ABSTRACT
Background: Nosocomial bloodstream infections associated with intravascular catheters pose significant financial burden, morbidity, and mortality. There is much debate about whether or not blood cultures should be drawn through central venous catheters, and while guidelines advocate for catheter-drawn cultures when catheter infection is suspected, there is variable practice in this regard. Methods: We performed a retrospective cohort study assessing episodes of positive catheter-drawn blood cultures with concomitant negative percutaneously-drawn cultures in tertiary care hospitals in the United States and Spain. Results: We identified 143 episodes in 122 patients meeting inclusion criteria. Thirty percent of such episodes revealed growth of potential pathogens such as Staphylococcus aureus. Overall, 21% of follow-up percutaneously-drawn blood cultures obtained within 48 hours revealed growth of the same microbe after an episode of positive catheter-drawn blood cultures with negative concomitant percutaneously-drawn cultures (33% when potential pathogens were isolated; 16% when common skin contaminants were isolated). Patients with cultures growing pathogenic organisms were more likely to receive targeted antimicrobial therapy and have their catheters removed sooner. Conclusions: Many episodes of positive catheter-drawn blood cultures with concomitant negative percutaneously-drawn cultures lead to growth from percutaneously-drawn follow-up blood cultures. Thus, such initial discordant results should not be disregarded. Our findings advocate for a nuanced approach to blood culture interpretation, emphasizing the value of catheter-drawn blood cultures in clinical decision making and management.
ABSTRACT
BACKGROUND: Antibiotic resistance is one of the main public health problems worldwide. One key tool to optimize antibiotic prescription is medical training. The aim of this study is to compare the impact of training in infectious diseases on students' knowledge of the antibiotic resistance problem and the rational use of antibiotics. METHODS: We performed a cross-sectional study in the medical school of the University of Navarra. We conducted an anonymous in situ survey of students in each year of training. Data were analyzed grouping the students as follows: GROUP 1: first three years of education, no training in Clinical Microbiology (CM) or in Infectious Diseases (ID); GROUP 2: fourth-year students, training in CM but not ID; GROUP 3: Fifth and sixth-year students who have completed the training in CM and ID. Chi-square test (or Fisher's exact test when appropriate) was performed to evaluate potential associations. Wilcoxon's test was used to compare the median correct answers between groups. We used Spearman's test for correlation between year of training and performance in questionnaire. RESULTS: A total of 994 students respond to the survey, 80.4% of the eligible students. Almost all students who had completed infectious diseases training perceive antibiotic resistance as an important problem in comparison with students who had not completed the formation (99.5% in group 3 vs 94.5% in group 1, p = 0.02). Knowledge of antibiotic stewardship underwent a statistically significant change after training in infectious diseases (from 9.2% in group 1 to 52.2% in group 3, p < 0.001). In the training questions block we also found an increase in the average number of correct answers (21.4% in group 1 vs 44.7% in group 3, p < 0.001). When comparing the results of subgroups 3A and 3B we found a significant loss of knowledge as we moved away from training (49% vs 40.9%, p < 0.001). CONCLUSIONS: The training of medical students is the key to improving both perception and knowledge of infectious diseases. However, we have an opportunity for educational improvement as far as infectious diseases are concerned, regarding both the acquisition of knowledge and its loss as time lapses after training.
