Clustering of Gastrointestinal Microorganisms in Human Stool Samples from Ghana.

The study was conducted to identify cluster patterns of enteric microorganisms with potential etiological relevance for infectious gastroenteritis in stool samples of individuals from Ghana, which is a known high-endemicity setting for infectious gastroenteritis. These patterns were compared to previous observations with specimens from Colombian indigenous people in order to assess potentially stable clustering for temporally and spatially distinct populations from high-endemicity regions. By doing so, the study aimed to identify stable clusters as markers of microbial interaction with potential importance for etiological relevance assignment in cases of multiple enteric pathogen detections. Stool samples from 1569 Ghanaian individuals (875 from HIV patients, 30 from HIV-negative control adult patients, and 644 from children < 2 years of age) were assessed for enteric microorganisms by applying real-time PCR. As a result, nucleic acids of bacterial microorganisms were most frequently detected, followed by protozoa, microsporidia, and helminths. Interestingly, the cluster assessment confirmed interaction patterns known from the previous analysis with Colombian indigenous people, demonstrating a high likelihood of Blastocystis hominis for clustering with other microorganisms and a prominent, potentially mediating role of Dientamoeba fragilis for microbial interactions within the clusters. In conclusion, the assessment confirmed conserved clustering of enteric microorganisms with potential etiological relevance for human infectious gastroenteritis over geographically distinct high-endemicity settings. Furthermore, the composition of abundant microorganisms is more important than regional factors for the determination of the interplay of enteric microorganisms in the human gut. Thereby, some microbial pathogens and commensals seem more susceptible to a changing microbial composition in the human gut than others.

Improved Learning Gain in Medical Students by Using Animated Whiteboard-Videos in Comparison to Textbooks in Surgery.

BACKGROUND: Animated videos have become popular in teaching medical students, although there is a certain lack of evidence concerning its efficacy. Surgery seems to be an ideal field for its application, since animations are very helpful to understand anatomic structures and complex procedures. The aim of this study was to investigate the effects of animated videos compared to textbooks on learning gain. METHODS: A prospective 2-arm cohort study with 5th-year medical students was conducted during their 2-week surgical training module. The initial cohort of students received textbook sections on 3 major topics in visceral surgery as learning medium (text cohort). During the following semester, the second cohort of students received 3 animated whiteboard videos (animated videos) containing equivalent content (video cohort). All participants completed a multiple-choice test consisting of 15 questions on the learning content at baseline (pre-test) and after the learning period (post-test) and answered an additional evaluation questionnaire. RESULTS: Both cohorts were similar in their descriptive data and demonstrated significant learning gain during the 2-week learning period. The video cohort achieved better results (80% vs 73% correct answers; P = .028) and a higher learning gain (17% vs 11%; P = .034) in the post-test compared to the text cohort. The estimated learning time was longer in the video cohort (62 min vs 37 min; P < .001) and watching the videos resulted in higher learning gain (21% vs 6%; P < .001). Subgroups with higher learning gain by video learning were female gender (20% vs 11%; P = .040), native German speakers (18% vs 11%; P = .009), students without prior surgical experience (19% vs 12%; P = .033) and those undecided concerning a surgical career (22% vs 9%; P = .020). Interestingly, "low digital orientation" students benefited from videos (22% vs 13%; P = .021), whereas "high digital orientation" students did not. CONCLUSIONS: Animated videos increase medical students' learning gain and interest in surgery.

Collider Bias Assessment in Colombian Indigenous Wiwa and Kogui Populations with Chronic Gastroenteric Disorder of Likely Infectious Etiology Suggests Complex Microbial Interactions Rather Than Clear Assignments of Etiological Relevance.

