Diagnostic criteria and core outcome set development for necrotising otitis externa: the COSNOE Delphi consensus study.

OBJECTIVE: Evidence for necrotising otitis externa (NOE) diagnosis and management is limited, and outcome reporting is heterogeneous. International best practice guidelines were used to develop consensus diagnostic criteria and a core outcome set (COS). METHODS: The study was pre-registered on the Core Outcome Measures in Effectiveness Trials (COMET) database. Systematic literature review identified candidate items. Patient-centred items were identified via a qualitative study. Items and their definitions were refined by multidisciplinary stakeholders in a two-round Delphi exercise and subsequent consensus meeting. RESULTS: The final COS incorporates 36 items within 12 themes: Signs and symptoms; Pain; Advanced Disease Indicators; Complications; Survival; Antibiotic regimes and side effects; Patient comorbidities; Non-antibiotic treatments; Patient compliance; Duration and cessation of treatment; Relapse and readmission; Multidisciplinary team management.Consensus diagnostic criteria include 12 items within 6 themes: Signs and symptoms (oedema, otorrhoea, granulation); Pain (otalgia, nocturnal otalgia); Investigations (microbiology [does not have to be positive], histology [malignancy excluded], positive CT and MRI); Persistent symptoms despite local and/or systemic treatment for at least two weeks; At least one risk factor for impaired immune response; Indicators of advanced disease (not obligatory but mut be reported when present at diagnosis). Stakeholders were unanimous that there is no role for secondary, graded, or optional diagnostic items. The consensus meeting identified themes for future research. CONCLUSION: The adoption of consensus-defined diagnostic criteria and COS facilitates standardised research reporting and robust data synthesis. Inclusion of patient and professional perspectives ensures best practice stakeholder engagement.

Changes in antimicrobial resistance in acute otitis media and otitis externa.

OBJECTIVES: Acute otitis media (AOM) and otitis externa (OE) are common ear infections which may warrant antibiotic therapy. For many infections, there is a rise in antimicrobial resistance, which is associated with treatment failure, morbidity, prolonged hospitalisation and mortality. This study aimed to identify longitudinal changes in microbiology and antimicrobial resistance in aural swabs taken from patients with AOM or OE. DESIGN: Retrospective observational analysis. SETTING: Aural samples processed at Manchester Medical Microbiology Partnership Laboratories between January 2008 and December 2018 were analysed to record organism isolated and antimicrobial sensitivity. PARTICIPANTS: Individual aural swabs from 7200 patients. MAIN OUTCOME MEASURES: Changes in the incidence of organisms and antimicrobial resistance between two time periods (2008-2012 and 2013-2018) were compared using the chi-squared test (alpha = 0.05). RESULTS: From 7200 swabs, 2879 (40%) were from children. The most frequently isolated organisms were Staphylococcus aureus (25%), Pseudomonas aeruginosa (24.4%), yeast (9.1%), mixed anaerobes (7.9%) and Haemophilus influenzae (6.1%). In children aged 0-4 years, H. influenzae had particularly high incidence (25%). Overall, the incidence of P. aeruginosa decreased significantly with time (p = 0.05). Isolates displaying resistance to one or more antimicrobial agents increased significantly in number in the second time period for P. aeruginosa (p = 0.04) and H. influenzae (p = 0.03). There was increased resistance to amoxicillin for P. aeruginosa (p = 0.01) and to erythromycin for H. influenzae (p < 0.01). CONCLUSION: Variations in type and frequency of organisms with increasing age likely result from differences in the preponderance of AOM compared to OE in children versus adults. We found increasing antimicrobial resistance for two organisms commonly isolated from AOM and OE infections, suggesting that aspects of current UK treatment practices and national recommendations may need to be revised.

Evaluation of the artus® Prep&Amp UM RT-PCR for detection of SARS-CoV-2 from nasopharyngeal swabs without prior nucleic acid eluate extraction.

