Retrospective Review of the Clinical Outcomes of Surgically Managed Patients with Intracranial Abscesses: A Single-Center Review.

OBJECTIVE: This study analyzed patient, radiologic, and clinical factors associated with operative brain abscesses and patients' functional outcomes. METHODS: A retrospective analysis was conducted of neurosurgical cases of brain abscesses from 2009 to 2019 at a Canadian center. Functional outcome was recorded as Modified Rankin Scale score and Extended Glasgow Outcome Scale score. Multivariate analysis was conducted to identify relevant prognostic factors. RESULTS: We identified 139 patients managed surgically for brain abscesses. Resection alone was performed in 64% of patients, whereas 26.6% underwent aspiration alone. Most were adults (93.2%) and male (68.3%). Immunocompromise risk factors included diabetes (24.5%), cancer (23.7%), and immunosuppressive therapy (11.5%). Likely sources were postoperative (17.3%), systemic spread (16.5%), and poor dentition (12.9%). Microorganisms cultured from abscess samples were mixed growth (28%), Streptococcus anginosus (24.5%), and Staphylococcus aureus (7.9%). Disposition was home (42.4%) or repatriation to a home hospital (50.4%). By Extended Glasgow Outcome Scale, 25.2% had an unfavorable outcome including a mortality of 11.5%. Factors on multivariate analysis associated with poor outcome included diabetes (odds ratio, 2.8; 95% confidence interval [CI], 1.2-5.0) and ventricular rupture (odds ratio, 5.0; 95% CI, 1.7-13.5; hazard ratio, 12; 95% CI, 3.9-37.0). Supratentorial superficial eloquently located abscess was also associated with poor outcome (hazard ratio, 5.5; 95% CI, 1.8-16.7). Outcomes were similar with surgical excision and aspiration. CONCLUSIONS: Ventricular rupture and diabetes are significant risk factors for poor outcomes in intraparenchymal brain abscesses. No clear difference in outcomes was found between surgical excision or aspiration in our retrospective cohort.

Purposeful microbiology comment added to urine cultures with Staphylococcus aureus increases orders for follow-up blood cultures.

INTRODUCTION: Patients with Staphylococcus aureus bacteriuria (SABU) often have underlying invasive disease, including S. aureus bacteremia (SAB). It has been proposed that most patients with SABU should have a blood culture done to rule out SAB. A preliminary audit suggested that our local hospitals had a low rate of follow-up blood culture orders for patients with SABU. In response to this, our microbiology laboratory changed the comment appended to urine cultures with growth of S. aureus to make a more assertive link between SABU and SAB and to recommend follow-up blood cultures. AIM: We designed a retrospective quasi-experimental study to see if the change in microbiology comment wording had an effect on clinician behaviour. We hypothesized that this simple comment change to make a more assertive link between SABU and SAB would lead to an increase in follow-up blood culture orders. METHODOLOGY: We used microbiology records to identify adult patients with urine cultures positive for Staphylococcus aureus at three acute-care hospitals in Hamilton, Ontario, Canada, for 1 year pre- and post-intervention. We recorded urine and blood culture results, timing, patient demographics, and in-hospital mortality. RESULTS: A total of 243 adult patients with urine cultures with S. aureus were identified for inclusion. The primary outcome was met, as there was a significant increase in blood culture orders between the pre-intervention and post-intervention groups (66.9 % vs 80.4 %). This difference was mainly driven by an increase for emergency department and urgent care patients (30.6 % vs 63.6 %). The inpatient group had a high baseline rate of blood culture orders that did not change significantly (80.0 % vs 84.7 %). There was no significant change in detection of SAB (23.5 % vs 32.7 %) or inpatient mortality (18.0 % vs 24.7 %). CONCLUSION: Our study shows that a simple, purposeful comment appended to urine cultures with S. aureus leads to a significant increase in follow-up blood culture orders.

Local audit of empiric antibiotic therapy in bacteremia: A retrospective cohort study.

