Old but not forgotten: Antibiotic allergies in General Medicine (the AGM Study).

OBJECTIVES: To determine the nature, prevalence and description accuracy of recorded antibiotic allergy labels (AALs) in a cohort of general medical inpatients, and to assess the feasibility of an oral antibiotic re-challenge study. DESIGN: Multicentre cross-sectional study. SETTING AND PARTICIPANTS: All patients admitted to the general medical units of Austin Health and Alfred Health, 18 May - 5 June 2015. MAIN OUTCOME MEASURES: Baseline demographics, medical and allergy history, infection diagnoses and antibiotic prescribing data for general medical inpatients were collected. A questionnaire was administered to clarify AAL history, followed by correlation of responses with electronic and admissions record descriptions. A hypothetical oral re-challenge in a supervised setting was offered to patients with low risk allergy phenotypes (non-immediate reaction, non-severe cutaneous adverse reaction, or unknown reaction more than 10 years ago). RESULTS: Of the 453 inpatients, 107 (24%) had an AAL (median age, 82 years; interquartile range, 74-87 years); 160 individual AALs were recorded, and there was a mismatch in AAL description between recording platforms in 25% of cases. Most patients with an AAL were women (64%; P < 0.001), and more presented with concurrent immunosuppression than those without an AAL (23% v 8%; P < 0.001). ß-Lactam penicillins were employed less frequently in patients with an AAL (16% v 35%; P = 0.02), while ceftriaxone (32% v 20%; P = 0.02) and fluoroquinolones (6% v 2%; P = 0.04) were used more often. Fifty-four per cent of patients with AALs were willing to undergo oral re-challenge, of whom 48% had a low risk allergy phenotype. CONCLUSIONS: AAL prevalence in general medical inpatients was 24%, and was associated with excessive use of broad spectrum antibiotics. Allergies in a large proportion of patients with AALs were incorrectly documented, and were non-immune-mediated and potentially amenable to oral re-challenge. A direct oral re-challenge study in carefully selected patients with low risk allergy phenotypes appears feasible.

The role of anaerobes in diabetic foot infections.

Diabetic foot infections (DFI) are a common cause of morbidity and, on occasion, even mortality. Infection can be either mono- or polymicrobial, with a wide variety of potential pathogens. Anaerobes may be involved, particularly in wounds that are deeper or more chronic, and are more frequently identified when using modern molecular techniques, such as 16s PCR and pyrosequencing. It remains unclear whether the presence of anaerobes in DFI leads to more severe manifestations, or if these organisms are largely colonizers associated with the presence of greater degrees of tissue ischemia and necrosis. Commonly used empiric antibiotic therapy for diabetic foot infections is generally broad-spectrum and usually has activity against the most frequently identified anaerobes, such as Peptostreptococcus and Bacteroides species. Adequate surgical debridement and, when needed, foot revascularization may be at least as important as the choice of antibiotic to achieve a successful treatment outcome.

COVID-19 infection among patients with cancer in Australia from 2020 to 2022: a national multicentre cohort study.

Background: The global COVID-19 pandemic disproportionately affected certain populations and its management differed between countries. This national study describes characteristics and outcomes of COVID-19 in patients with cancer in Australia. Methods: We performed a multicentre cohort study of patients with cancer and COVID-19 from March 2020 to April 2022. Data were analysed to determine varying characteristics between cancer types and changes in outcomes over time. Multivariable analysis was performed to determine risk factors associated with oxygen requirement. Findings: 620 patients with cancer from 15 hospitals had confirmed COVID-19. There were 314/620 (50.6%) male patients, median age 63.5 years (IQR 50-72) and majority had solid organ tumours (392/620, 63.2%). The rate of COVID-19 vaccination (≥1 dose) was 73.4% (455/620). Time from symptom onset to diagnosis was median 1 day (IQR 0-3), patients with haematological malignancy had a longer duration of test positivity. Over the study period, there was a significant decline in COVID-19 severity. Risk factors associated with oxygen requirement included male sex (OR 2.34, 95% CI 1.30-4.20, p = 0.004), age (OR 1.03, 95% CI 1.01-1.06, p = 0.005); not receiving early outpatient therapy (OR 2.78, 95% CI 1.41-5.50, p = 0.003). Diagnosis during the omicron wave was associated with lower odds of oxygen requirement (OR 0.24, 95% CI 0.13-0.43, p < 0.0001). Interpretation: Outcomes from COVID-19 in patients with cancer in Australia over the pandemic have improved, potentially related to changing viral strain and outpatient therapies. Funding: This study was supported by research funding from MSD.

Buruli ulcer disease in travelers and differentiation of Mycobacterium ulcerans strains from northern Australia.

