Use of thioglycolate broth as a pre-analytic transport medium in the diagnosis of prosthetic joint infection.

OBJECTIVES: This study aimed to investigate whether adding tissue samples directly into thioglycolate (TG) broth yielded a greater number of anaerobic organisms than freshly sampled tissue in suspected hip and knee prosthetic joint infections (PJIs). PATIENTS AND METHODS: Between January 2017 and December 2020, a total of 90 patients (46 males, 44 females; median age: 71.7 years; range, 50.8 and 87.8 years) who underwent revision hip or knee arthroplasty were included. Intraoperative samples were taken, with five placed in TG broth and five in standard containers (PC) with subsequent aerobic and anaerobic culturing conducted. Demographic and baseline data of the patients were recorded. The primary outcome was positive bacterial growth from a PJI specimen inoculated directly into TG broth at the time of collection or standard PJI specimen processing. Secondary outcomes investigated were the presence of Cutibacterium acnes (C. acnes) and the curative success of revision procedure. RESULTS: A total of 900 samples (450 PC and 450 TG) were taken from 90 revision arthroplasty patients (47 knees and 43 hips). There was no statistically significant difference in the number of positive bacterial growth samples between TG broth and standard processing (p=0.742). This was consistent with subgroup analysis analyzing C. acnes (p=0.666). CONCLUSION: In hip and knee arthroplasty, there is no benefit in substituting or adding TG broth as a culture medium to better identify both general bacterial species and C. acnes infections specifically. However, the use of TG may be useful in confirming a true positive result for infection.

Adherence to antimicrobial prophylaxis guidelines in cardiac implantable electronic device procedures in two Australian teaching hospitals.

Objective This study investigated antibiotic prophylaxis (AP) guideline adherence and the cardiac implantable electronic device (CIED) infection rate in two major Australian public teaching hospitals. Methods In a retrospective observational study, the medical records of patients who underwent CIED procedures between January and December 2017 were reviewed (Hospital A, n = 400 procedures; Hospital B, n = 198 procedures). Adherence to AP guidelines was assessed regarding drug, dose, timing, route and frequency. Infection was identified using follow-up documentation. Results AP was administered in 582 of 598 procedures (97.3%). Full guideline adherence was observed in 33.9% of procedures (203/598) and differed significantly between Hospitals A and B (47.3% vs 7.1%, respectively; P < 0.001). Common reasons for non-adherence were the timing of administration (42.3% vs 60.6% non-adherent in Hospitals A and B, respectively; P < 0.001) and repeat dosing (19.3% vs 78.8% non-adherent in Hospitals A and B, respectively; P < 0.001). Twenty infections were identified over 626.6 patient-years of follow-up (mean (±s.d.) follow-up 1.0 ± 0.3 years). The infection rate was 3.19 per 100 patient-years (P = 0.99 between hospitals). Two devices were removed due to infection; no patients died from CIED infection. Conclusions Although the rate of serious CIED infection was low, there was evidence of highly variable and suboptimal antibiotic use, and potential overuse of AP. What is known about the topic? Previous Australian studies have revealed high rates of inappropriate surgical AP. CIED infections are potentially life threatening, but can be avoided through effective use of AP. However, prolonged durations of AP in this setting may also result in complications, including Clostridioides difficile infection. What does this paper add? This study, the first to our knowledge to focus specifically on adherence to Australian guidelines for AP in CIED procedures, highlighted several common issues between AP in this setting and surgical and procedural AP more broadly. 'Early' and 'late' dose administration and extended post-procedural AP were common. Only 34% of prescriptions fully adhered to the guidelines; practices varied significantly between the two hospitals. What are the implications for practitioners? There is a clear need for institution-specific antimicrobial stewardship strategies to optimise AP in CIED procedures, aligned with the Antimicrobial Stewardship Clinical Care Standard. Patients are being placed at potentially avoidable risk of both complications of extended durations of AP and CIED infection, although the rate of serious CIED infection was low. A standardised approach to surveillance of CIED infections and prospective multisite audits of AP in CIED procedures using a validated tool, such as the Surgical National Antimicrobial Prescribing Survey, are recommended to better inform evidence-based practice. Potential strategies to optimise guideline adherence include prescribing support in patients with immediate penicillin hypersensitivity or methicillin-resistant Staphylococcus aureus colonisation, optimising the in-patient location of drug administration to promote timely dosing, limiting inappropriate post-procedural prophylaxis and routine S. aureus screening and decolonisation.

Adaptation of a hospital electronic referral system for antimicrobial stewardship prospective audit and feedback rounds.

