Background: yersiniosis is a reportable disease in rptr's state. From 1997 to 2001, 48-69 cases were reported annually (medial of 53 cases per year). Most of these cases are due to infection with yersinia enterocolitica, but occasionally other species are reported. Source of the isolate is not always reported. Most isolates come from stool (14-26 per year), with a few from urine (1-4 per year) or blood (1-5 per year). During the years 1997 to 2001, only one isolate from a wound was reported (2001). In addition to cases being reported through the usual disease reporting channels, isolates are sometimes received at dept of health lab for identification. These reports would also be included in the disease statistics. This is the context in which the current reports occurred. Summary: eight isolates of yersinia spp from sources other than stool or urine were reported to the dept of health in april and may, 2002; an add'l one is pending. They were all obtained post-surgery. Initially, the lab for facilities a and b (actually located at facility a) reported 5 isolations from post-surgical specimens. Lab verified the identification of these isolates as yersinia enterocolitica. By pulsed-field gel electrophoresis (pfge) 4 were identical; referred to by lab as pattern 1. Pfge on the fifth isolate is underway. The lab for facilities a and b recovered the yersinia enterocolitica on "cdc blood agar oxyplate" mfg by oxyrase (see www. Oxyrase. Com. Oxyrase, inc; p. O. Box 1345, mansfield, oh 44901; tel 419/589-8800). This is an anaerobic blood agar plate. Facility a determined that the oxyplate was the source of the yersinia, and contacted the co to report their findings that the plates were contaminated. Facility c reported a post-surgery finding of yersinia enterocolitica. Lab verified the identification and pfge analysis identified it as distinct from pattern 1; it is called pattern 2. This lab was using plates from becton dickinson (initially they reported using plates from bbl). Facility d grew yersinia spp from a post-surgical swab received from a dr's office. They forwarded the isolate to health dept lab for further identification, where it was identified as yersinia kristensenii. This lab was using plates from bbl. Facility e grew yersinia from a post-surgical swab from a dr's office. They forwarded it to facility d, who sent it on to lab without doing anything to it. Lab identified it as yersinia enterocolitica, pfge pattern 3, distinct from patterns 1 and 2. Facility e lab was using plates from becton dickinson. Lastly, there is an isolate pending from facility f, which reported finding yersinia enterocolitica in a gallbladder. This isolate was submitted to lab in response to a memo sent to all microbiology labs in state by health dept on 5/2002, soliciting all non-stool isolates of y. Enterocolitica. Facility f lab was using media from bbl. Lab is in the process of identifying this isolate (6/2002). (note: it appears that becton dickinson sells bbl media). In summary, this cluster of post-surgical specimens yielding yersinia spp is very unusual in the state, where most yersiniosis is reported from stool cultures, from pts having diarrhea. The presence of two species of yersinia, and 3 strains of y. Enterocolitica suggests a mixed yersinia flora is involved. Detailed case reports: cases 1,2,3,4 and 10 are associated with facilities a and b. These are two separate hosps that are affiliated. They share one lab (located at facility a). They order supplies together. They are not affiliated with any other facility. The initial report came from a county health dept that facilities a and b were reporting two positive yersinia cultures occurring within 2 days from post-surgical pts. This case was reported to state disease reporting system, a web-based disease reporting system developed by the dept of health. It was first entered in this system by the local health dept. On reviewing system for add'l yersinia cases, rptr found this report. This pt is from a different county than cases 1-4. Pt works in a paper mill and injured hand at work on a wire. At first it was minor pinpoint wound from a paper bale. The next day it became red and swollen. Pt had fever to 102 degrees, continued pain, draining, swollen lymph glands and lymphangitis in arm. Pt had fever to 102 degrees, continued pain, draining, swollen lymph glands and lymphangitis in arm. This pt was admitted four days later for two days due to cellulitis and for an incision and drain procedure on the abscess. While in the hosp pt had a low grade fever and some diarrhea. The physician attributed the diarrhea to antibiotics. The lab at facility c reports: there were two positive cultures: one taken at 10am in the er and one taken at 3 pm from surgery. Both were positive for yersinia enterocolitica. One of these isolates was sent to health dept lab which verified this was y. Enterocolitica, and pfge pattern was pattern 2. Facility c reports they have had no other non-stool yersinia positives lately. No new reagent or product was in use in the lab. They reported that they used blood agar, chocolate agar and macconkey agar to culture these specimens; they were unable to tell exactly which agar it grew on. Initially they reported their blood agar comes from bbl. Later the supv reported their agar comes from becton dickinson. (since becton dickinson sells bbl media, this may account for the discrepancy).