K.N.P. Kumar

Frequency and significance of indeterminate and borderline Quantiferon Gold TB IGRA Results

The Quantiferon Gold test is one of two commercially available tuberculosis (TB) interferon-γ release assays (IGRAs) recommended for the diagnosis of latent TB infection [1]. A Quantiferon Gold test is considered positive if the result is ≥0.35 IU·mL−1 [2]. However, longitudinal studies have shown that a significant number of test reversions and conversions occur if results just above or below this threshold are repeated [3, 4]. This variation may be due to random chance or other factors such as test-related errors, differences in absolute lymphocyte numbers and within-subject variability of the interferon-γ response [5, 6]. The high proportion of conversions and reversions around the 0.35 IU·mL−1 cut-off has led some to suggest that a borderline or equivocal range should be used [7], as this avoids treatment of individuals who do not have a ‘stable’ positive result, as well as failure to treat those just below the 0.35 threshold who would convert to a positive result if the test were repeated [6]. Borderline and equivocal results for the Quantiferon Gold test are common and repeated borderline tests often change http://ow.ly/PDDZ30fqJ1c

Medical students without borders: The value of undergraduate placements abroad

14 the upper-limits (UL) and lower-limits (LL) of pass-marks and fail-rates generate negligible changes in cut-scores (1–2%). We agree with Tavakol & Dennick’s conclusions and we have developed a substantially modified-Hofstee (MH) method that obviates subjective judgements. In the MH protocol, the UL and LL for fail-rates are set at 100% and 0% of the cohort, respectively, i.e. potentially all candidates could fail or pass, avoiding arbitrary pass/fail quotas. The LL for the pass-mark is also set at 0%, avoiding an arbitrary boundary for this value. The UL for the pass-mark is standard set an absolute percentage below the median percentage mark of the cohort (based on trials on historical data). The rationale for this is that cohort performance is an objective measure of exam difficulty when the cohort is sufficiently large and its selection is consistent year-on-year (as is likely for selection of medical students). (Others have similarly argued for using cohort data for setting borderlines (Cohen-Schotanus & van der Vleuten, 2010). A diagonal is drawn for the UL pass-mark on the X-axis to the UL of fails (100%) on the Y-axis; the intersection with the cumulative frequency curve of students’ marks gives the actual pass-mark. We applied the MH protocol to historical data of 49 summative assessments sat by cohorts of 4240 year 1–3 medical students over five years. The range of pass-marks generated by MH was 47%–60% (median 57%). We further examined the effect on 15 assessments of raising the UL of the pass-mark by 10%; this increased the cut-scores by 5.4%–8.5% (median 6.6%), which is substantially greater than reported by Tavakol & Dennick for CH. Furthermore, if the diagonal does not intersect with the frequency curve, this indicates that all students pass. Whilst Anghoff/Ebel are appropriate for ‘‘high-stakes’’, broad-based clinical exams, they may be impractical for multiple, subject-specific exams, where assembling and ensuring consistent operation of multiple panels of experts is not feasible. In such circumstances, the MH protocol may provide a viable and robust alternative for credible standard setting.

Asymptomatic pyogenic liver abscesses secondary to Fusobacterium nucleatum and Streptococcus vestibularis in an immunocompetent patient

A 66-year-old male patient presented with symptoms and signs of L4/5 radiculopathy. He was found to be anaemic with elevated inflammatory markers and deranged hepatic enzymes. Imaging revealed lumbar canal stenosis and the presence of pyogenic liver abscesses from which Fusobacterium nucleatum and Streptococcus vestibularis were isolated. The hepatic abscesses were attributed to asymptomatic diverticular perforation. Multiple coexisting incidental infections were discovered, including oesophageal candidiasis, Helicobacter pylori, stool cultures positive for Strongyloides stercoralis, and sputum cultures positive for Enterobacter cloacae, Escherichia coli and Mycobacterium avium. Extensive investigations for possible underlying immunosuppression were negative.

Expanding horizons: increasing undergraduate exposure to tomorrow's specialties.

cians. Recent research indicates that over half of US medical schools now staff SRFCs, which collectively serve tens of thousands of patients yearly (Simpson & Long 2007). In single center surveys, students have endorsed SRFCs as valuable educational experiences that positively influence their attitude toward working with underserved populations (Smith et al. 2012). Yet no surveys to date have investigated SRFCs integration with formal curricula or the complementary curricula that students themselves develop. Medical students have gained the foundations necessary to care for patients during their preclinical years through classroom instruction, shadowing clinicians, and standardized patient experiences. These formal curricula typically follow the model of skill acquisition outlined by the Dreyfus and Dreyfus model, as students gain responsibilities in accordance with their developmental stages (Dreyfus & Dreyfus 1980). This model has been especially important in medicine, where learners invariably begin as novices whose practice may cause inadvertent iatrogenic harm. In our recent experience, a complementary curriculum developed by upperclassmen at our institution offered first-year medical students a guide to problem focused history taking, medical heuristics, and therapeutic options. Though well intentioned, these guides could encourage novices to perform intern level skills prior to receiving formal instruction. While early skills-training has been successful, supervision and proper definition of roles will be crucial to the provision of ethical patient care. Future studies should investigate the integration of formal curricula with SRFCs, the complementary curricula that students themselves develop, and the impact of these interventions at SRFCs.

A curious case of cholestasis: oral terbinafine associated with cholestatic jaundice and subsequent erythema nodosum

Terbinafine is a commonly prescribed antifungal agent used in the treatment oftrichophytic onychomycosis and chronic cutaneous mycosis that are resistant to other treatments. This case report highlights a rarely documented but important adverse hepatic reaction that was caused by the use of oral terbinafine. A woman in her thirties presented with a 3-week history of jaundice, malaise, itching, nausea, decreased appetite, weight loss, dark orange urine and intermittent non-radiating epigastric pain. She had recently finished a 3-week course of oral terbinafine for a fungal nail infection. Liver biopsy findings were consistent with chronic active hepatitis secondary to a drug reaction. A few days after initial presentation, the patient developed erythema nodosum. Delayed development of erythema nodosum secondary to terbinafine could not be excluded.