An outbreak of diarrheal disease due to Yersinia enterocolitica serotype 0:5 , biotype 1, involved nine hospitalized patients. The possible source of this infection was two patients who were both hospitalized with a history of several weeks of intermittent diarrhea. Person-to-person contact was the probable mode of transmission of the disease. The present report describes the second known nosocomial outbreak of infection due to Y. enterocolitica, Serotype 0:5 of Y. enterocolitica is not commonly encountered, and its involvement in an outbreak of gastroenteritis has not been previously reported. The importance of the enrichment technique in the isolation of Y. enterocolitica is demonstrated.

Two enteric pathogens, Campylobacter jejuni and Yersinia enterocolitica serogroup O:3, together with Escherichia coli, were investigated for susceptibility to UV radiation at 254 nm. The UV dose required for a 3-log reduction (99.9% inactivation) of C. jejuni, Y. enterocolitica, and E. coli was 1.8, 2.7, and 5.0 mWs/cm2, respectively. Using E. coli as the basis for comparison, it appears that C. jejuni and Y. enterocolitica serogroup O:3 are more sensitive to UV than many of the pathogens associated with waterborne disease outbreaks and can be easily inactivated in most commercially available UV reactors. No association was found between the sensitivity of Y. enterocolitica to UV and the presence of a 40- to 50-megadalton virulence plasmid.

The Vidas Chlamydia test (CHL) is an automated enzyme-linked immunofluorescence assay for the detection of Chlamydia trachomatis. Positive and equivocal results are confirmed with a blocking assay. A mouse monoclonal antibody directed against the chlamydial lipopolysaccharides was used for the test. The CHL assay is widely used in Europe, but U.S. experience with it is limited. Three clinical test sites (