Multiple microbial detections in stool samples of indigenous individuals suffering from chronic gastroenteric disorder of a likely infectious origin, characterized by recurring diarrhea of variable intensity, in the rural north-east of Colombia are common findings, making the assignment of etiological relevance to individual pathogens challenging. In a population of 773 indigenous people from either the tribe Wiwa or Kogui, collider bias analysis was conducted comprising 32 assessed microorganisms including 10 bacteria (Aeromonas spp., Campylobacter spp., enteroaggregative Escherichia coli (EAEC), enteropathogenic Escherichia coli (EPEC), enterotoxigenic Escherichia coli (ETEC), Salmonella spp., Shiga toxin-producing Escherichia coli (STEC), Shigella spp./enteroinvasive Escherichia coli (EIEC), Tropheryma whipplei and Yersinia spp.), 11 protozoa (Blastocystis spp., Cryptosporidium spp., Cyclospora spp., Dientamoeba fragilis, Entamoeba coli, Entamoeba bangladeshi/dispar/histolytica/moshkovskii complex, Entamoeba histolytica, Endolimax nana, Giardia duodenalis, Iodamoeba buetschlii and Pentatrichomonas hominis), 8 helminths (Ascaris spp., Enterobius vermicularis, Hymenolepis spp., Necator americanus, Schistosoma spp., Strongyloides spp., Taenia spp. and Trichuris spp.), microsporidia (Encephalocytozoon spp.) and fungal elements (microscopically observed conidia and pseudoconidia). The main results indicated that negative associations potentially pointing towards collider bias were infrequent events (n = 14), while positive associations indicating increased likelihood of co-occurrence of microorganisms quantitatively dominated (n = 88). Microorganisms showing the most frequent negative associations were EPEC (n = 6) and Blastocystis spp. (n = 3), while positive associations were most common for Trichuris spp. (n = 16), Dientamoeba fragilis (n = 15), Shigella spp./EIEC (n = 12), Ascaris spp. (n = 11) and Blastocystis spp. (n = 10). Of note, positive associations quantitively dominated for Blastocystis spp. In conclusion, collider bias assessment did not allow clear-cut assignment of etiological relevance for detected enteric microorganisms within the assessed Colombian indigenous population. Instead, the results suggested complex microbial interactions with potential summative effects. Future studies applying alternative biostatistical approaches should be considered to further delineate respective interactions.

Chagas Disease: Comparison of Therapy with Nifurtimox and Benznidazole in Indigenous Communities in Colombia.

Background: For indigenous people in Colombia, high infection rates with Chagas disease (CD) are known. Methods: In 2018 and 2020, nine villages were screened for CD. CD-positive patients could enter a drug observed treatment. While, in 2018, Benznidazole (BNZ) was provided as the first-line drug by the government, nifurtimox (NFX) was administered in 2020. Results: Of 121 individuals treated with BNZ, 79 (65%) suffered from at least one adverse event (AE). Of 115 treated with NFX, at least one AE occurred in 96 (84%) patients. In 69% of BNZ cases, the side effects did not last longer than one day; this applied to 31% of NFX cases. Excluding extreme outlier values, average duration of AEs differed highly significantly: BNZ (M = 0.7, SD = 1.4) and NFX (M = 1.7, SD = 1.5, p < 0.001). Using an intensity scale, AEs were highly significantly more severe for NFX (M = 2.1, SD = 0.58) compared to BZN (M = 1.1, SD = 0.38), p < 0.001. When analyzing the duration in relation to the intensity, the burden of AEs caused by NFX was significantly more pronounced. Dropouts (n = 2) due to AEs were in the NFX-group only. Conclusions: Side effects caused by BNZ were significantly fewer, as well as milder, shorter in duration, and more easily treatable, compared to NFX.

[Repetitio est mater studiorum-implementation of ENT cases in case-based e-learning]. / Repetitio est mater studiorum ­ Implementierung von HNO-Fällen in fallbasiertes E-Learning.

BACKGROUND: German university otorhinolaryngology has a need for digital teaching content. Case-based e­learning represents a digital teaching methodology. The data on student use of case-based e­learning in university teaching of ENT medicine are limited. OBJECTIVE: The aim of this work was to determine the extent to which voluntary case-based e­learning is used by otolaryngology students and what influence the quality of the e­learning has on motivation to use e­learning and on the interest in otolaryngology. MATERIALS AND METHODS: Fifteen voluntary e­learning cases were created based on the content of the ENT lecture in the winter semester 2022/2023. Subsequently, a descriptive evaluation of the usage statistics of the cases of 157 students was conducted. Likewise, an evaluation of the quality of the e­learning as well as the motivation to complete it and the interest in otorhinolaryngology was carried out using a voluntary questionnaire. RESULTS: Voluntary case-based e­learning was used to varying degrees by 66% of the students. The quality of e­learning correlated significantly with the motivation and the interest in otolaryngology. CONCLUSION: The teaching content of otorhinolaryngology can be implemented sufficiently in case-based e­learning and is characterized by satisfactory student acceptance. Integration should be accomplished in a high-quality manner to increase motivation and interest in otorhinolaryngology.

Gastrointestinal Pathogens in Multi-Infected Individuals: A Cluster Analysis of Interaction.