BACKGROUND: It is unclear if a local audit would be useful in providing guidance on how to improve local practice of empiric antibiotic therapy. We performed an audit of antibiotic therapy in bacteremia to evaluate the proportion and risk factors for inadequate empiric antibiotic coverage. METHODS: This retrospective cohort study included patients with positive blood cultures across 3 hospitals in Hamilton, Ontario, Canada during October of 2019. Antibiotic therapy was considered empiric if it was administered within 24 hours after blood culture collection. Adequate coverage was defined as when the isolate from blood culture was tested to be susceptible to the empiric antibiotic. A multivariable logistic regression model was used to predict inadequate empiric coverage. Diagnostic accuracy of a clinical pathway based on patient risk factors was compared to clinician's decision in predicting which bacteria to empirically cover. RESULTS: Of 201 bacteremia cases, empiric coverage was inadequate in 56 (27.9%) cases. Risk factors for inadequate empiric coverage included unknown source at initiation of antibiotic therapy (adjusted odds ratio (aOR) of 2.76 95% CI 1.27-6.01, P = 0.010) and prior antibiotic therapy within 90 days (aOR of 2.46 95% CI 1.30-4.74, P = 0.006). A clinical pathway that considered community-associated infection as low risk for Pseudomonas was better at ruling out Pseudomonas bacteremia with a negative likelihood ratio of 0.17 (95% CI 0.03-1.10) compared to clinician's decision with negative likelihood ratio of 0.34 (95% CI 0.10-1.22). CONCLUSIONS: An audit of antibiotic therapy in bacteremia is feasible and may provide useful feedback on how to locally improve empiric antibiotic therapy.

Short-Course Antimicrobial Therapy for Pediatric Community-Acquired Pneumonia: The SAFER Randomized Clinical Trial.

Importance: Community-acquired pneumonia (CAP) is a common occurrence in childhood; consequently, evidence-based recommendations for its treatment are required. Objective: To determine whether 5 days of high-dose amoxicillin for CAP was associated with noninferior rates of clinical cure compared with 10 days of high-dose amoxicillin. Design, Setting, and Participants: The SAFER (Short-Course Antimicrobial Therapy for Pediatric Respiratory Infections) study was a 2-center, parallel-group, noninferiority randomized clinical trial consisting of a single-center pilot study from December 1, 2012, to March 31, 2014, and the follow-up main study from August 1, 2016, to December 31, 2019 at the emergency departments of McMaster Children's Hospital and the Children's Hospital of Eastern Ontario. Research staff, participants, and outcome assessors were blinded to treatment allocation. Eligible children were aged 6 months to 10 years and had fever within 48 hours, respiratory symptoms, chest radiography findings consistent with pneumonia as per the emergency department physician, and a primary diagnosis of pneumonia. Children were excluded if they required hospitalization, had comorbidities that would predispose them to severe disease and/or pneumonia of unusual origin, or had previous ß-lactam antibiotic therapy. Data were analyzed from March 1 to July 8, 2020. Interventions: Five days of high-dose amoxicillin therapy followed by 5 days of placebo (intervention group) vs 5 days of high-dose amoxicillin followed by a different formulation of 5 days of high-dose amoxicillin (control group). Main Outcomes and Measures: Clinical cure at 14 to 21 days. Results: Among the 281 participants, the median age was 2.6 (interquartile range, 1.6-4.9) years (160 boys [57.7%] of 279 with sex listed). Clinical cure was observed in 101 of 114 children (88.6%) in the intervention group and in 99 of 109 (90.8%) in the control group in per-protocol analysis (risk difference, -0.016; 97.5% confidence limit, -0.087). Clinical cure at 14 to 21 days was observed in 108 of 126 (85.7%) in the intervention group and in 106 of 126 (84.1%) in the control group in the intention-to-treat analysis (risk difference, 0.023; 97.5% confidence limit, -0.061). Conclusions and Relevance: Short-course antibiotic therapy appeared to be comparable to standard care for the treatment of previously healthy children with CAP not requiring hospitalization. Clinical practice guidelines should consider recommending 5 days of amoxicillin for pediatric pneumonia management in accordance with antimicrobial stewardship principles. Trial Registration: ClinicalTrials.gov Identifier: NCT02380352.

Review of high dose vancomycin in the treatment of Clostridioides difficile infection.

