JAMMI最新文献

Background: Whipple's disease is a rare systemic disorder caused by infection with Tropheryma whipplei. An increased number of cases of this infectious disease have recently been noted by practitioners in southern New Brunswick, Canada. We analyzed a series of Whipple's disease cases so as to better understand factors that could contribute to its increased incidence in southern New Brunswick.

Methods: We conducted a retrospective case series of patients diagnosed with Whipple's disease in the health zone surrounding Saint John, New Brunswick, between January 2020 and January 2024. Demographic data, medical histories, patient assessments, pertinent investigations, and clinical outcomes were reviewed for each case and extracted for further analysis.

Results: A total of four cases of Whipple's disease were identified. The estimated annual incidence was 5.7 cases per 1 million during the study time frame - a value nearly six times greater than the incidence proposed in the literature. The four cases varied widely in terms of presenting clinical features. No unifying environmental exposure was immediately apparent among the identified patients.

Conclusion: The recent incidence of Whipple's disease in southern New Brunswick is higher than expected based on existing literature. Whipple's disease has a predilection for White and elderly individuals, and these populations have higher prevalence in southern New Brunswick when compared to national averages. Environmental triggers of Whipple's disease have been previously described, and such a trigger may have been present among the study population. Large-scale epidemiologic studies are necessary to further assess possible demographic, environmental, and disease-related triggers of Whipple's disease in Canada.

Background: Colonization with enteropathogens such as Clostridioides difficile has been linked to clinical infection with these same organisms. C. difficile infection (CDI) is associated with increased morbidity and mortality in patients undergoing hematopoietic cell transplantation (HCT). The study aims to evaluate the utility of existing C. difficile stool detection methods used during pre-transplant planning to identify individuals at high risk of developing CDI within 3 months post-transplant.

Methods: A prospective cohort study of patients undergoing HCT at a large quaternary care centre was conducted to assess the impact of baseline C. difficile colonization on downstream CDI outcomes. Baseline stool samples were collected prior to admission for conditioning chemotherapy, which were evaluated for C. difficile colonization using routine, short-turnaround-time clinical approaches by performing glutamine dehydrogenase (GDH) enzyme immunoassay (EIA) and toxin B gene (tcdB) polymerase chain reaction (PCR). Clinical data and outcomes were reviewed 3 months post-transplant. Test characteristics for using baseline C. difficile colonization as a screening tool for predicting subsequent CDI were calculated.

Results: Sixty patients were enrolled. The prevalence of C. difficile colonization (GDH positive) among patients undergoing HCT was 10% (6/60). Ten patients developed CDI within 3 months post-transplant, 50% of whom were colonized at baseline. Among the colonized patients, 83% (5/6) developed CDI during the follow-up period. Asymptomatic C. difficile colonization pre-admission had a 98% specificity (95% CI 89% to 100%), 50% sensitivity (95% CI 19% to 81%), 83% positive predictive value (95% CI 36% to 100%), and 91% negative predictive value (95% CI 80% to 97%) for developing subsequent CDI.

Conclusions: Pre-admission C. difficile screening could support targeted prophylactic strategies for patients at risk of developing CDI, and this approach warrants further evaluation.

Mycobacterium abscessus, a rapidly growing and frequently multidrug-resistant non-tuberculous mycobacterium, has been linked to cutaneous infections in both immunocompetent and immunocompromised individuals through inoculation via skin-traumatizing procedures such as tattooing. Here we describe two patients with culture-confirmed M. abscessus cutaneous infections acquired from the same tattoo studio in Calgary, Canada. Both patients developed dozens of erythematous papules at the site of inoculation within 2 weeks of a new tattoo using the same grey-wash ink. Despite recommendation for antimicrobial therapy, both patients independently elected to pursue surgical excision and observation. Following excision of multiple papules, both patients showed evidence of infection resolution within 10 weeks, without any evidence of relapsed infection. Conventional treatment of M. abscessus skin and soft tissue infections typically involves susceptibility-guided multidrug regimens for several months and is commonly associated with significant medication toxicity. These cases demonstrate that observation, potentially augmented with surgical removal, may be effective alternatives, especially in immunocompetent individuals with localized infections, which avoids the need for antibiotics.

Background: Oxacillin-susceptible methicillin-resistant Staphylococcus aureus (OS-MRSA) is a phenotype of S. aureus that presents as methicillin susceptible on traditional screening tests but may have a resistant phenotype, leading to clinical failure.

Methods: An isolate of S. aureus screened negative for methicillin resistance in a case of septic bursitis in a 75-year-old female. After failure to improve on cefazolin, a second aspirate was performed and sent for testing. The second sample strain retrieved had an additional PBP2a lateral flow performed, demonstrating the presence of mecA products.

Results: Both S. aureus isolates proved to be identical on pulsed-field gel electrophoresis and had faint positive PBP2a bands on lateral flow, despite screening negative for methicillin resistance on oxacillin and cefoxitin testing. A point mutation was found in the mecA start codon, which could explain the OS-MRSA phenotype. Neither oxacillin nor cefoxitin screening tests were positive following a cefoxitin induction assay that was used locally to promote a methicillin-resistant phenotype in small-colony variant S. aureus (SCV).