Indigenous people live in remote areas of Colombia. Multiple infections with bacteria, protozoa and/or helminths are common, as well as colonization in various forms. This study focused on the question of whether and to what extent various pathogens interact with each other. Therefore, a mathematical approach was retrospectively applied to PCR-based data of 244 stool samples, collected in two datasets. A stable cluster solution of the pathogens assessed was determined, and a unique configuration between Blastocystis hominis/Campylobacter spp./Giardia lamblia forming cluster 1 and Dientaemoeba fragilis was verified. A pathogen density-dependent interplay appeared between the B. hominis/Campylobacter spp./G. lamblia cluster, D. fragilis and Ascaris lumbricoides. The applied mathematical approach demonstrated that co-infections with parasites of questionable pathological relevance such as B. hominis and D. fragilis can be of diagnostic relevance due to their ability to promote or repress other pathogens. With the increasing availability of highly sensitive multiplexed molecular diagnostic approaches even in resource-limited settings, where multiple colonization of infection events with enteric pathogens in parallel are common, the importance of interpreting whole pathogen patterns rather than just individual pathogen detection may become more and more relevant.

A novel approach to microsurgical teaching in head and neck surgery leveraging modern 3D technologies.

The anatomically complex and often spatially restricted conditions of anastomosis in the head and neck region cannot be adequately reproduced by training exercises on current ex vivo or small animal models. With the development of a Realistic Anatomical Condition Experience (RACE) model, complex spatial-anatomical surgical areas and the associated intraoperative complexities could be transferred into a realistic training situation in head and neck surgery. The RACE model is based on a stereolithography file generated by intraoperative use of a three-dimensional surface scanner after neck dissection and before microvascular anastomosis. Modelling of the acquired STL file using three-dimensional processing software led to the model's final design. As a result, we have successfully created an economical, sustainable and realistic model for microsurgical education and provide a step-by-step workflow that can be used in surgical and general medical education to replicate and establish comparable models. We provide an open source stereolithography file of the head-and-neck RACE model for printing for educational purposes. Once implemented in other fields of surgery and general medicine, RACE models could mark a shift in medical education as a whole, away from traditional teaching principles and towards the use of realistic and individualised simulators.

Tablet-based versus presentation-based seminars in radiology: Effects of student digital affinity and teacher charisma on didactic quality.

Aims: Tablets are being adopted as teaching medium in medical education more frequently. Here we compared two teaching formats in a radiology seminar using a tablet-based student-centred approach guided by teachers and traditional presentation-based, teacher-centred instruction. The aim was to investigate the effects on academic performance, estimated learning gain, didactic quality, as well as how teacher charisma and student digital affinity influence these elements. Methods: Data from 366 students were collected. Student digital affinity, didactic quality of, and overall satisfaction with the seminars were rated for each teaching format over three semesters, whereby in the last semester, students additionally estimated their learning gain, took a knowledge and image interpretation test, and rated teacher charisma. Results: The tablet-based seminars yielded significantly higher ratings for didactic quality and overall satisfaction. However, the presentation-based seminars proved superior with respect to academic performance as well as estimated learning gain. When employing tablets, teacher charisma correlated with estimated learning gain, and digital affinity affected didactic quality. Additionally, good seminar organization, comprehensible learning objectives, and optimal variation of learning activities were identified as important factors. Conclusion: This study suggests a complex interplay of various factors concerning teachers, students, and didactics that can be assessed and improved to assure the successful curricular implementation of tablets. Of note, tablet integration and thereby active engagement of students with imaging analysis skills does not automatically result in greater declarative knowledge. Nevertheless, understanding the complexities of structuring and delivering tablet-based, teacher-guided instruction is essential to creating meaningful educational experiences.

Item format statistics and readability of extended matching questions as an effective tool to assess medical students.

Testing based on multiple choice questions (MCQ) is one of the most established forms of assessment, not only in the medical field. Extended matching questions (EMQ) represent a specific type of MCQ designed to require higher levels of cognition, such as problem-solving. The purpose of this evaluation was to assess the suitability and efficiency of EMQ as an assessment method. EMQ were incorporated into the end-of-semester examination in internal medicine, in which 154 students participated, and compared with three established MCQ types. Item and examination quality were investigated, as well as readability and processing time. EMQ were slightly more difficult to score; however, both item discrimination and discrimination index were higher when compared to other item types. EMQ were found to be significantly longer and required more processing time, but readability was improved. Students judged EMQ as clearly challenging, but attributed significantly higher clinical relevance when compared to established MCQ formats. Using the Spearman-Brown prediction, only ten EMQ items would be needed to reproduce the Cronbach's alpha value of 0.75 attained for the overall examination. EMQ proved to be both efficient and suitable when assessing medical students, demonstrating powerful characteristics of reliability. Their expanded use in favor of common MCQ could save examination time without losing out on statistical quality.