BACKGROUND: Guidelines recommend oral vancomycin as first-line therapy for Clostridioides difficile infection. Guideline recommendations vary regarding dosing of vancomycin. Our aim was to summarize the current evidence on the efficacy and adverse effects of high dose oral and vancomycin retention enema (>500 mg/day) for the treatment of C. difficile infection. METHODS: We searched clinical studies and major guidelines in the English language using MEDLINE, the Cochrane Library and Embase from 1985 until 15 April 2020. RESULTS: No evidence supports the use of high dose oral vancomycin in the treatment of severe C. difficile infection. Weak evidence from observational studies supports the use of high dose oral vancomycin in addition to intravenous metronidazole and high dose vancomycin retention enema in fulminant C. difficile infection. Vancomycin retention enema can be used in severe C. difficile infection when oral administration is not possible, or in conditions when the oral formulation cannot reach the colon such as Hartman's pouch, ileostomies, or colon diversions. CONCLUSIONS: The dosing schedules for oral vancomycin and vancomycin enemas are not clearly defined due to widely varying results in clinical studies. Large, comparative multicenter trials are urgently needed to define the role of high dose vancomycin in C. difficile infection.

Screening for and decolonization of Staphylococcus aureus carriers before total joint replacement is associated with lower S aureus prosthetic joint infection rates.

BACKGROUND: Prosthetic joint infections (PJI) can be devastating postoperative complications after total joint replacement (TJR). The role of decolonization of Staphylococcus aureus carriers prior to surgery still remains unclear, and the most recent guidelines do not state a formal recommendation for such strategy. Our purpose was to seek further evidence supporting preoperative screening and S aureus decolonization in patients undergoing TJR. METHODS: This was a quasiexperimental quality improvement study comparing a 5-year baseline of deep and organ-space PJIs (2005- 2010) to a 1-year intervention period (May 2015 to July 2016). The intervention consisted of nasal and throat screening for S aureus preoperatively and decolonization of carriers over 5 days prior to surgery. RESULTS: Prior to the intervention, we identified 42 deep and/or organ-space PJIs in 8,505 patients undergoing TJR (0.5%). S aureus was the causal microorganism in 28 of 42 (66.6%) cases. During the intervention, 22.5% (424 of 1,883) of patients were S aureus carriers. The PJI rate was similar overall (0.4%, 7 of 1,883; odds ratio, 0.75; 95% confidence interval, 0.34-1.67; P = .58), but there was a significant reduction in S aureus PJI to only 1 case during the intervention (odds ratio, 0.15; 95% confidence interval, 0.004-0.94; P = .039). CONCLUSIONS: Active screening for S aureus and decolonization of carriers prior to TJR was associated with a reduction in PJI due to S aureus, but no changes in overall PJI rates were observed.

The use of whole body diffusion-weighted post-mortem magnetic resonance imaging in timing of perinatal deaths.

OBJECTIVES: Diffusion-weighted MRI provides information regarding body water movement following death, which may be an imaging marker of post-mortem interval (time since death; PMI) or maceration (degree of tissue degradation during intra-uterine retention) in perinatal deaths. Our aim was to evaluate the relationship between maceration, PMI and body organ apparent diffusion coefficient (ADC) values in a cohort of subjects across a wide gestational range. MATERIALS: Whole body post-mortem MRI with diffusion-weighted imaging (DWI) sequences were performed at 1.5 T, with b values of 0, 500 and 1000 mm2/s. Mean ADC values were calculated from regions of interest (ROIs) placed in the lungs, myocardium, spleen, renal cortex, liver and psoas muscle by two independent readers. Multivariable regression analysis was performed against PMI, gestational age, post-mortem weight, maceration score and gender. RESULTS: Eighty perinatal deaths were imaged with mean gestational age of 32 weeks (18-41 weeks), of which 49 (61.3%) were male. The mean PMI was 8 days (1-18 days). Maceration scores were statistically significant predictive factors for ADC values in all included body organs except the lungs, but PMI was not a predictor for ADC values in any body organ. In the absence of maceration (n = 14), PMI was not statistically associated with ADC values in any of the body areas. The ratio of agreement in the majority of body areas was close to 1 (range between 0.95 and 1.10). CONCLUSION: Maceration, not PMI, is significantly associated with ADC values in perinatal deaths. Further research is needed to understand organ-specific changes in the post-mortem period.