Buruli ulcer (BU) is a necrotizing infection of skin and soft tissue caused by Mycobacterium ulcerans. In Australia, most cases of BU are linked to temperate, coastal Victoria and tropical, northern Queensland, and strains from these regions are distinguishable by variable-number tandem repeat (VNTR) typing. We present an epidemiological investigation of five patients found to have been infected during interstate travel and describe two nucleotide polymorphisms that differentiate M. ulcerans strains from northern Australia.

Managing Severe Community-Acquired Pneumonia Due to Community Methicillin-Resistant Staphylococcus aureus (MRSA).

Community-associated methicillin-resistant Staphylococcus aureus (MRSA) is a rare, but significant cause of community-acquired pneumonia (CAP). A number of virulence determinants have been implicated in the development of severe community MRSA pneumonia, characterized by multilobar cavitating necrosis in patients without usual risk-factors for pneumonia. Optimal management is uncertain, and is extrapolated from anecdotal experiences with small case series, randomized studies of hospital-acquired pneumonia, and laboratory investigations using in vitro experiments and animal models of MRSA pneumonia. Adequate clinical suspicion, early diagnosis and administration of appropriate antibiotics are necessary for best patient outcomes, although some patients will still do badly even with early anti-MRSA therapy. Vancomycin or linezolid have been recommended as first-line therapy, possibly in combination with other antibiotics. Newer antibiotics such as ceftaroline are still being evaluated.

New aspirations: the debate on aspiration pneumonia treatment guidelines.

Aspiration pneumonia occurs most commonly in patients with a predisposition to aspiration (eg, those with neurological bulbar dysfunction). There is limited evidence regarding the involvement of anaerobes in most cases of aspiration pneumonia. Most patients respond to treatment for aspiration pneumonia without specific anti-anaerobic therapy such as metronidazole. Metronidazole has adverse side effects, and widespread use where not indicated can promote carriage of multiresistant intestinal flora such as vancomycin-resistant enterococci. Use of metronidazole may be appropriate in patients with aspiration pneumonia and evidence of a lung abscess, necrotising pneumonia, putrid sputum or severe periodontal disease.

Pneumococcal pneumonia: potential for diagnosis through a urinary metabolic profile.

Pneumonia, an infection of the lower respiratory tract, is caused by any of a number of different microbial organisms including bacteria, viruses, fungi, and parasites. Community-acquired pneumonia (CAP) causes a significant number of deaths worldwide, and is the sixth leading cause of death in the United States. However, the pathogen(s) responsible for CAP can be difficult to identify, often leading to delays in appropriate antimicrobial therapies. In the present study, we use nuclear magnetic resonance spectroscopy to quantitatively measure the profile of metabolites excreted in the urine of patients with pneumonia caused by Streptococcus pneumoniae and other microbes. We found that the urinary metabolomic profile for pneumococcal pneumonia was significantly different from the profiles for viral and other bacterial forms of pneumonia. These data demonstrate that urinary metabolomic profiles may be useful for the effective diagnosis of CAP.

Large paraspinal abscess as a complication of infliximab therapy in Crohn's disease.

We report a 36-year-old man who developed a large epidural and paraspinal abscess as a complication of infliximab therapy being used for underlying Crohn's disease. Cultures of the collection grew methicillin-susceptible Staphylococcus aureus, and treatment consisted of abscess drainage, prolonged intravenous and oral flucloxacillin and temporary withholding of his infliximab. While infection-related complications are well described with infliximab therapy, this is the first description of a large paraspinal abscess with epidural extension.

The etiology of community-acquired pneumonia in Australia: why penicillin plus doxycycline or a macrolide is the most appropriate therapy.

BACKGROUND: Available data on the etiology of community-acquired pneumonia (CAP) in Australia are very limited. Local treatment guidelines promote the use of combination therapy with agents such as penicillin or amoxycillin combined with either doxycycline or a macrolide. METHODS: The Australian CAP Study (ACAPS) was a prospective, multicenter study of 885 episodes of CAP in which all patients underwent detailed assessment for bacterial and viral pathogens (cultures, urinary antigen testing, serological methods, and polymerase chain reaction). Antibiotic agents and relevant clinical outcomes were recorded. RESULTS: The etiology was identified in 404 (45.6%) of 885 episodes, with the most frequent causes being Streptococcus pneumoniae (14%), Mycoplasma pneumoniae (9%), and respiratory viruses (15%; influenza, picornavirus, respiratory syncytial virus, parainfluenza virus, and adenovirus). Antibiotic-resistant pathogens were rare: only 5.4% of patients had an infection for which therapy with penicillin plus doxycycline would potentially fail. Concordance with local antibiotic recommendations was high (82.4%), with the most commonly prescribed regimens being a penicillin plus either doxycycline or a macrolide (55.8%) or ceftriaxone plus either doxycycline or a macrolide (36.8%). The 30-day mortality rate was 5.6% (50 of 885 episodes), and mechanical ventilation or vasopressor support were required in 94 episodes (10.6%). Outcomes were not compromised by receipt of narrower-spectrum beta-lactams, and they did not differ on the basis of whether a pathogen was identified. CONCLUSIONS: The vast majority of patients with CAP can be treated successfully with narrow-spectrum beta-lactam treatment, such as penicillin combined with doxycycline or a macrolide. Greater use of such therapy could potentially reduce the emergence of antibiotic resistance among common bacterial pathogens.

