Abstract
The development of a new laboratory-developed norovirus assay provided an opportunity to assess testing patterns, incidence, and outcomes of norovirus among hematopoietic cell transplant (HCT) recipients. Clostridium difficile and norovirus tests from 1,393 HCT recipients were compared in these analyses. In this population of high-risk patients, norovirus appeared to occur seasonally, but testing was infrequent despite a correlation with more severe disease when compared with patients with C difficile infection.