Short-course antimicrobial therapy for paediatric respiratory infections (SAFER): study protocol for a randomized controlled trial.

BACKGROUND: Community-acquired pneumonia (CAP) is commonly diagnosed in children. The Infectious Disease Society of America guidelines recommend 10 days of high-dose amoxicillin for the treatment of non-severe CAP but 5-day "short course" therapy may be just as effective. Randomized trials in adults have already demonstrated non-inferiority of 5-day short-course treatment for adults hospitalized with severe CAP and for adults with mild CAP treated as outpatients. Minimizing exposure to antimicrobials is desirable to avoid harms including diarrhoea, rashes, severe allergic reactions, increased circulating antimicrobial resistance, and microbiome disruption. METHODS: The objective of this multicentre, randomized, non-inferiority, controlled trial is to investigate whether 5 days of high-dose amoxicillin is associated with lower rates of clinical cure 14-21 days later as compared to 10 days of high-dose amoxicillin, the reference standard. Recruitment and enrolment will occur in the emergency departments of McMaster Children's Hospital and the Children's Hospital of Eastern Ontario. All children in the study will receive 5 days of amoxicillin after which point they will receive either 5 days of a different formulation of amoxicillin or a placebo. Assuming a clinical failure rate of 5% in the reference arm, a non-inferiority margin of 7.5%, one-sided alpha set at 0.025 and power of 0.80, 270 participants will be required. Participants from a previous feasibility study (n = 60) will be rolled over into the current study. We will be performing multiplex respiratory virus molecular testing, quantification of nasopharyngeal pneumococcal genomic loads, salivary inflammatory marker testing, and faecal microbiome profiling on participants. DISCUSSION: This is a pragmatic study seeking to provide high-quality evidence for front-line physicians evaluating children presenting with mild CAP in North American emergency departments in the post-13-valent pneumococcal, conjugate vaccine era. High-quality evidence supporting the non-inferiority of short-course therapy for non-severe paediatric CAP should be generated prior to making changes to established guidelines. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02380352 . Registered on 2 March 2015.

Clot or not? An unusual case of false positive CTPA and an approach to diagnosis.

The case involves a 69-year-old female with severe, longstanding bronchiectasis secondary to childhood pertussis infection. She presented to the hospital and was thought clinically to have a pulmonary embolus. A CT pulmonary angiogram was performed, which was technically satisfactory. This revealed multiple, bilateral filling defects that were fairly convincing for pulmonary emboli. Further review of the CT scan not only revealed the extent of her bronchiectasis but also a number of enlarged bronchial arteries supplying the diseased lung. The pulmonary arterial filling defects arose suspiciously close to the bronchial arteries and the possibility of bronchial to pulmonary artery anastomoses was considered. Could the admixture of highly contrast-opacified pulmonary arterial blood with partially opacified systemic arterial blood cause the apparent filling defects? After further consideration, a second electrocardiography-gated CT angiogram was performed-this time in the systemic arterial phase but planned with two regions of interest sited over the main pulmonary artery and the aorta with the aim of triggering the scan with maximum contrast in the bronchial arteries, and as much contrast washout as possible in the pulmonary arteries. This study revealed a reversal of the CT pulmonary angiogram appearances with contrast now seen in the bronchial arteries and opacifying the sites of the previous filling defects in the pulmonary arteries. Thus, the filling defects were actually false positives caused by an admixture of highly opacified and part-opacified blood via bronchial artery anastomoses. In the context of a false-positive finding of pulmonary embolus on a background of severe bronchiectasis, unnecessary anticoagulation could have increased the risk of complications such as haemoptysis. This case report illustrates the importance of knowledge of potential false-positive findings in CT pulmonary angiography and describes a novel approach based on cardiac CT techniques to prove this.

Management and outcomes in patients with Staphylococcus aureus bacteremia after implementation of mandatory infectious diseases consult: a before/after study.

