A multi-centre retrospective study of Nocardia speciation and antimicrobial susceptibility in Queensland, Australia.

The study aims to characterise the species identification and antimicrobial susceptibility testing (AST) results of Nocardial isolates from adult patients across major public hospitals in Queensland, Australia, over a 15-year period. A multi-centre retrospective observational study of Nocardia sp. isolates was conducted from 7 major public hospitals in Queensland, Australia, over a 15-year period. Clinical samples from patients aged ≥ 18 years that isolated Nocardia sp. were included. Demographic and clinical data were collected, along with species identification and AST results. Overall, 484 Nocardia sp. were isolated. Most patients were male (297, 61%) with a mean (IQR) age of 60 (51-75) and a median (IQR) Charlson Comorbidity Index of 4 (2-6). Of these, 239 (49%) patients were immunosuppressed. Organisms were most frequently isolated from sputum (174, 36%), and superficial swabs (102, 21%). Patients presented with pulmonary infections (165, 35%) and superficial skin and soft tissue infections (87, 18%) most commonly. One hundred (21%) isolates were deemed pulmonary colonisation and were not treated. Of the speciated organisms, N. nova complex was the most common (93, 19%), followed by N. farcinica complex (79, 16%). Organisms were reliably susceptible to linezolid (240/245, 98%), amikacin (455/470, 97%), and trimethoprim/sulfamethoxazole (459/476, 96%), but less so to imipenem (243/472, 51%) and ceftriaxone (261/448, 58%). This is the largest Australian description of Nocardia sp. to date. Given antimicrobials are often commenced prior to AST results and sometimes even speciation, characterisation of local species and antibiogram data is important to guide empiric choices and local guidelines.

Infectious diseases consultations at an Australian tertiary hospital: a review of 11,511 inpatient consultations.

BACKGROUND: Infectious diseases (ID) clinicians provide an important service within tertiary hospitals. However, as a largely consultation-based service, their value can be difficult to evaluate. AIMS: A review of 13.5 years of consultations was undertaken to define the scope of the service and any changes over time. METHODS: ID consultations at the Princess Alexandra Hospital are tracked on a database, recording information including the requesting team, indication for and outcome of the consult. Incident formal inpatient consultations between July 1999 and December 2012 were reviewed retrospectively. Phone consultations, repeat consultations and ID admissions were excluded. RESULTS: Eleven thousand five hundred and eleven consultations were identified, with annual consultations increasing significantly during this period. Overall, formal consultations were performed on 1.3% of admissions. Consultations were most commonly requested by orthopaedics (14.3%) and general medicine (11.4%). The two most common syndromes triggering a consult were bloodstream infection (13.9%) and complicated soft tissue infection (7.8%). The final diagnosis was most frequently osteomyelitis (7.9%). Staphylococcus aureus (19.4%) and Pseudomonas aeruginosa (8.3%) were the most commonly identified pathogens. CONCLUSION: The demand for ID consultations has increased over time and there are likely to be many drivers of this increase. Information derived from this audit can enhance the ID service by guiding service delivery, trainee education and informing funding or accreditation applications.