Quantifying teaching quality in medical education: The impact of learning gain calculation.

BACKGROUND: Student performance is a mirror of teaching quality. The pre-/post-test design allows a pragmatic approach to comparing the effects of interventions. However, the calculation of current knowledge gain scores introduces varying degrees of distortion. Here we present a new metric employing a linear weighting coefficient to reduce skewness on outcome interpretation. METHODS: We compared and contrasted a number of common scores (raw and relative gain scores) with our new method on two datasets, one simulated and the other empirical from a previous intervention study (n = 180) employing a pre-/post-test design. RESULTS: The outcomes of the common scores were clearly different, demonstrating a significant dependency on pre-test scores. Only the new metric revealed a linear relationship to the knowledge baseline, was less skewed on the upper or lower extremes, and proved well suited to allow the calculation of negative learning gains. Employing the empirical dataset, the new method also confirmed the interaction effect of teaching formats with specific subgroups of learner characteristics. CONCLUSION: This work introduces a new weighted metric enabling meaningful comparisons between interventions based on a linear transformation. This method will form the basis to intertwine the calculation of test performance closely with the outcome of learning as an important factor reflecting teaching quality and efficacy. Its regular use can improve the transparency of teaching activities and outcomes, contribute to forming rounded judgements of students' acquisition of knowledge and skills and enable valuable feedforward to develop and enhance curricular concepts.

Students' perception of three-dimensionally printed teeth in endodontic training.

INTRODUCTION: In endodontic education, there is a need for thorough training prior to students embarking on clinical treatment. The aim of this study was to use three-dimensional printing technology to create a new model and to compare its suitability for training purposes with resin blocks and extracted teeth. MATERIALS AND METHODS: Multi-jet-modelling (MJM) produced the 3D model replicating a common difficulty in root-canal morphology. An evaluation study comprising 88 students was run in the sixth semester (summer 2018 and winter 2018/2019). A new questionnaire assessed students' perception of training models and educational environment. Welch's t-test analysed significant differences. RESULTS: The most pronounced differences between models were noted when rating material hardness, radiopacity, root-canal configuration and suitability for practising. Students estimated their learning outcome as greater with 3D-printed teeth compared to resin blocks. Three-dimensionally printed teeth received significantly lower ratings with regard to enthusiasm, the learning of fine motor skills and spatial awareness, when compared to human teeth (p ≤ .001). However, 3D-printed teeth were appreciated for additional benefits, such as their cleanliness, availability and standardisation of training opportunities with complex root-canal configurations. CONCLUSION: Students preferred extracted human teeth to 3D-printed teeth with respect to their physical characteristics and training experience. However, educational advantages may compensate for the shortcomings. The new questionnaire proved both adequate and accurate to assess the models and educational environment in endodontic training. The new 3D-printed teeth enhanced the learning opportunities.

Psychometric Properties and Calibration of the SPOREEM (Students' Perception of the Operating Room Educational Environment Measure).

OBJECTIVE: The experience in the operating room is considered as a crucial element affecting medical students' satisfaction with workplace-based training in surgery. We developed the "Students' Perception of the Operating Room Educational Environment Measure" (SPOREEM) and applied the approach of Item Response Theory to improve accuracy of its measurement. DESIGN: Psychometric analysis determined the factorial structure. Using Item Response Theory, item thresholds were calculated on response option levels. Sum scores in the factors were then computed using calibrated unit weights. SETTING: One hundred medical students from the University Medical Center in Goettingen, Germany, enrolled in a one-week surgery rotation completed the SPOREEM. RESULTS: The final 19-item questionnaire resulted in 3 factors: "Learning support and inclusion" (1), "Workplace atmosphere" (2), and "Experience of emotional stress" (3). Item calibration resulted in refinement of sum scores in the factors. Male students significantly rated factor 1 more positively. Factor 2 was perceived to a similar degree in all 3 surgical disciplines involved. Factor 3 was rated lower by those students planning a surgical field of postgraduate training. CONCLUSIONS: We developed a valid, reliable, and feasible tool to assess the overall educational climate of undergraduate training in the OR. Calibration of items refined the measurement.

High Prevalence of Intestinal Pathogens in Indigenous in Colombia.

