Investigation of a severe SARS-CoV-2 outbreak in a long-term care home early in the pandemic.

BACKGROUND: The implementation of outbreak management measures has decreased the frequency and severity of SARS-CoV-2 outbreaks in Ontario long-term care homes. We describe the epidemiological and laboratory data from one of the first such outbreaks in Ontario to assess factors associated with its severity, and the impact of progressive interventions for infection control over the course of the outbreak. METHODS: We obtained line list and outbreak data from the public health unit to describe resident and staff cases, severity and distribution of cases over time and within the outbreak facility. Where available, we obtained data on laboratory specimens from the Public Health Ontario Laboratory and performed whole genome sequencing and phylogenetic analysis of viral specimens from the outbreak. RESULTS: Among 65 residents of the long-term care home, 61 (94%) contracted SARS-CoV-2, with a case fatality rate of 45% (28/61). Among 67 initial staff, 34 (51%) contracted the virus and none died. When the outbreak was declared, 12 staff, 2 visitors and 9 residents had symptoms. Resident cases were located in 3 of 4 areas of the home. Phylogenetic analysis showed tight clustering of cases, with only 1 additional strain of genetically distinct SARS-CoV-2 identified from a staff case in the third week of the outbreak. No cases were identified among 26 new staff brought into the home after full outbreak measures were implemented. INTERPRETATION: Rapid and undetected viral spread in a long-term care home led to high rates of infection among residents and staff. Progressive implementation of outbreak measures after the peak of cases prevented subsequent staff cases and are now part of long-term care outbreak policy in Ontario.

Enquête sur une éclosion importante de SRAS-CoV-2 dans un établissement de soins de longue durée au début de la pandémie.

CONTEXTE: Le déploiement de mesures de gestion des éclosions de SRAS-CoV-2 dans les établissements de soins de longue durée en Ontario a permis d'en réduire la fréquence et la gravité. Nous décrivons ici les données épidémiologiques et de laboratoire d'une de ces premières éclosions en Ontario afin de déterminer les facteurs associés à son importance et les impacts des interventions progressives de lutte contre les infections appliquées pendant la durée de l'éclosion. MÉTHODES: Nous avons obtenu du bureau de santé la liste des cas et les données de l'éclosion afin de décrire les cas chez les résidents et le personnel, leur gravité et leur distribution dans le temps et à l'intérieur de l'établissement touché. Quand elles étaient disponibles, nous avons obtenu des données concernant les échantillons soumis au laboratoire de Santé publique Ontario et effectué un séquençage complet et une analyse phylogénétique des échantillons viraux de l'éclosion. RÉSULTATS: Sur les 65 résidents de l'établissement de soins de longue durée, 61 (94 %) ont contracté le SRAS-CoV-2, le taux de létalité étant de 45 % (28/61). Parmi les 67 employés initiaux, 34 (51 %) ont contracté le virus, et aucun n'est décédé. Lorsque l'éclosion a été déclarée, 12 employés, 2 visiteurs et 9 résidents présentaient des symptômes. Parmi les résidents, les cas se trouvaient dans 3 des 4 secteurs de l'établissement. L'analyse phylogénétique a montré une forte similitude des séquences; une seule autre souche de SRAS-CoV-2 génétiquement distincte a été identifiée chez un employé à la troisième semaine de l'éclosion. Après le déploiement de toutes les mesures de gestion de l'éclosion, aucun cas n'a été identifié parmi les 26 nouveaux employés appelés en renfort. INTERPRÉTATION: La propagation rapide et non détectée du virus dans un établissement de soins de longue durée a donné lieu à des taux élevés d'infection chez les résidents et le personnel. L'application progressive de mesures de gestion après le pic de l'éclosion a permis d'éviter la contamination du personnel appelé en renfort et fait désormais partie des politiques à long terme de prévention des éclosions en Ontario.

Long-term care certification in infection prevention: The time is now!

The complexity and risks of long-term care (LTC) resident care has continued to increase, including infection risk, as regulatory agencies and the LTC industry seek credible and knowledgeable infection preventionists for their facilities. Developing an LTC infection prevention and control certification exam indicates infection preventionists can proficiently manage infection prevention and control programs.

