Appropriateness of antibiotic prescribing in the Emergency Department.

Background: Antibiotics are some of the most commonly prescribed drugs in the Emergency Department (ED) and yet data describing the overall appropriateness of antibiotic prescribing in the ED is scarce. Objectives: To describe the appropriateness of antibiotic prescribing in the ED. Methods: A retrospective, observational study of current practice. All patients who presented to the ED during the study period and were prescribed at least one antibiotic were included. Specialists from Infectious Disease, Microbiology and Emergency Medicine and a Senior Pharmacist assessed antibiotic appropriateness against evidence-based guidelines. Results: A total of 1019 (13.6%) of patient presentations involved the prescription of at least one antibiotic. Of these, 640 (62.8%) antibiotic prescriptions were assessed as appropriate, 333 (32.7%) were assessed as inappropriate and 46 (4.5%) were deemed to be not assessable. Adults were more likely to receive an inappropriate antibiotic prescription than children (36.9% versus 22.9%; difference 14.1%, 95% CI 7.2%-21.0%). Patients who met quick Sepsis-related Organ Failure Assessment (qSOFA) criteria were more likely to be prescribed inappropriate antibiotics (56.7% versus 36.1%; difference 20.5%, 95% CI, 2.4%-38.7%). There was no difference in the incidence of appropriate antibiotic prescribing based on patient gender, disposition (admitted/discharged), reason for antibiotic administration (treatment/prophylaxis) or time of shift (day/night). Conclusions: Inappropriate administration of antibiotics can lead to unnecessary adverse events, treatment failure and antimicrobial resistance. With over one in three antibiotic prescriptions in the ED being assessed as inappropriate, there is a pressing need to develop initiatives to improve antibiotic prescribing to prevent antibiotic-associated patient and community harms.

Is it time for a culture change? Blood culture collection in the emergency department.

OBJECTIVE: To describe how frequently blood cultures (BCs) are obtained in the ED and to describe the incidence of true- and false-positive BC results. METHODS: Retrospective descriptive study of all patients presenting to a tertiary-level, mixed Australian ED over a 15 month period. RESULTS: A total of 3617 (3.67%) patients had BCs collected. Around one (12.1%) in eight of these BCs were positive; nearly half (45.2%) of which were identified as a false positive. CONCLUSIONS: BCs are a common investigation in the ED with a high false-positive rate. Strategies are required to reduce false positives, including reducing inappropriate collection and improving collection techniques.

Outbreak of health care-associated Burkholderia cenocepacia bacteremia and infection attributed to contaminated sterile gel used for central line insertion under ultrasound guidance and other procedures.

BACKGROUND: We report an outbreak of Burkholderia cenocepacia bacteremia and infection in 11 patients predominately in intensive care units caused by contaminated ultrasound gel used in central line insertion and sterile procedures within 4 hospitals across Australia. METHODS: Burkholderia cenocepacia was first identified in the blood culture of a patient from the intensive care unit at the Gold Coast University Hospital on March 26, 2017, with 3 subsequent cases identified by April 7, 2017. The outbreak response team commenced investigative measures. RESULTS: The outbreak investigation identified the point source as contaminated gel packaged in sachets for use within the sterile ultrasound probe cover. In total, 11 patient isolates of B cenocepacia with the same multilocus sequence type were identified within 4 hospitals across Australia. This typing was the same as identified in the contaminated gel isolate with single nucleotide polymorphism-based typing, demonstrating that all linked isolates clustered together. CONCLUSION: Arresting the national point-source outbreak within multiple jurisdictions was critically reliant on a rapid, integrated, and coordinated response and the use of informal professional networks to first identify it. All institutions where the product is used should look back at Burkholderia sp blood culture isolates for speciation to ensure this outbreak is no larger than currently recognized given likely global distribution.

Epidemiological cut-off value of clinical isolates of Burkholderia pseudomallei from Northern Queensland to meropenem, ceftazidime, trimethoprim/sulfamethoxazole and doxycycline by the microbroth dilution method.

OBJECTIVES: Melioidosis is caused by the bacterium Burkholderia pseudomallei. The most common antibiotics used to treat melioidosis in Australia are meropenem, ceftazidime, trimethoprim/sulfamethoxazole (SXT) and doxycycline. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) do not provide standards for assessing the susceptibility of B. pseudomallei for these agents. The International Standards Organisation (ISO) microbroth dilution method is accepted both by the CLSI and EUCAST as the gold standard of antimicrobial susceptibility testing. Many previous studies of the susceptibility of B. pseudomallei used Etest or disk diffusion and presented the results as aggregate data. Etest and disk diffusion methods have not been standardised for B. pseudomallei and aggregate data cannot be used to determine an epidemiological cut-off value (ECOFF). An ECOFF is vital for the setting of clinical breakpoints. METHODS: In this study, minimum inhibitory concentrations (MICs) of meropenem, ceftazidime, SXT and doxycycline were assessed by microbroth dilution for a library of 234 well characterised clinical isolates of B. pseudomallei from Northern Queensland, Australia. RESULTS: The resultant histograms and aggregate data represent the first MIC profile of a large library of B. pseudomallei that has been successfully produced using microbroth dilution. CONCLUSIONS: The MIC profiles can be used to contribute towards a determination of an ECOFF for this species for these agents, which will aid in the setting and refining of clinical breakpoints for the most important antimicrobials used to treat melioidosis.

