Utility of SARS-CoV-2 rapid antigen testing for patient triage in the emergency department: A clinical implementation study in Melbourne, Australia.

Background: Early, rapid detection of SARS-CoV-2 is essential in healthcare settings in order to implement appropriate infection control precautions and rapidly assign patients to care pathways. Rapid testing methods, such as SARS-CoV-2 rapid antigen testing (RAT) may improve patient care, despite a lower sensitivity than real-time PCR (RT-PCR) testing. Methods: Patients presenting to an Emergency Department (ED) in Melbourne, Australia, were risk-stratified for their likelihood of active COVID-19 infection, and a non-randomised cohort of patients were tested by both Abbott Panbio™ COVID-19 Ag test (RAT) and SARS-CoV-2 RT-PCR. Patients with a positive RAT in the 'At or High Risk' COVID-19 group were moved immediately to a COVID-19 ward rather than waiting for a RT-PCR result. Clinical and laboratory data were assessed to determine test performance characteristics; and length of stay in the ED was compared for the different patient cohorts. Findings: Analysis of 1762 paired RAT/RT-PCR samples demonstrated an overall sensitivity of 75.5% (206/273; 95% CI: 69·9-80·4) for the Abbott Panbio™ COVID-12 Ag test, with specificity of 100% (1489/1489; 95% CI: 99·8-100). Sensitivity improved with increasing risk for COVID-19 infection, from 72·4% (95% CI: 52·8-87·3) in the 'No Risk' cohort to 100% (95% CI: 29·2-100) in the 'High Risk' group. Time in the ED for the 'At/High Risk' group decreased from 421 minutes (IQR: 281, 525) for those with a positive RAT result to 274 minutes (IQR:140, 425) for those with a negative RAT result, p = 0.02. Interpretation: The positive predictive value of a positive RAT in this setting was high, allowing more rapid instigation of COVID-19 care pathways and an improvement in patient flow within the ED. Funding: Royal Melbourne Hospital, Melbourne, Australia.

Targeting antimicrobial stewardship in hospitalised patients with community-acquired pneumonia within 24 h of admission.

BACKGROUND: Over-prescribing in patients with respiratory tract infections is common in Australian hospitals. Senior registrar stewardship input within 24 h of admission in hospitalised patients was assessed to determine if this would improve appropriateness. METHODS: Interventional, non-randomised, case-controlled study over six-month period. Patients diagnosed with pneumonia admitted under General Medicine were discussed at morning handover and assessed by a senior registrar within the first 24 h of admission with real-time stewardship feedback provided. Controls did not receive stewardship advice. Appropriateness of antibiotic use was assessed using Therapeutic Guidelines. RESULTS: In total, 48 patients had an intervention with 49 controls. Ceftriaxone-based regimens were the most commonly prescribed (control 63%; pre-intervention 70%; post-intervention 51%). The senior registrar recommended changes in 26 patients (55%) with 71% uptake of recommendations. The most common recommendation was de-escalation from ceftriaxone-regimen in patients with CORB scores of 0 and 1 (79%; n = 16/20). Post-intervention antibiotic prescribing improved from <5% to 50% in patients with CORB scores of 0 and 1 (p-value <0.05). CONCLUSION: Our results demonstrate that involvement of a senior registrar embedded in the treating team is effective in providing timely advice to influence common hospital over-prescribing in patients with pneumonia. This enhances other antimicrobial stewardship activities such as electronic approval systems and dedicated post-prescribing rounds by Antimicrobial Stewardship team.

Lignin biodegradation and ligninolytic enzyme studies during biopulping of Acacia mangium wood chips by tropical white rot fungi.

White rot fungi are good lignin degraders and have the potential to be used in industry. In the present work, Phellinus sp., Daedalea sp., Trametes versicolor and Pycnoporus coccineus were selected due to their relatively high ligninolytic enzyme activity, and grown on Acacia mangium wood chips under solid state fermentation. Results obtained showed that manganese peroxidase produced is far more compared to lignin peroxidase, suggesting that MnP might be the predominating enzymes causing lignin degradation in Acacia mangium wood chips. Cellulase enzyme assays showed that no significant cellulase activity was detected in the enzyme preparation of T. versicolor and Phellinus sp. This low cellulolytic activity further suggests that these two white rot strains are of more interest in lignin degradation. The results on lignin losses showed 20-30% of lignin breakdown at 60 days of biodegradation. The highest lignin loss was found in Acacia mangium biotreated with T. versicolor after 60 days and recorded 26.9%, corresponding to the percentage of their wood weight loss recorded followed by P. coccineus. In general, lignin degradation was only significant from 20 days onwards. The overall percentage of lignin weight loss was within the range of 1.02-26.90% over the biodegradation periods. Microscopic observations conducted using scanning electron microscope showed that T. versicolor, P. coccineus, Daedalea sp. and Phellinus sp. had caused lignin degradation in Acacia mangium wood chips.