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Background. A retrospective study of the clinical, epidemiologic, and virologic features of norovirus gastroenteritis in 12 adult allogeneic hematopoietic stem cell transplant (HSCT) recipients. Methods. Norovirus infection was diagnosed by reverse-transcriptase polymerase chain reaction. Strains were genotyped by nucleic acid sequence of the most highly conserved region of the norovirus gene encoding the capsid S (shell) domain. Results. Ten of 12 patients presented with vomiting of short duration, but diarrhea was present in all. The median time from onset to norovirus diagnosis was 1 month (range, 0.25-6.0 months). Eleven patients were receiving immunosuppression when norovirus infection was diagnosed: 8 for graft-versus-host disease (GVHD) in an organ other than gut, 1 for previous gut GVHD, and 2 for presumed gut GVHD that proved to be norovirus gastroenteritis. Six patients required enteral or parenteral nutrition for severe weight loss. In 10 patients, diarrhea lasted a median of 3 months (range, 0.5-14 months) and virus was shed at a high level throughout. The remaining 2 patients died after 4 months of diarrhea (one died of unrelated complications, and the other died of malnutrition). The noroviruses found were GII (untyped), GII-3, GII-4, and GII-7 in 1, 1, 9, and 1 patients, respectively. Eleven of the 12 patients had acquired their infection in the community. Phylogenetic analysis of the GII-4 strains demonstrated that all differed. Conclusions. Noroviruses are a hitherto unsuspected cause of prolonged morbidity and mortality in adults after allogeneic HSCT. The use of reverse-transcriptase polymerase chain reaction to detect high viral load levels in feces distinguishes norovirus gastroenteritis from gut GVHD. [ABSTRACT FROM AUTHOR]

Helicobacter pullorum was first isolated from the faeces and carcasses of poultry and has been associated with human gastroenteritis. The aim of this study was to examine interstrain genetic diversity within H. pullorum. Two fingerprinting techniques were used: amplified fragment length polymorphism (AFLP) and pulsed field gel electrophoretic (PFGE) analysis. The 20 strains examined were from four countries and comprised 13 human isolates and seven poultry isolates. Their identity was confirmed by a species-specific PCR assay. The human and poultry isolates had distinct genotypes and most strains showed a high degree of genetic diversity. Genotyping also indicated a clonal origin for two strains from the same poultry flock, and established a close relatedness between three chicken carcass isolates from a processing plant. It is concluded that these two genotyping techniques will provide a useful basis for future epidemiological investigations of H. pullorum in poultry, and may provide a link with its possible causal role in human gastrointestinal infections. [ABSTRACT FROM AUTHOR]