (P < .001). The most common genotype (47% of isolates) was CMRSA-2 (USA100/800); in 2007, CMRSA-10 (USA300) was the second most common strain (27% of isolates), associated with SCCmec type IV. Patients with CMRSA-10 were predominantly from western Canada and were more likely to be children (odds ratio [OR], 10.0 [95% confidence interval {CI}, 7.4-13.4]) and to have infection (OR, 2.3 [95% CI, 1.9-2.7]), especially skin and/or soft tissue infection (OR, 5.9 [95% CI, 5.0-6.9]).

CONCLUSIONS

The overall incidence of both MRSA colonization and MRSA infection increased 17-fold in Canadian hospitals from 1995 to 2007. There has also been a dramatic increase in cases of community-associated MRSA infection due to the CMRSA-10 (USA300) clone. Continued surveillance is needed to monitor the ongoing evolution of MRSA colonization or infection in Canada and globally.

Methicillin-resistant Staphylococcus aureus in Canada: a historical perspective and lessons learned

The history of methicillin-resistant Staphylococcus aureus (MRSA) in Canada has many similarities to MRSA evolution worldwide, but especially to that in the United States and United Kingdom. Reports of MRSA occurred as early as 1964, and community isolates were cited in the 1970s. Nosocomial outbreaks were becoming common by 1978 and flourished gradually thereafter. Endemic institutional MRSA became predominant in the 1990s, threatening large teaching hospitals in particular. In the last decade, both hospital-acquired and community-acquired MRSA have created major medical problems in Canada. More recently, an epidemic of Canadian community-acquired MRSA-10, has led to heightened public health concerns. Canadian contributions to MRSA science are numerous, with organized surveillance continuing to mature across the nation. A typing system for epidemic clones is now available and is being judiciously applied. Estimated costs for MRSA surveillance, treatment, and control are extraordinary, paralleling the dramatic rise in the number of MRSA isolations. Whereas surveillance continues to form an essential aspect of MRSA management, control, eradication, and overall diminution, MRSA reservoirs deserve much greater attention. Such efforts, however, must be as widely publicized in the community and in patient homes as they are in medical institutions responsible for both acute and long-term care.

Do guidelines for the prevention and control of methicillin-resistant Staphylococcus aureus make a difference?

Many countries have national guidelines for the prevention and control of methicillin-resistant Staphylococcus aureus (MRSA) that are similar in approach. The evidence base for many recommendations is variable, and often, in the drafting of such guidelines, the evidence is either not analysed or not specifically reviewed. Guidelines usually recommend screening and early detection, hand hygiene, patient isolation or cohorting, and decolonization. Although many components of a prevention and control programme appear to be self-evident, e.g. patient isolation, the scientific base underpinning these is poor, and scientifically rigorous studies are required. Nonetheless, where measures, based on what evidence there is and on common sense, are implemented, and where the necessary resources are provided, MRSA can be controlled. In The Netherlands and in other low-prevalence countries, these measures have largely kept healthcare facilities MRSA-free. In MRSA-endemic countries, such as Spain and Ireland, national guidelines are often not fully implemented, owing to apparently inadequate resources or a lack of will. However, recent studies from France and Australia demonstrate what is possible in high-prevalence countries when best practice is effectively implemented, with potentially major benefits for patients, the respective health services, and society.

Detection and characterization of heterogeneous vancomycin-intermediate Staphylococcus aureus isolates in Canada: results from the Canadian Nosocomial Infection Surveillance Program, 1995-2006

We describe the epidemiology of heterogeneously resistant Staphylococcus aureus (hVISA) identified in Canadian hospitals between 1995 and 2006. hVISA isolates were confirmed by the population analysis profiling-area under the curve method. Only 25 hVISA isolates (1.3% of all isolates) were detected. hVISA isolates were more likely to have been health care associated (odds ratio [OR], 5.1; 95% confidence interval [CI], 1.9 to 14.2) and to have been recovered from patients hospitalized in central Canada (OR, 3.0; 95% CI, 1.2 to 7.4). There has been no evidence of vancomycin "MIC creep" in Canadian strains of methicillin (meticillin)-resistant S. aureus, and hVISA strains are currently uncommon.

Vancomycin-resistant enterococci in Canada: results from the Canadian nosocomial infection surveillance program, 1999-2005

Surveillance for vancomycin-resistant enterococci (VRE) in sentinel Canadian hospitals has been conducted since 1999. From 1999 to 2005, the rate of VRE detection increased from 0.37 to 1.32 cases per 1,000 patients admitted, and the rate of VRE infection increased from 0.02 to 0.05 cases per 1,000 patients admitted. Thirty-three percent of all patients with VRE detected that were reported during 1999-2005 were identified in 2005, with increases seen in all regions of Canada. Although the incidence rate of VRE carriage in Canada is increasing, it remains very low.