Reducing the risk of severe complications among patients with Clostridium difficile infection.

BACKGROUND: The incidence and severity of Clostridium difficile infections are increasing, and there is a need to optimize the prevention of complicated disease. OBJECTIVE: To identify modifiable processes of care associated with an altered risk of C difficile complications. METHODS: A retrospective cohort study (with prospective case ascertainment) of all C difficile infections during 2007/2008 at a tertiary care hospital was conducted. RESULTS: Severe complications were frequent (occurring in 97 of 365 [27%] C difficile episodes), with rapid onset (median three days postdiagnosis). On multivariable analysis, nonmodifiable predictors of complications included repeat infection (OR 2.67), confusion (OR 2.01), hypotension (OR 0.97 per increased mmHg) and elevated white blood cell count (OR 1.04 per 109 cells/L). Protection from complications was associated with initial use of vancomycin (OR 0.24); harm was associated with ongoing use of exacerbating antibiotics (OR 3.02). CONCLUSION: C difficile infections often occur early in the disease course and are associated with high complication rates. Clinical factors that predicted a higher risk of complications included confusion, hypotension and leukocytosis. The most effective ways to improve outcomes for patients with C difficile colitis are consideration of vancomycin as first-line treatment for moderate to severe cases, and the avoidance of unnecessary antibiotics.

Beyond flu: Trends in respiratory infection outbreaks in Ontario healthcare settings from 2007 to 2017, and implications for non-influenza outbreak management.

BACKGROUND: Outbreaks cause significant morbidity and mortality in healthcare settings. Current testing methods can identify specific viral respiratory pathogens, yet the approach to outbreak management remains general. OBJECTIVES: Our aim was to examine pathogen-specific trends in respiratory outbreaks, including how attack rates, case fatality rates and outbreak duration differ by pathogen between hospitals and long-term care (LTC) and retirement homes (RH) in Ontario. METHODS: Confirmed respiratory outbreaks in Ontario hospitals and LTC/RH reported between September 1, 2007, and August 31, 2017, were extracted from the integrated Public Health Information System (iPHIS). Median attack rates and outbreak duration and overall case fatality rates of pathogen-specific outbreaks were compared in both settings. RESULTS: Over the 10-year surveillance period, 9,870 confirmed respiratory outbreaks were reported in Ontario hospitals and LTC/RH. Influenza was responsible for most outbreaks (32% in LTC/RH, 51% in hospitals), but these outbreaks were shorter and had lower attack rates than most non-influenza outbreaks in either setting. Human metapneumovirus, while uncommon (<4% of outbreaks) had high case fatality rates in both settings. CONCLUSION: Attack rates and case fatality rates varied by pathogen, as did outbreak duration. Development of specific outbreak management guidance that takes into account pathogen and healthcare setting may be useful to limit the burden of respiratory outbreaks.

Value of certification in infection prevention and control.

The Certification Board of Infection Control and Epidemiology conducted a marketing research study to determine the perceived value of the certification in infection prevention and control among infection prevention professionals and other stakeholders. Four thematic categories were identified: certification process and standards; professionalism, competency, and career growth; patient care, safety, infection prevention and control; and regulatory compliance. Respondents stated that certification demonstrated professional competency, increased career growth, improved regulatory compliance, was important in influencing legislation, and improved the practice of infection prevention and control. Opportunities were to reevaluate eligibility criteria and examination difficulty; demonstrate how certification increases financial compensation and organizational recognition; and offer recertification through continuing education based on the study findings, strategic recommendations and next steps were incorporated into the strategic plan. This article is an overview and summarizes the study findings.

Acquisition of methicillin-resistant Staphylococcus aureus (MRSA) in contacts of patients newly identified as colonized or infected with MRSA in the immediate postexposure and postdischarge periods.

The acquisition of methicillin-resistant Staphylococcus aureus (MRSA) after exposure to patients colonized or infected with MRSA was assessed. Among contacts with complete surveillance screening, the rate of acquisition was 5.7% and was lower in those identified postdischarge (17/683, 2.5%) compared with those tested in the immediate postexposure period (62/706, 8.8%).

