TY - JOUR A1 - Elias, Johannes A1 - Heuschmann, Peter U. A1 - Schmitt, Corinna A1 - Eckhardt, Frithjof A1 - Boehm, Hartmut A1 - Maier, Sebastian A1 - Kolb-Mäurer, Annette A1 - Riedmiller, Hubertus A1 - Müllges, Wolfgang A1 - Weisser, Christoph A1 - Wunder, Christian A1 - Frosch, Matthias A1 - Vogel, Ulrich T1 - Prevalence dependent calibration of a predictive model for nasal carriage of methicillin-resistant Staphylococcus aureus JF - BMC Infectious Diseases N2 - Background Published models predicting nasal colonization with Methicillin-resistant Staphylococcus aureus among hospital admissions predominantly focus on separation of carriers from non-carriers and are frequently evaluated using measures of discrimination. In contrast, accurate estimation of carriage probability, which may inform decisions regarding treatment and infection control, is rarely assessed. Furthermore, no published models adjust for MRSA prevalence. Methods Using logistic regression, a scoring system (values from 0 to 200) predicting nasal carriage of MRSA was created using a derivation cohort of 3091 individuals admitted to a European tertiary referral center between July 2007 and March 2008. The expected positive predictive value of a rapid diagnostic test (GeneOhm, Becton & Dickinson Co.) was modeled using non-linear regression according to score. Models were validated on a second cohort from the same hospital consisting of 2043 patients admitted between August 2008 and January 2012. Our suggested correction score for prevalence was proportional to the log-transformed odds ratio between cohorts. Calibration before and after correction, i.e. accurate classification into arbitrary strata, was assessed with the Hosmer-Lemeshow-Test. Results Treating culture as reference, the rapid diagnostic test had positive predictive values of 64.8% and 54.0% in derivation and internal validation corhorts with prevalences of 2.3% and 1.7%, respectively. In addition to low prevalence, low positive predictive values were due to high proportion (> 66%) of mecA-negative Staphylococcus aureus among false positive results. Age, nursing home residence, admission through the medical emergency department, and ICD-10-GM admission diagnoses starting with “A” or “J” were associated with MRSA carriage and were thus included in the scoring system, which showed good calibration in predicting probability of carriage and the rapid diagnostic test’s expected positive predictive value. Calibration for both probability of carriage and expected positive predictive value in the internal validation cohort was improved by applying the correction score. Conclusions Given a set of patient parameters, the presented models accurately predict a) probability of nasal carriage of MRSA and b) a rapid diagnostic test’s expected positive predictive value. While the former can inform decisions regarding empiric antibiotic treatment and infection control, the latter can influence choice of screening method. KW - Methicillin-resistant staphylococcus aureus KW - Infection control KW - Clinical prediction rule KW - Predictive value of tests KW - False positive reactions KW - Calibration Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96091 UR - http://www.biomedcentral.com/1471-2334/13/111 ER - TY - JOUR A1 - Strobel, Katharina A1 - Sickenberger, Christina A1 - Schoen, Christoph A1 - Kneitz, Hermann A1 - Kolb-Mäurer, Annette A1 - Goebeler, Matthias T1 - Diagnosis and therapy of Mycobacterium marinum: a single-center 21-year retrospective analysis JF - Journal der Deutschen Dermatologischen Gesellschaft N2 - Background and Objectives In Europe, infections with Mycobacterium (M.) marinum are rare. We conducted a retrospective single-center study to assess the clinical spectrum of M. marinum infection and its diagnosis, treatment and outcome under real-world conditions. Patients and Methods Eighteen patients presenting with M. marinum infections between 1998 and 2018 were identified in the data warehouse of the University Hospital Würzburg and considered for detailed analysis. Results Twelve patients reported aquatic exposure. In 16/18 cases the upper extremities were affected. No invasive infections were detected. Mean time to diagnosis was 15 weeks. Histology revealed granulomatous inflammation in 14 patients while mycobacterial cultures were positive for M. marinum in 16 cases. Most patients received antibiotic monotherapy (14/18) while combination therapy was administered in four cases. Treatment (with a median duration of 10 weeks) was successful in 13 patients. Five patients were lost to follow-up. Conclusions Our retrospective analysis of M. marinum infections at a German tertiary referral center revealed a considerable diagnostic delay and the relevance of microbiological culture, PCR and histology for diagnosis. Monotherapy with clarithromycin (rather than doxycycline) appeared as a reasonable treatment option while immunosuppressed or -compromised patients and those with extended disease received combination therapy. KW - Mycobacterium marinum KW - diagnosis KW - therapy Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318428 VL - 20 IS - 9 SP - 1211 EP - 1218 ER -