Here we describe a retrospective clinical evaluation of the QIAGEN artus® SARS-CoV-2 Prep&Amp UM RT-PCR assay that detects SARS-CoV-2 RNA without the need for a nucleic acid eluate extraction procedure. Using Roche SARS-CoV-2 RT-PCR on the cobas® 8800 platform as a reference standard, a total of 225 confirmed SARS-CoV-2 positive and 320 negative nasopharyngeal swabs in viral transport media, were used to evaluate the artus® assay. Using the RT-PCR cycle threshold as a semi-quantitative marker of viral load, an assessment of over 370,000 SARS-CoV-2 RT-PCR positive results was used in the design of the reference positive specimen cohort. The viral load of all reference positive specimens used in the evaluation was a unique and accurate representation of the range and levels of SARS-CoV-2 positivity observed over a 13-month period of the COVID-19 pandemic. The artus® RT-PCR detects the presence of SARS-CoV-2 RNA, an internal control, and the human RNase P gene to ensure specimen quality. The diagnostic sensitivity of artus® was 92.89% with a specificity of 100%. To assess the analytical sensitivity, a limit of detection was performed using the 1st WHO NIBSC SARS-CoV-2 international standard, recording a 95% LOD of 1.1 × 103 IU/ml. The total invalid rate of specimens was 7.34% due to a lack of detectable RNase P (Ct >35). The artus® SARS-CoV-2 Prep&Amp UM RT-PCR assay is a new rapid RT-PCR assay, which may be considered to produce acceptable levels of diagnostic sensitivity and specificity whilst potentially halving the laboratory processing time.

Routine laboratory surveillance of antimicrobial resistance in community-acquired urinary tract infections adequately informs prescribing policy in England.

OBJECTIVES: To assess whether resistance estimates obtained from sentinel surveillance for antimicrobial resistance (AMR) in community-acquired urinary tract infections (UTIs) differ from routinely collected laboratory community UTI data. METHODS: All patients aged ≥18 years presenting to four sentinel general practices with a suspected UTI, from 13 November 2017 to 12 February 2018, were asked to provide urine specimens for culture and susceptibility. Specimens were processed at the local diagnostic laboratory. Antibiotic susceptibility testing was conducted using automated methods. We calculated the proportion of Escherichia coli isolates that were non-susceptible (according to contemporaneous EUCAST guidelines) to trimethoprim, nitrofurantoin, cefalexin, ciprofloxacin and amoxicillin/clavulanic acid, overall and by age group and sex, and compared this with routine estimates. RESULTS: Sentinel practices submitted 740 eligible specimens. The specimen submission rate had increased by 28 specimens per 1000 population per year (95% CI 21-35). Uropathogens were isolated from 23% (169/740) of specimens; 67% were E. coli (113/169). Non-susceptibility of E. coli to trimethoprim was 28.2% (95% CI 20.2-37.7) on sentinel surveillance (33.4%; 95% CI 29.5-37.6 on routine data) and to nitrofurantoin was 0.9% (95% CI 0-5.7) (1.5%; 95% CI 0.7-3.0 on routine data). CONCLUSIONS: Routine laboratory data resulted in a small overestimation in resistance (although the difference was not statistically significant) and our findings suggest that it provides an adequate estimate of non-susceptibility to key antimicrobials in community-acquired UTIs in England. This study does not support the need for ongoing local sentinel surveillance.

Invasive zygomycosis in hematopoietic stem cell transplant recipients receiving voriconazole prophylaxis.

We report 4 cases of invasive zygomycosis in hematopoietic stem cell transplant recipients, all occurring after May 2003, when voriconazole began to be used as antifungal prophylaxis. No cases of zygomycosis had been detected in this population in the 3 years prior to May 2003. All 4 patients were receiving immunosuppressive therapy for presumed graft-versus-host disease. Profoundly immunosuppressed patients receiving voriconazole prophylaxis remain at risk for less-common pathogens that are intrinsically resistant to this agent.

Clade-specific flucytosine resistance is due to a single nucleotide change in the FUR1 gene of Candida albicans.

Population studies have indicated that natural resistance to flucytosine (5FC) in Candida albicans is limited to one of the five major clades, clade I. In addition, while 73% of clade I isolates are less susceptible to 5FC (MIC >/= 0.5 microg/ml), only 2% of non-clade I isolates are less susceptible. In order to determine the genetic basis for this clade-specific resistance, we sequenced two genes involved in the metabolism of 5FC that had previously been linked to resistance (cytosine deaminase and uracil phosphoribosyltransferase), in 48 isolates representative of all clades. Our results demonstrate that a single nucleotide change from cytosine to thymine at position 301 in the uracil phosphoribosyltransferase gene (FUR1) of C. albicans is responsible for 5FC resistance. The mutant allele was found only in group I isolates. The 5FC MICs for strains without copies of the mutant allele were almost exclusively /=0.5 microg/ml, and those for strains with two copies of the mutant allele were >/=16 microg/ml. Thus, the two alleles were codominant. The presence of this allele is responsible for clade I-specific resistance to 5FC within the C. albicans population and thus by inference is likely to be the major underlying 5FC resistance mechanism in C. albicans. This represents the first description of the genetic mutation responsible for 5FC resistance.