BACKGROUND: Infectious disease (ID) consultations have been shown to increase adherence to guidelines and decrease mortality for patients with Staphylococcus aureus bacteremia (SAB). Here, we assessed the impact of a mandatory ID consultation policy for SAB. METHODS: We retrospectively reviewed all consecutive adult patients with SAB at two tertiary care teaching hospitals in Hamilton, ON, Canada. Mandatory ID consults for SAB were implemented on January 1(st) 2012. We compared SAB cases in 2011 (control group) with those in 2012 (intervention group). Outcomes included adherence to the Infectious Diseases Society of America guidelines and patient outcomes. RESULTS: We reviewed 128 SAB cases in 2011 and 124 in 2012. The majority of S. aureus were methicillin-susceptible (97/128, 75.8 % in 2011 and 100/124, 80.6 % in 2012). ID involvement increased significantly from 93/128 (72.7 %) in 2011, to 103/124 (83.1 %) in 2012 (odds ratio [OR] 1.9, 95 % confidence interval [CI] 1.1-3.3, p = 0.047). There was also a significant decrease in the median time to ID involvement from 2 days to 1 (p = 0.001). In patients who survived the minimum treatment course (greater than 13 days), there was a significant improvement in adherence to IDSA guidelines in 2012 (65/102, 63.7 % vs. 77/96, 80.2 %; OR 2.3, 95 % CI 1.2-4.4, p = 0.01). Mortality and SAB relapse rates were similar in both groups. CONCLUSIONS: Creating an automated ID consultation for SAB led to an increase in involvement of ID, a significant decrease in time to ID involvement, and better adherence to IDSA guidelines. The study was not sufficiently powered to detect significant changes in mortality and SAB relapse rates.

A Controlled Quasi-Experimental Study of an Educational Intervention to Reduce the Unnecessary Use of Antimicrobials For Asymptomatic Bacteriuria.

BACKGROUND: Asymptomatic bacteriuria (ABU) should only be treated in cases of pregnancy or in-patients undergoing urologic procedures; however, unnecessary treatment of ABU is common in clinical practice. OBJECTIVE: To identify risk factors for unnecessary treatment and to assess the impact of an educational intervention focused on these risk factors on treatment of ABU. DESIGN: Quasi-experimental study with a control group. SETTING: Two tertiary teaching adult care hospitals. PARTICIPANTS: Consecutive patients with positive urine cultures between January 30th and April 17th, 2012 (baseline) and January 30th and April 30th, 2013 (intervention). INTERVENTION: In January 2013, a multifaceted educational intervention based on risk factors identified during the baseline period was provided to medical residents (monthly) on one clinical teaching unit (CTU) at one hospital site, with the CTU of the other hospital serving as the control. RESULTS: During the baseline period, 160/341 (46.9%) positive urine cultures were obtained from asymptomatic patients at the two hospitals, and 94/160 (58.8%) were inappropriately treated with antibiotics. Risk factors for inappropriate use included: female gender (OR 2.1, 95% CI 1.1-4.3), absence of a catheter (OR 2.5, 1.2-5), bacteriuria versus candiduria (OR 10.6, 3.8-29.4), pyuria (OR 2.0, 1.1-3.8), and positive nitrites (OR 2.2, 1.1-4.5). In 2013, only 2/24 (8%) of ABU patients were inappropriately treated on the intervention CTU as compared to 14/29 (52%) on the control CTU (OR 0.10; 95% CI 0.02-0.49). A reduction was also observed as compared to baseline on the intervention CTU (OR 0.1, 0.02-0.7) with no significant change noted on the control CTU (OR 0.47, 0.13-1.7). CONCLUSIONS: A multifaceted educational intervention geared towards medical residents with a focus on identified risk factors for inappropriate management of ABU was effective in reducing unnecessary antibiotic use.

Self-disinfecting sink drains reduce the Pseudomonas aeruginosa bioburden in a neonatal intensive care unit.