OBJECTIVE: To evaluate the impact of the adaptation of an existing electronic referral application for use in antimicrobial stewardship prospective audit and feedback rounds (antimicrobial rounds). DESIGN: Retrospective, single-centre observational study between March 2015 and February 2016. SETTING: A new quaternary referral centre. STUDY PARTICIPANTS: Adults referred for antimicrobial rounds outside of the intensive care and haematology units. INTERVENTION: Adaptation of an electronic referral application used by medical and allied health staff. A questionnaire-style referral form was designed to capture patient clinical details using a combination of free text and dropdown menus. Clinical pharmacists were educated and granted access to the system. MAIN OUTCOME MEASURES: The proportion of completed electronic referrals of total round reviews by month for the 12 months after implementation. The time from request to completion of reviews. The impact on adherence to advice provided on rounds. The impact on the institutional usage of broad-spectrum antibiotics: glycopeptides, carbapenems, third and fourth generation cephalosporins, fluoroquinolones and piperacillin/tazobactam. RESULTS: Over the study period, the proportion of electronic referrals of completed antimicrobial round reviews increased from 59% to 88% (P < 0.001); 75.7% of accepted electronic referrals were seen within 48 h of request. The proportion of advice ignored fell from 18% to 8.5% (P < 0.001). Piperacillin/tazobactam, fluoroquinolone and glycopeptide usage decreased. CONCLUSIONS: The adaptation of an electronic referral application for antimicrobial rounds was associated with increased adherence to advice and reduction in use in target antibiotics. Our model is now used at other institutions.

Optimizing adherence to advice from antimicrobial stewardship audit and feedback rounds.

We examined adherence to antimicrobial stewardship prospective audit and feedback rounds in a rehabilitation service compared with the remainder of the acute hospital, and explored the reasons for this. Between October 2014 and December 2015, we retrospectively assessed the rate of non-adherence to advice from antimicrobial stewardship prospective audit and feedback rounds between the rehabilitation service and the acute hospital, along with the source of the patient referral. Compared with the rehabilitation service, acute hospital medical staff were almost twice as likely to not adhere to advice provided on antimicrobial stewardship prospective audit and feedback rounds (13.8% vs. 7.6%, p < 0.0001, relative risk 1.8 [95% confidence interval 1.3, 2.5]). In the rehabilitation service, referrals were more likely to come from medical staff (61.9% vs. 16.3%, p < 0.0001). These findings may be explained by regular, direct engagement of the antimicrobial stewardship team with the rehabilitation service clinical team, a model potentially applicable to other settings.

Infected endoluminal stent-graft: implications for endotension, late endoleaks, and prophylactic antibiotics.

PURPOSE: To retrospectively review a case of stent-graft infection that presented as continued aneurysm expansion after endoluminal repair. CASE REPORT: A 75-year-old man with an asymptomatic 6.1-cm abdominal aortic aneurysm (AAA) was treated with a Talent stent-graft, which was complicated by postimplantation syndrome. At 1 year, a secondary intervention was performed for migration with type I endoleak. Despite the absence of a demonstrable endoleak thereafter, the AAA continued to expand until it was 9 cm in diameter and symptomatic. At this stage, 6 months after the secondary procedure, the graft was explanted and an axillobifemoral graft inserted. Propionibacterium acnes was cultured from all specimens of thrombus, aortic wall, and graft. The patient recovered and was asymptomatic until his death from myocardial infarction 6 months after discharge. CONCLUSIONS: Stent-graft infection may be a cause of unexplained endotension. Special culture techniques may be required to identify the infecting organism. Prophylactic antibiotics against skin organisms should be considered for all implantations and arterial diagnostic and therapeutic procedures traversing a stent-graft.

Epidemiological features and control of an outbreak of scarlet fever in a Perth primary school.

Scarlet fever was associated with feared outbreaks and mortality in the 19th Century. It occurs sporadically in modern society and infection is readily treated with antibiotics. We report on a scarlet fever outbreak in children attending a primary school in Perth, Western Australia, in late 2003. A total of 13 cases were identified over a five week period. Six of the cases were pre-primary children (ages 4 to 5) from the same class of 26 children (attack rate 23.1%). Three of the remaining seven cases were older siblings of pre-primary cases who developed scarlet fever after their younger siblings. Screening of the children and teachers from the two pre-primary classes at the school yielded 12 positive pharyngeal swabs for group A Streptococcus. Emm-typing of the screening isolates indicated that a common strain was circulating within the outbreak pre-primary class, with four of six isolates identified as emm-type 3. The overall group A Streptococcus carriage rate in screened students in this class was 31.6 per cent and the carriage rate for emm-type 3 was 21.1 per cent. Carriers were treated with oral penicillin V to eradicate carriage and control the outbreak. No further cases of scarlet fever were reported after the treatment of pharyngeal carriers. Outbreaks of scarlet fever still occur in young children and identification and treatment of carriers may still be valuable.