Do physicians clean their hands? Insights from a covert observational study.

Physicians are notorious for poor hand hygiene (HH) compliance. We wondered if lower performance by physicians compared with other health professionals might reflect differences in the Hawthorne effect. We introduced covert HH observers to see if performance differences between physicians and nurses decreased and to gain further insights into physician HH behaviors. Following training and validation with a hospital HH auditor, 2 students covertly measured HH during clinical rotations. Students rotated off clinical services every week to increase exposure to different providers and minimize risk of exposing the covert observation. We compared covertly measured HH compliance with data from overt observation by hospital auditors during the same time period. Covert observation produced much lower HH compliance than recorded by hospital auditors during the same time period: 50.0% (799/1597) versus 83.7% (2769/3309) (P < 0.0002). The difference in physician compliance between hospital auditors and covert observers was 19.0% (73.2% vs 54.2%); for nurses this difference was much higher at 40.7% (85.8% vs 45.1%) (P < 0.0001). Physician trainees showed markedly better compliance when attending staff cleaned their hands compared with encounters when attending did not (79.5% vs 18.9%; P < 0.0002). Our study suggests that traditional HH audits not only overstate HH performance overall, but can lead to inaccurate inferences about performance by professional groupings due to relative differences in the Hawthorne effect. We suggest that future improvement efforts will rely on more accurate HH monitoring systems and strong attending physician leadership to set an example for trainees. Journal of Hospital Medicine 2015;11:862-864. © 2015 Society of Hospital Medicine.

Indwelling urinary catheter surveillance using a Task-oriented nurse acuity system.

The task-oriented nurse acuity system (TONAS) has long been used to calculate nursing care needs on hospital patient units, and include nursing documentation on indwelling urinary catheter use. We performed a 2500-patient validation study of our organization's TONAS, which demonstrated high interrater reliability with manual audits (κ >0.92). For institutions that continue to rely on manual surveillance of urinary catheter use, a TONAS may represent a reliable method of automated surveillance.

Training costs and investment payback of implementing molecular diagnostics for identification of vancomycin resistant enterococci in a clinical microbiology laboratory.

Molecular diagnostics may be a more efficient method to manage resources; but most Microbiology laboratories have not introduced them into routine use due to the specialized training required. Using vancomycin resistant enterococci (VRE) screening during a comparison of a multiplex PCR (MPCR) and conventional biochemical testing (CBT) we studied 3 objectives: 1) to develop a molecular diagnostics in-house training program, 2) to assess the training program outcomes for competency and confidence, and 3) to determine laboratory payback. A training program for 14 technologists using multiple adult learning methods was implemented. Methods to minimize technical errors were introduced and included: use of a calibrated loop to deliver sample; prealiquotting reagents; increasing volume of specimen; addition of gel loading dye directly into reaction tubes; and establishment of an equivocal zone. In our laboratory MPCR costs $7.06 less than CBT, therefore the payback period for training and implementation would be approximately 3 years.

Risk factors for Staphylococcus aureus surgical site infection during an outbreak in patients undergoing cardiovascular surgery.

BACKGROUND: This study examined the epidemiology of an outbreak of Staphylococcus aureus surgical site infections (SSI) after cardiovascular surgery, and analyzed risk factors for S aureus SSIs. METHODS: This was a retrospective case-control study to determine risk factors for S aureus SSI in 38 patients who developed S aureus SSI during the outbreak period, compared with age-, sex-, and procedure-matched controls. S aureus strains were typed by pulsed-field gel electrophoresis. RESULTS: A total of 38 patients had S aureus SSI. Pulsed-field gel electrophoresis identified transmission of 3 S aureus clones (2 MSSA clones and 1 MRSA clone). Twenty-one health care workers were carriers of outbreak strains. In multivariate analysis, the significant risk factors for S aureus SSI were previous cardiac surgery (odds ratio, 7.41; 95% confidence interval, 1.05-52.16) and long procedure duration (odds ratio, 1.49; 95% confidence interval, 1.00-2.21). CONCLUSIONS: This outbreak demonstrates evidence of nosocomial transmission of 3 clones of S aureus in the setting of incomplete compliance with recommended standard perioperative infection control measures, associated with a high prevalence of staff carriage of the predominant outbreak strains.