AIM: Water in sink drains is a known source of gram-negative bacteria. We aimed to evaluate the impact of self-disinfecting sink drains on the emission of aerosolised bacteria and on Pseudomonas aeruginosa acquisition among neonates. METHODS: Aerosol bacterial growth and patient Pseudomonas aeruginosa acquisition rates were measured at baseline (Phase One), for 13 months after sinks were relocated or redesigned during refurbishment (Phase Two) and for 13 months after introducing self-disinfecting sink drains (Phase Three). RESULTS: Cultures were positive for bacterial growth in 56%, 24% and 13% of the tested aerosols in Phases One, Two and Three, respectively. Comparing Phases Two and Three produced an odds ratio (OR) of 0.47, with a 95% confidence interval (CI) of 0.22-0.99 (p = 0.047), for all bacteria and an OR of 0.31 and CI of 0.12-0.79 (p = 0.013) for Pseudomonas aeruginosa. Rates of Pseudomonas aeruginosa positive clinical cultures were 0.34, 0.27 and 0.13 per 1000 patient days during the respective phases, with a significant increase of time to the next positive clinical culture in Phase Three. CONCLUSION: Self-disinfecting sink drains were superior to sink replacements in preventing emissions from aerosols pathogens and may reduce hospital-acquired infections. The bioburden reduction should be confirmed in a larger multicentre trial.

Multifaceted intervention to optimize antibiotic use for intra-abdominal infections.

OBJECTIVES: Implementing evidence-based practice guidelines is challenging. We used a multifaceted, continuous educational approach to disseminate an up-to-date internal guideline adapted from published guidelines for management of intra-abdominal infections (IAI). PATIENTS AND METHODS: The intervention consisted of continuing educational sessions, internal guideline pocket cards and posters with collaboration among all key stakeholders starting in December 2010. We emphasized risk stratification and the use of ceftriaxone/metronidazole for treatment of low-risk IAI, and discouraged the use of fluoroquinolones due to the high local resistance rates. We then compared patients with IAI before the intervention (April-November 2010) to those after implementation of the guideline (April-November 2011) in a surgical unit at a tertiary care teaching hospital in Hamilton, Ontario, Canada. Antibiotic use was measured in in-hospital days of antibiotic therapy (DOT) per 1000 patient days (PD). RESULTS: 152 and 145 patients with IAI were included in the pre- and post-intervention periods, respectively. There was a significant reduction in the proportion of patients who received ciprofloxacin therapy from 74% to 34% (OR 0.18, 95% CI 0.11-0.31) and in DOT/1000 PD from 221 to 74 (OR 0.3, 95% CI 0.2-0.3). Also, a reduction in the DOT/1000 PD for piperacillin/tazobactam was seen (from 116 to 67; OR 0.6, 95% CI 0.5-0.7). There was an increase in the use of ceftriaxone from 1.3% to 53% of patients (OR 85, 95% CI 20-515) and from 6 to 92 DOT/1000 PD (OR 17, 95% CI 10-25). This change in practice was sustained over >2 years since the end of the active intervention, as shown in the unit-wide antimicrobial utilization data. CONCLUSIONS: A multifaceted intervention aimed at all key stakeholders resulted in a high adherence to evidence-based treatment guidelines for IAI and has initiated a sustained culture change in prescribing of antibiotics.

Drug use prior to incarceration and associated socio-behavioural factors among males in a provincial correctional facility in Ontario, Canada.

OBJECTIVES: To describe the prevalence of drug use in males in a provincial detention centre during the year before incarceration and to examine the association between socio-demographic and behavioural factors and drug use. METHODS: In 2009, 500 adult males completed a survey after admission to a provincial detention centre in Ontario. Past-year prevalence rates were calculated for the use of opioids, cocaine, crack and methamphetamine, and by route of administration. Bivariate logistic regression was used to examine associations between drug use and socio-demographic and behavioural factors. RESULTS: More than 56% of participants reported use of opioids, cocaine, crack or methamphetamine in the previous year. Risk factors for blood-borne and sexually transmitted infections were commonly reported for the previous year: 12.2% had injected drugs, 78.0% had had unprotected sex, and 48.0% had had more than one sexual partner. In unadjusted analyses, participants who were older than 24 years were more likely to have used any drugs and to have injected drugs in the previous year. CONCLUSIONS: This study provides the first Canadian data in the past decade on drug use by recently incarcerated adults. We found that drug use and behaviours that increase the risk of transmission of sexually transmitted and blood-borne infections remain very common in this population. Incarceration provides an opportunity to provide services and links to programs for people who use drugs, which could decrease drug-related harms to individuals and society.