Does next-generation whole genome sequencing identify the direction of norovirus transmission in linked patients?
Phylogenetic analysis excluded a common source of infection in this apparent outbreak. Two of 3 patients on the same ward had closely related viruses, raising the possibility of cross-infection despite protective isolation. Analysis of deep sequencing data enabled us to establish the likely direction of nosocomial transmission.
The results suggest that students need a minimum level of structure in order to profit from problem-based instruction. This structure can be internally provided through prior knowledge available for understanding the new subjects, or offered by the environment in the form of cues of what is relevant and what should be the focus of the activities. If prior knowledge falls short, or if the environment lacks structure, students will turn to their tutors for help and direction. Under those conditions, students who are guided by a subject-matter expert tutor may benefit more than students guided by a non-expert staff tutor or by a student tutor. These findings may explain the widely divergent results of tutor-expertise research.