Nosocomial transmission of New Delhi metallo-ß-lactamase-1-producing Klebsiella pneumoniae in Toronto, Canada.

DESIGN: An analysis of a cluster of New Delhi metallo-ß-lactamase-1-producing Klebsiella pneumoniae (NDM1-Kp) and a retrospective case-cohort analysis of risk factors for acquisition in contacts of NDM1-Kp-positive patients. SETTING: A 1,100-bed Canadian academic tertiary care center. PATIENTS: Two index patients positive for NDM1-Kp as well as 45 contacts (roommates, ward mates, or environmental contacts) were investigated. METHODS: Retrospective chart reviews of all patients colonized or infected with NDM1-Kp as well as contacts of these patients were performed in order to describe the epidemiology and impact of infection prevention and control measures. A case-cohort analysis was conducted investigating 45 contacts of NDM1-Kp-positive patients to determine risk factors for acquisition of NDM1-Kp. Rectal swabs were screened for NDM1-Kp using chromogenic agar. Presence of bla(NDM-1) was confirmed by multiplex polymerase chain reaction. Clonality was assessed with pulsed-field gel electrophoresis (PFGE) using restriction enzyme XbaI. RESULTS: Two index cases carrying NDM1-Kp with different PFGE patterns were identified. Nosocomial transmission to 7 patients (4 roommates, 2 ward mates, and 1 environmental contact) was subsequently identified. Risk factors for acquisition of NDM1-Kp were a history of prior receipt of certain antibiotics (fluoroquinolones [odds ratio (OR), 16.8 (95% confidence interval [CI], 1.30-58.8); [Formula: see text]], trimethoprim-sulfamethoxazole [OR, 11.3 (95% CI, 1.84-70.0); [Formula: see text]], and carbapenems [OR, 16.8 (95% CI, 1.79-157.3); [Formula: see text]]) and duration of exposure to NDM1-Kp-positive roommates (26.5 vs 6.7 days; [Formula: see text]). CONCLUSION: Two distinct clones of NDM1-Kp were transmitted to 7 inpatient contacts over several months. Implementation of contact precautions, screening of contacts for NDM1-Kp carriage, and attention to environmental disinfection contributed to the interruption of subsequent spread of the organism. The appropriate duration and frequency of screening contacts of NDM1-Kp-positive patients require further study.

Validation of administrative population-based data sets for the detection of cesarean delivery surgical site infection.

We validated population-based hospital, emergency room, and physician claim databases for the detection of surgical site infections against the reference standard of clinical surveillance. Although these data sets are highly specific and could be used to define research cohorts, their low sensitivity and positive predictive value make them inadequate for use as quality indicators.

The impact of treatment modality on infection-related hospitalization rates in peritoneal dialysis and hemodialysis patients.

BACKGROUND AND OBJECTIVES: Infection is a major cause of morbidity and mortality in the dialysis population. This study compares the rates of infection-related hospitalization (IRH) in incident chronic dialysis patients initiating outpatient peritoneal dialysis (PD) and hemodialysis (HD). METHODS AND PATIENTS: This was a retrospective cohort study at the dialysis program of a tertiary-care center in Toronto, Canada. Incident chronic dialysis patients that were eligible for both PD and HD and started outpatient dialysis between 1 January 2004 and 31 August 2008 were included. Dialysis modality was assigned at the start of outpatient dialysis treatment. All hospital admissions were reviewed and incidence of IRH was compared between PD and HD using Poisson regression. RESULTS: Of 264 incident chronic dialysis patients, 168 (64%) were eligible for both treatment modalities: 71 (42%) started outpatient PD and 97 (58%) started outpatient HD. The unadjusted and adjusted incidence rate ratios (IRR) of IRH did not differ significantly between PD and HD: 1.23 [95% confidence interval (CI) 0.65-2.32, p=0.37] and 1.14 (95% CI 0.58-2.23, p=0.71) respectively. There was no difference between PD and HD in the risk of access loss (28% vs 35%, p=0.73), modality change (22% vs 0%, p=0.10), or death (17% vs 6%, p=0.60) following hospitalization for infection. Patients starting outpatient treatment on PD versus HD were more likely to be hospitalized for peritonitis (IRR 3.20, 95% CI 1.16-9.09; p=0.029) and there was a trend for fewer hospitalizations for bacteremia (IRR 0.19, 95% CI 0.028-1.30; p=0.091). The risk of IRH did not differ between PD and HD in the subgroup of patients that received adequate predialysis care (IRR 1.16, 95% CI 0.59-2.27; p=0.67) or when patients starting outpatient HD with a central venous catheter were excluded (IRR 1.52, 95% CI 0.53-4.37; p=0.44). CONCLUSIONS: Patients that initiate outpatient peritoneal dialysis do not have a significantly increased risk of infection-related hospitalization compared to those that initiate outpatient hemodialysis.