SMART-COP: a tool for predicting the need for intensive respiratory or vasopressor support in community-acquired pneumonia.

BACKGROUND: Existing severity assessment tools, such as the pneumonia severity index (PSI) and CURB-65 (tool based on confusion, urea level, respiratory rate, blood pressure, and age >or=65 years), predict 30-day mortality in community-acquired pneumonia (CAP) and have limited ability to predict which patients will require intensive respiratory or vasopressor support (IRVS). METHODS: The Australian CAP Study (ACAPS) was a prospective study of 882 episodes in which each patient had a detailed assessment of severity features, etiology, and treatment outcomes. Multivariate logistic regression was performed to identify features at initial assessment that were associated with receipt of IRVS. These results were converted into a simple points-based severity tool that was validated in 5 external databases, totaling 7464 patients. RESULTS: In ACAPS, 10.3% of patients received IRVS, and the 30-day mortality rate was 5.7%. The features statistically significantly associated with receipt of IRVS were low systolic blood pressure (2 points), multilobar chest radiography involvement (1 point), low albumin level (1 point), high respiratory rate (1 point), tachycardia (1 point), confusion (1 point), poor oxygenation (2 points), and low arterial pH (2 points): SMART-COP. A SMART-COP score of >or=3 points identified 92% of patients who received IRVS, including 84% of patients who did not need immediate admission to the intensive care unit. Accuracy was also high in the 5 validation databases. Sensitivities of PSI and CURB-65 for identifying the need for IRVS were 74% and 39%, respectively. CONCLUSIONS: SMART-COP is a simple, practical clinical tool for accurately predicting the need for IRVS that is likely to assist clinicians in determining CAP severity.

Endoscopic investigation in non-iron deficiency anemia: a cost to the health system without patient benefit.

BACKGROUND AND AIMS: The indication for endoscopy to investigate anemia of causes other than iron deficiency is not clear. Increasing numbers of endoscopic procedures for anemia raises concerns about costs to the health system, waiting times, and patient safety. The primary aim of this study was to determine the diagnostic yield of endoscopy in patients referred to undergo investigation for anemia. Secondary aims were to identify additional factors enabling the risk stratification of those likely to benefit from endoscopic investigation, and to undertake a cost analysis of performing endoscopy in this group of patients. METHODS: We performed a retrospective review of endoscopy referrals for the investigation of anemia over a 12-month period at a single center. The patients were divided into three groups: those who had true iron deficiency anemia (IDA), tissue iron deficiency without anemia (TIDWA), or anemia of other cause (AOC). Outcome measures included finding a lesion responsible for the anemia and a significant change of management as a result of endoscopy. A costing analysis was performed with an activity-based costing method. RESULTS: We identified 283 patients who underwent endoscopy to investigate anemia. A likely cause of anemia was found in 31 of 150 patients with IDA (21 %) and 0 patients in the other categories (P < 0.001). A change of management was observed in 35 patients with IDA (23 %), 1 of 14 patients with TIDWA (7.14 %), and 8 of 119 patients with AOC (6.7 %) (P < 0.001). The cost of a single colonoscopy or gastroscopy was approximated to be $ 2209. CONCLUSIONS: Endoscopic investigation for non-IDA comes at a significant cost to our institution, equating to a minimum of $ 293 797 per annum in extra costs, and does not result in a change of management in the majority of patients. No additional factors could be established to identify patients who might be more likely to benefit from endoscopic investigation. The endoscopic investigation of non-IDA should be minimized.

Clinical features associated with bacteremia due to heterogeneous vancomycin-intermediate Staphylococcus aureus.

We assessed all episodes of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia at our hospital during a 12-month period (n=53) and compared those due to heterogeneous vancomycin-intermediate S. aureus (hVISA; n = 5, 9.4%) with those due to vancomycin-susceptible MRSA (n=48). Patients with hVISA bacteremia were more likely to have high bacterial load infections (P=.001), vancomycin treatment failure (persistent fever and bacteremia for >7 days after the start of therapy; P<.001), and initially low serum vancomycin levels (P=.006). These clinical markers of hVISA bacteremia may help focus diagnostic efforts and treatment.