Paediatric bacteraemias in tropical Australia.

AIM: Bacteraemias in children are an important cause of morbidity and mortality. Knowledge of local epidemiology and trends is important to inform practitioners of likely pathogens in the sick child. This study aimed to determine trends over time in pathogenic organisms causing paediatric bacteraemia in North Queensland and to audit a hospital's blood culture results with respect to contamination rate. METHODS: This was a retrospective review of 8385 blood cultures collected from children attending a tertiary centre in North Queensland over a 10-year period (2001-2010). RESULTS: There were 696 positive blood cultures (8.3%) with 70 different bacterial species detected. Gram-positive and Gram-negative bacteria accounted for 48.6% and 51.4% of isolates, respectively. Overall, bacteraemia accounted for 4.7 per 1000 admissions. The rate of contamination was 60.6% among positive blood cultures and 5.0% for all blood cultures sampled. These results were compared with previous published reports. Notable differences were seen in the frequencies of Salmonella and group A Streptococcus bacteraemias in North Queensland when compared with other reports. There was also a decline in vaccine-preventable infections such as S. pneumoniae and an increasing trend of community-acquired MRSA bacteraemia. CONCLUSION: This study has demonstrated the unique profile of causative pathogens of paediatric bacteraemias in tropical Australia. In light of the increasing prevalence of MRSA, empiric treatment for sepsis for children in this region needs to be reconsidered.

The utility of serial blood film testing for the diagnosis of malaria.

Current guidelines on the diagnosis and exclusion of malaria stipulate that if there is an initial negative result on blood film, multiple blood film preparations should be taken to sufficiently exclude malaria.We looked at a state-wide database of blood results retrospectively for a period of 14 years to identify subjects who had been tested for malaria.Most (93%) of patients were diagnosed on the first blood smear. Almost 7% of patients had an initial negative blood film result but subsequently went on to have a positive result. The majority of patients diagnosed with malaria on the first blood film had Plasmodium falciparum (66%) whilst the majority of patients with an initial negative blood film result were later diagnosed with P. vivax (78%).Most of the subjects in the 7% group were members of the Australian Defence Force and would have received chemoprophylaxis against malaria.The majority of malaria diagnoses are confirmed on a single blood film result. However, a significant proportion of malaria diagnoses would be missed if only one blood film were examined. Currently there is insufficient clinical and epidemiological information to predict which subjects would require one versus three blood film examinations. As such, three blood films should be obtained for patients suspected of having malaria.

Evaluation of a commercially available synthetic RNA lipid enveloped control molecule.

Detection of viral ribonucleic acid with RT PCR is a useful tool for viral detection. One of the drawbacks of this technique is the difficulty in including an internal control molecule to ensure the validity of the extraction and amplification process. In this study the potential usefulness of a novel lipid enveloped commercially available RNA control molecule is investigated. Initial optimisation of the detection assay was performed by amplification of IC (internal control) spiked into PCR water. Thirty-two clinical respiratory samples were spiked with the IC before and after extraction and RT PCR was then performed. Inefficient extraction was simulated. Inhibition of the RT PCR was achieved by serial dilution of heparin sulfate into samples post extraction. No Targets that matched the IC (Internal Control) primers were identified in 32 extracted sputum samples as determined by the absence of non specific amplification curves. The unextracted IC had an increased CT (cycle threshold) value compared to IC that had been extracted. Inefficient extraction was detected by an increased CT. Increasing concentrations of heparin inhibited the PCR in a predictable fashion. The Bioline IC molecule provides a stable RNA IC that has acceptable performance characteristics.

Evaluation of the Remel RapID NF plus rapid biochemical method for identification of Burkholderia pseudomallei.

Typical methods for the identification of Burkholderia pseudomallei colonies produce results in 18 h. The Remel RapID NF Plus kit produces results in 4 h. We used the kit for 190 stored B. pseudomallei isolates and correctly identified 189 of them. This kit produces consistent results for known B. pseudomallei isolates.

The utility of cerebrospinal fluid parameters in the early microbiological assessment of meningitis.

The measurement of cerebrospinal fluid (CSF) protein, glucose, and white cell count (WCC) is an essential part of the initial examination of CSF. The aim of this study was to determine the utility of CSF parameters in assessing the likely aetiological agent. A total of 2290 CSF samples from a 13-year period were retrospectively reviewed. The initial parameters were compared between bacterial, viral, and cryptococcal meningitis and cases where no pathogen was found. A protein concentration of <600 mg/L and a WCC <90 × 10(6)/L were found to be optimal cut-offs for excluding bacterial meningitis. A WCC of <25 × 10(6)/L was found to be optimal for excluding cryptococcal meningitis and a WCC of <10 × 10(6) for excluding viral meningitis. Decreased glucose concentration was found to be a poor indicator of the aetiological agent.