The role of colonization pressure in nosocomial transmission of methicillin-resistant Staphylococcus aureus.

BACKGROUND: Colonized or infected patients are a major reservoir for patient-to-patient transmission of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals. Despite attempted adherence to recommended infection prevention and control procedures, a general medicine unit in our hospital continued to experience ongoing transmission of MRSA. The role that colonization pressure (CP) plays in nosocomial transmission of MRSA on a general medicine unit was assessed, and a threshold CP above which additional IP&C practices should be implemented was proposed. METHODS: From January 2005 to December 2006, all patients admitted to a 36-bed general medicine unit were screened on admission for MRSA. Monthly MRSA nosocomial incidence (new nosocomial cases x 1000/susceptible patient-days) and CP (number of MRSA patient-days x 100/total patient-days) were calculated. The relative risk (RR) of MRSA transmission above and below the median CP with 95% confidence interval was calculated. RESULTS: Twenty-one cases of nosocomially acquired MRSA were detected during the study period, with transmission occurring in 8 separate months. The median CP during the 2 years was 6.7%. The RR of MRSA acquisition increased as CP increased above the median (RR, 7.6; 95% CI: 1.1-52.6; P = .008). MRSA outbreaks were declared on 2 separate occasions, and, in each, the CP for the preceding month was greater than the median value of 6.7%. CONCLUSION: CP has a significant effect on the subsequent transmission of MRSA on a general medicine unit. Ongoing monitoring of CP provides the opportunity for early implementation of enhanced infection prevention and control practices and can potentially decrease nosocomial transmission of MRSA and prevent outbreaks.

Utility of environmental sampling for the prevention of transmission of vancomycin resistant enterococci (VRE) in hospitals.

BACKGROUND: Although vancomycin resistant enterococci (VRE) have been shown to contaminate environmental surfaces in the room of a patient infected or colonized with VRE there is limited evidence that links environmental contamination with acquisition. OBJECTIVES: To determine whether a policy of environmental sampling and room closure is more effective than cleaning and visual inspection of the room without culturing, in preventing the transmission of VRE to the next admitted patient. METHODS: The rooms of consecutive patients with VRE were alternatively managed according to either Protocol I (terminal cleaning, inspection and admission of new patient(s)) or Protocol II (terminal cleaning, environmental cultures and closing of the room pending negative results). The next admitted patient to all rooms had rectal swabs obtained for VRE within 24 hours of admission, three to five days after admission and upon discharge from the room and/or the facility. The proportion of patients who acquired the same strain of VRE after being admitted to rooms handled according to either Protocol I or Protocol II was compared. RESULTS: The risk of acquisition of VRE by patients admitted to a room managed according to Protocol I (1/19) was not significantly different than for patients admitted to a room managed according to Protocol II (0/12) (p=0.99). At least one positive environmental culture was obtained in 8/14 (57.1%) rooms managed according to Protocol II. CONCLUSIONS: Although VRE may be detected in the hospital environment there is insufficient evidence to conclude that routinely obtaining negative environmental cultures from the room of a patient infected or colonized with the organism is more effective in preventing VRE transmission to subsequent patients, provided the room is adequately cleaned and disinfected.