Treatment outcomes for serious infections caused by methicillin-resistant Staphylococcus aureus with reduced vancomycin susceptibility.

Although infections caused by methicillin-resistant Staphylococcus aureus with reduced vancomycin susceptibility (SA-RVS) have been reported from a number of countries, including Australia, the optimal therapy is unknown. We reviewed the clinical features, therapy, and outcome of 25 patients with serious infections due to SA-RVS in Australia and New Zealand. Eight patients had endocarditis, 9 had bacteremia associated with deep-seated infection, 6 had osteomyelitis or septic arthritis, and 2 had empyema. All patients had received vancomycin before the isolation of SA-RVS, and glycopeptide treatment had failed for 19 patients (76%). Twenty-one patients subsequently received active treatment, which was effective for 16 patients (76%). Eighteen patients received linezolid, which was effective in 14 (78%), including 4 patients with endocarditis. Twelve patients received a combination of rifampicin and fusidic acid. Surgical intervention was required for 15 patients (60%). Antibiotic therapy, especially linezolid with or without rifampicin and fusidic acid, in conjunction with surgical debulking is effective therapy for the majority of patients with serious infections (including endocarditis) caused by SA-RVS.

Post-traumatic endophthalmitis.

OBJECTIVE: To establish risk factors for the occurrence of post-traumatic endophthalmitis, to observe the efficacy of prophylaxis, and to describe the clinical features of post-traumatic endophthalmitis. DESIGN: Partially prospective consecutive case-control study. PARTICIPANTS: A total of 250 consecutive patients admitted to a single ophthalmic hospital with open globe injuries during a 3-year period were included. METHODS: Patients with post-traumatic endophthalmitis were identified prospectively and added to an endophthalmitis database. All open globe injuries during the same time period were identified through a retrospective search of inpatient admissions, and their charts were reviewed. Information collected from all patient files included patient age; gender; injury setting (indoor/outdoor); wound contamination; nature of injury (site on eye, lens involvement, retained intraocular foreign body); mechanism of injury (penetration/perforation/rupture/ruptured surgical wound); prophylactic antibiotic administration, including route and timing; timing of primary repair; lensectomy at the time of primary repair; and depot corticosteroid at the time of primary repair. Any association between these parameters and the subsequent development of endophthalmitis was investigated. Any association between endophthalmitis and final visual acuity (VA) and also enucleation was evaluated. MAIN OUTCOME MEASURE: Development of endophthalmitis. RESULTS: The frequency of endophthalmitis after open globe injury was 6.8%. The following factors were associated with the subsequent development of endophthalmitis by univariate analysis: dirty wound (14.3% vs. 4.1%, P = 0.01), retained intraocular foreign body (13.0% vs. 4.4%, P = 0.02), lens capsule breach (12.8% vs. 3.2%, P = 0.01), delayed primary repair (> or =12 hours) (11.3% vs. 2.9%, P = 0.02), and rural address (10.1% vs. 4.3%, P = 0.07). Risk factors identified after multivariate analysis were dirty injury (odds ratio [OR], 5.3; 95% confidence interval [CI)], 1.5-18.7), breach of lens capsule (OR, 4.4; 95% CI, 1.2-15.6), and delay in primary repair (per hour: OR, 1.013; 95% CI, 1.002-1.024). None of the following factors was found to be associated with post-traumatic endophthalmitis: patient age, gender, injury setting, site of injury on eye, mechanism of injury, antibiotic administration, lensectomy at the time of primary repair, and depot corticosteroid at the time of primary repair. Final VA tended to be worse in eyes with endophthalmitis (P = 0.08). Endophthalmitis did not significantly influence the frequency of enucleation/evisceration (5.9% vs. 4.3%, P = 0.55). CONCLUSIONS: Delay in primary repair, ruptured lens capsule, and dirty wound were each independently associated with the development of post-traumatic endophthalmitis. Patients with > or =2 of these 3 risk factors had a particularly high frequency of infection.

Infectious mononucleosis.

BACKGROUND: Infectious mononucleosis is caused by the ubiquitous Epstein-Barr virus. It is a common condition usually affecting adolescents and young adults. Most cases are mild to moderate in severity with full recovery taking place over several weeks. More severe cases and unusual complications occasionally occur. OBJECTIVE: After presenting a case of severe infectious mononucleosis, the spectrum of disease is given. Diagnosis and complications are reviewed as well as management including the possible role for antiviral medications or corticosteroid therapy. DISCUSSION: The majority of cases of infectious mononucleosis are self limiting and require only supportive care. More severe cases, although unusual, may require admission to hospital and even to an intensive care unit. Corticosteroid therapy may be indicated for severe airway obstruction or other severe complications, but should be avoided unless the benefits outweigh potential risks. Antiviral therapy has no proven benefit.