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Background: Elucidating which wildlife species significantly contribute to the maintenance of Ixodes ricinus populations and the enzootic cycles of the pathogens they transmit is imperative in understanding the driving forces behind the emergence of tick-borne diseases. Here, we aimed to quantify the relative contribution of four mustelid species in the life-cycles of I. ricinus and Borrelia burgdorferi (sensu lato) in forested areas and to investigate their role in the transmission of other tick-borne pathogens. Road-killed badgers, pine martens, stone martens and polecats were collected in Belgium and the Netherlands. Their organs and feeding ticks were tested for the presence of tick-borne pathogens., Results: Ixodes hexagonus and I. ricinus were found on half of the screened animals (n = 637). Pine martens had the highest I. ricinus burden, whereas polecats had the highest I. hexagonus burden. We detected DNA from B. burgdorferi (s.l.) and Anaplasma phagocytophilum in organs of all four mustelid species (n = 789), and Neoehrlichia mikurensis DNA was detected in all species, except badgers. DNA from B. miyamotoi was not detected in any of the investigated mustelids. From the 15 larvae of I. ricinus feeding on pine martens (n = 44), only one was positive for B. miyamotoi DNA, and all tested negative for B. burgdorferi (s.l.), N. mikurensis and A. phagocytophilum. The two feeding larvae from the investigated polecats (n = 364) and stone martens (n = 39) were negative for all four pathogens. The infection rate of N. mikurensis was higher in feeding nymphs collected from mustelids compared to questing nymphs, but not for B. burgdorferi (s.l.), B. miyamotoi or A. phagocytophilum., Conclusions: Although all stages of I. ricinus can be found on badgers, polecats, pine and stone martens, their relative contribution to the life-cycle of I. ricinus in forested areas is less than 1%. Consequently, the relative contribution of mustelids to the enzootic cycles of I. ricinus-borne pathogens is negligible, despite the presence of these pathogens in organs and feeding ticks. Interestingly, all four mustelid species carried all stages of I. hexagonus, potentially maintaining enzootic cycles of this tick species apart from the cycle involving hedgehogs as main host species.

Purpose: Diagnostic errors have been attributed to faulty reasoning and cognitive biases, but minimizing errors requires understanding the mechanisms underlying biases. The authors investigated whether salient distracting features (SDFs)-case findings that tend to grab physicians' attention because they are strongly associated with a particular disease, but are indeed unrelated to the problem-misdirect diagnostic reasoning, causing errors., Method: In a 2012 study conducted at Erasmus Medical Centre, Rotterdam, 72 internal medicine residents diagnosed 12 clinical cases (6 simple, 6 complex) in three different formats: without a SDF, with a SDF in the beginning, and with a SDF at the end. In a within-subjects design, each participant solved 2 simple cases and 2 complex cases in each format. Proportions of correct diagnoses in each case type were compared by performing repeated-measures analysis of variance (ANOVA)., Results: There was a significant main effect of SDFs and a significant interaction effect between SDFs and case complexity. The presence of SDFs in the beginning of complex cases caused errors decreasing the proportion of correct diagnoses in comparison both with cases without SDFs (0.18, 95% CI, 0.13-0.23 versus 0.43, 95% CI, 0.35-0.51; P < .001) or with SDFs at the end (0.18, 95% CI, 0.13-0.23 versus 0.36, 95% CI, 0.29-0.43; P < .001). SDFs did not affect performance when presented near the end of cases., Conclusions: SDFs early in a case are apparently an important source of diagnostic errors. Physicians should be aware of the need to overcome their influence.

Background: Psychological research has shown that people tend toward accepting rather than refuting hypotheses. Diagnostic suggestions may evoke such confirmatory tendencies in physicians, which may lead to diagnostic errors., Purpose: This study investigated the influence of a suggested diagnosis on physicians' diagnostic decisions on written clinical cases. It was hypothesized that physicians would tend to go along with the suggestions and therefore would have more difficulty rejecting incorrect suggestions than accepting correct suggestions., Methods: Residents (N = 24) had to accept or reject suggested diagnoses on 6 cases. Three of those suggested diagnoses were correct, and 3 were incorrect., Results: Results showed the mean correct evaluation score on cases with a correct suggested diagnosis (M = 2.21, SD = 0.88) was significantly higher than the score on cases with an incorrect suggested diagnosis (M = 1.42, SD = 0.97), meaning physicians indeed found it easier to accept correct diagnoses than to reject incorrect diagnoses, t(23) = 2.74, p < .05, d = .85, despite equal experience with the diagnoses., Conclusion: These findings indicate that suggested diagnoses may evoke confirmatory tendencies and consequently may lead to diagnostic errors.

Context: Diagnostic errors have been associated with bias in clinical reasoning. Empirical evidence on the cognitive mechanisms underlying biases and effectiveness of educational strategies to counteract them is lacking., Objectives: To investigate whether recent experience with clinical problems provokes availability bias (overestimation of the likelihood of a diagnosis based on the ease with which it comes to mind) resulting in diagnostic errors and whether reflection (structured reanalysis of the case findings) counteracts this bias., Design, Setting, and Participants: Experimental study conducted in 2009 at the Erasmus Medical Centre, Rotterdam, with 18 first-year and 18 second-year internal medicine residents. Participants first evaluated diagnoses of 6 clinical cases (phase 1). Subsequently, they diagnosed 8 different cases through nonanalytical reasoning, 4 of which had findings similar to previously evaluated cases but different diagnoses (phase 2). These 4 cases were subsequently diagnosed again through reflective reasoning (phase 3)., Main Outcome Measures: Mean diagnostic accuracy scores (perfect score, 4.0) on cases solved with or without previous exposure to similar problems through nonanalytical (phase 2) or reflective (phase 3) reasoning and frequency that a potentially biased (ie, phase 1) diagnosis was given., Results: There were no main effects, but there was a significant interaction effect between "years of training" and "recent experiences with similar problems." Results consistent with an availability bias occurred for the second-year residents, who scored lower on the cases similar to those previously encountered (1.55; 95% confidence interval [CI], 1.15-1.96) than on the other cases (2.19; 95% CI, 1.73-2.66; P =.03). This pattern was not seen among the first-year residents (2.03; 95% CI, 1.55-2.51 vs 1.42; 95% CI, 0.92-1.92; P =.046). Second-year residents provided the phase 1 diagnosis more frequently for phase 2 cases they had previously encountered than for those they had not (mean frequency per resident, 1.44; 95% CI, 0.93-1.96 vs 0.72; 95% CI, 0.28-1.17; P =.04). A significant main effect of reasoning mode was found: reflection improved the diagnoses of the similar cases compared with nonanalytical reasoning for the second-year residents (2.03; 95% CI, 1.49-2.57) and the first-year residents (2.31; 95% CI, 1.89-2.73; P =.006)., Conclusion: When faced with cases similar to previous ones and using nonanalytic reasoning, second-year residents made errors consistent with the availability bias. Subsequent application of diagnostic reflection tended to counter this bias; it improved diagnostic accuracy in both first- and second-year residents.