Conclusions: OS-MRSA is a rare but documented phenotype of S. aureus that has the potential to escape typical screening. Simple mutations may lead to reversal under selection pressure. Failure to respond to standard-of-care therapy for methicillin-sensitive S. aureus should prompt additional testing. Such methods could include a PBP2a immunoassay with high sensitivity. The patient recovered by using an antibiotic of a different class, trimethoprim-sulfamethoxazole, for which the isolate tested sensitive.

Background: When bloodstream infection (BSI) occurs in patients with a central venous catheter (CVC), the catheter may be the original source (catheter-related, CR) or may become a source for persistent infection. BSI should prompt an evaluation of CVC necessity, but there are challenges associated with CVC replacement.

Methods: An online multinational survey was sent to professional societies of specialties involved in treating patients who have BSI and a CVC. Clinicians were asked to choose retention versus replacement for scenarios involving different CVC types, infection sources, and pathogens. Additional questions explored central venous catheter-related bloodstream infection (CRBSI) diagnosis, management, and willingness to enrol patients in a randomized controlled trial (RCT).

Results: A total of 220 physicians responded. For peripherally inserted central catheter-related BSI, most favoured CVC replacement, although there was variability across pathogens (Candida spp 100%, Staphlococcus aureus 99%; Pseudomonas aeruginosa 94%; Enterococcus spp 75%; Enterobacterales 66%; coagulase-negative staphylococci 58%). For tunnelled CVC-related BSI, replacement recommendations also varied (Candida 99%; S. aureus 95%; P. aeruginosa 87%; Enterococcus spp 58%; Enterobacterales 44%; coagulase-negative staphylococci 33%). For catheter-unrelated BSI, there was a lower tendency to replace the CVC. For each combination of pathogen and CVC type, a majority (>50%) of participants reported willingness to enrol patients into an RCT comparing CVC replacement versus retention; the only exceptions below 50% were S. aureus (44%) and Candida spp (44%) CRBSIs from short-term non-tunnelled CVCs.

Conclusion: There is heterogeneity in CVC management practices and stated equipoise for an RCT comparing management approaches for a range of CVC types, BSI sources, and pathogens.

Background: Clostridioides difficile is a bacillus that can colonize the intestinal tract. C. difficile infection (CDI) is a common, health care-associated disease often coinciding with antibiotic use, with presentation ranging from diarrhea to toxic megacolon and death. However, individuals can carry the pathogen without exhibiting symptoms of disease. C. difficile carriers may serve as an important reservoir for in-hospital transmission of C. difficile. The objective of this study was to assess the role asymptomatic C. difficile carriers may play in pathogen transmission.

Methods: In this retrospective cohort study, rectal swabs collected to test for antimicrobial-resistant organisms either upon admission or during the hospital stay were used to test for asymptomatic C. difficile carriage using molecular testing, with positive samples cultured and subsequently sequenced. Sampling occurred across three tertiary care hospitals with predominantly multi-bedded rooms. A whole-genome single-nucleotide variant phylogenetic tree was then constructed and closely related samples from patients that had spatial and temporal in-hospital overlap were identified as putative transmission events.

Results: Approximately 11% of the 1,467 patients tested were carriers of C. difficile. Seventy-four of the carriers were culture-positive, of which 43 had a suitable sequence for typing. Of the sequenced samples, 40% were identified as belonging to a potential transmission event. Six different potential transmission groups were identified, with the largest putative transmission group spanning two hospitals and 6 months.

Conclusions: Our results suggest that asymptomatic transmission in hospital settings may be much more common than previously thought, with asymptomatic individuals colonized with C. difficile providing a sizable source of transmission of the pathogen.

Background: There are associated adverse effects with intravenous (IV) vancomycin, yet there is a paucity of published literature surveying the appropriateness of use. The objective of the study was to assess the appropriateness of IV vancomycin prescriptions at a Canadian acute care hospital.

Methods: A pilot, pragmatic antimicrobial stewardship initiative using prospective audit and feedback (PAF) was conducted on incident IV vancomycin prescriptions for 4 weeks in 2022. The primary outcome was the percentage of IV vancomycin prescriptions assessed as appropriate against institutional prescribing guidelines. The secondary outcomes were to evaluate factors affecting appropriateness and to determine the number and types of ASP recommendations where IV vancomycin was assessed as suboptimal.

Results: Out of 109 prescriptions audited, 43 (39%) were assessed to be suboptimal. Discontinuing or changing the agent was recommended in 39 cases (91%) and regimen optimization (duration or frequency change) was only recommended in only 4 (9%). ASP recommendations were fully or partially accepted in 88%. Infectious disease consultation (IDC) was associated with greater appropriateness (83% versus 53%; p = 0.004), as was Methicillin resistant Staphylococcus aureus (MRSA) colonization (75% versus 55%; p = 0.047), but not acute kidney injury (AKI) (62% versus 60%; p = 0.889). Adjusting for age, AKI and MRSA colonization, IDC remained a significant predictor of vancomycin appropriateness (adjusted odds ratio [aOR] = 4.27, [95% CI 1.44 to 12.70]; p = 0.009).

Conclusions: Prospective audit and feedback demonstrated inappropriate IV vancomycin use at our centre and an opportunity for quality improvement.