BACKGROUND: Intestinal infections remain a major public health burden in developing countries. Due to social, ecological, environmental, and cultural conditions, Indigenous peoples in Colombia are at particularly high risk. MATERIALS: 137 stool samples were analyzed by microscopy and real-time-Polymerase Chain Reaction (RT-PCR), targeting protozoan parasites (Giardia intestinalis, Entamoeba histolytica, Cryptosporidium spp., and Cyclospora cayetanensis), bacteria (Campylobacter jejuni, Salmonella spp., Shigella ssp./enteroinvasive E. coli (EIEC), Yersinia spp., enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli ( EPEC), enterotoxin-producing E. coli (ETEC), enteroaggregative E. coli (EAEC), and Tropheryma whipplei), and helminths (Necator americanus, Strongyloides stercoralis, Ascaris lumbricoides, Ancylostoma spp., Trichuris. trichiura, Taenia spp., Hymenolepis nana, Enterobius vermicularis, and Schistosoma spp.). Microscopy found additional cases of helminth infections. RESULTS: At least one pathogen was detected in 93% of the samples. The overall results revealed protozoa in 79%, helminths in 69%, and bacteria in 41%. G. intestinalis (48%), Necator/hookworm (27%), and EAEC (68%) were the most common in each group. Noteworthy, T. whipplei was positive in 7% and T. trichirua in 23% of the samples. A significant association of one infection promoting the other was determined for G. intestinalis and C. jejuni, helminth infections, and EIEC. CONCLUSIONS: The results illustrate the high burden of gastrointestinal pathogens among Indigenous peoples compared to other developing countries. Countermeasures are urgently required.

Digital Affinity in Medical Students Influences Learning Outcome: A Cluster Analytical Design Comparing Vodcast With Traditional Lecture.

BACKGROUND/OBJECTIVE: Undergraduate medical education still relies on lectures as the core teaching activity. However, e-learning and new media have begun to augment learning and information gathering over the last few years. The aim of this study was to investigate the effect of 2 teaching formats in surgical education, a classic lecture and a video podcast (vodcast), on knowledge gain, in particular with respect to the participants' characteristics and preferences. DESIGN: A prospective study was conducted over 2 consecutive semesters. A traditional lecture on goitre was given to the first of the 2 semesters and replaced by a matching vodcast made available to the second. An untaught subject (cholelithiasis) served as control. Knowledge gain was calculated as the difference in point scores between entry and mid-module examinations. Furthermore, participants completed a postintervention survey, in which they specifically rated their digital affinity and learning preferences. A cluster analysis was conducted pooling both semesters to evaluate differences between individuals affecting their performance. RESULTS: Both teaching formats resulted in a significant knowledge gain. Two clusters could be identified across both semesters: Cluster 2 (Digital natives) proved to be significantly different from Cluster 1 (Traditional) with respect to the 4 variables: "technically interested," the "use of smartphones," "activity in social networks," and "reading in digital formats." The knowledge gain differences between formats for students in the "Traditional" cluster were statistically insignificant. However, students in the cluster "Digital natives" performed significantly worse when exposed to the lecture format. CONCLUSIONS: Cluster analysis revealed that the students with an obvious affinity to information communication technology were found to be at a significant disadvantage in the lecture. In future, we recommend offering some form of pretest to determine an individual's profile and empower students to plan their learning activities accordingly.

Assessment of Health-Related Quality of Life after TBI: Comparison of a Disease-Specific (QOLIBRI) with a Generic (SF-36) Instrument.

Psychosocial, emotional, and physical problems can emerge after traumatic brain injury (TBI), potentially impacting health-related quality of life (HRQoL). Until now, however, neither the discriminatory power of disease-specific (QOLIBRI) and generic (SF-36) HRQoL nor their correlates have been compared in detail. These aspects as well as some psychometric item characteristics were studied in a sample of 795 TBI survivors. The Shannon H (') index absolute informativity, as an indicator of an instrument's power to differentiate between individuals within a specific group or health state, was investigated. Psychometric performance of the two instruments was predominantly good, generally higher, and more homogenous for the QOLIBRI than for the SF-36 subscales. Notably, the SF-36 "Role Physical," "Role Emotional," and "Social Functioning" subscales showed less satisfactory discriminatory power than all other dimensions or the sum scores of both instruments. The absolute informativity of disease-specific as well as generic HRQoL instruments concerning the different groups defined by different correlates differed significantly. When the focus is on how a certain subscale or sum score differentiates between individuals in one specific dimension/health state, the QOLIBRI can be recommended as the preferable instrument.