Surveillance will determine whether a new law regulating cooling towers reduces the incidence of Legionnaires’ disease.

trated on the morphologic appearance of the larger ulcerative lesions. In one study, examination of 419 lesions in an unspecified number ofcarcasses indicated no predilection for specific feather tracts; only 17 of these lesions appeared to be in wing tracts. 13 The present study was performed to characterize the location and appearance of nodular and ulcerative lesions in a large number ofcarcasses. Lesions were also examined histologically, and the histologic appearance of small nodular lesions was characterized. Through a retrospective study, the prevalence of multiple lesions at slaughter was examined in relation to individual flock production parameters and specific disease condemnations to identify associated environmental factors or diseases. Vet Pathol 30:265-270 (1993) Abstract. Multiple lesions of dermal squamous cell carcinoma are found at a low frequency (0.04%) in the carcasses of young meat-type chickens at slaughter. For this study, affected carcasses (n = 308) were removed from the processing line, and lesions were characterized by size, distribution, and morphology. Carcasses were also sexed and examined for evidence of metastasis. Nodular (n = 297) and ulcerative (n = 1,707) lesions were counted and examined. Most lesions were present in the pectoral, dorsopelvic, and femoral feather tracts. Few lesions (n = 11) were found in wing tracts. Mean diameter was 5.4 mm for ulcerative lesions and 3.1 mm for nodular lesions. Histologic sections of ulcerative (n = 579) and nodular (n = 113) lesions were examined. Small nodular lesions originated from hyperplastic feather follicle epithelium. Nodules contained keratin-filled cysts lined by squamous epithelium that were associated with isolated islands and infiltrating cords of dermal keratinocytes. Loss of surface epithelium resulted in noduloulcerative and ulcerative lesions. Invasion of underlying skeletal muscle and evidence of visceral metastasis were not present, but invasion through elastic laminae and into the subcutis was present in 20.5% (134/654) of the lesions examined. The nodular lesions in these carcasses were morphologically similar to early nodular lesions previously described in live chickens as avian keratoacanthomas. A retrospective study compared selected production parameters and disease condemnations to the prevalence of squamous cell carcinoma in 665 flocks of broiler chickens. There was a positive correlation (P < 0.000 I) with the occurrence of airsacculitis but a negative correlation with increased age and condemnations for leukosis (P < 0.000 I). Tumor frequency followed a pronounced seasonal pattern, with decreased prevalence in summer months.Key words: Avian; broilers; chickens; keratoacanthoma; skin neoplasms; squamous cell carcinoma.Neoplasms of epithelial origin are rare among avian species.t' Lesions discovered at slaughter in the skin of broiler carcasses have been described as ulcerative,2,7,8,13 noduloulcerative, and nodular.' These lesions have been histologically diagnosed as squamous cell carcinomas.2,7,13 Carca...

An outbreak of Enterobacter cloacae in the neonatal intensive care unit of a provincial hospital in Gauteng, South Africa, resulting in nine deaths was investigated. Macrorestriction analysis using pulsed-field gel electrophoresis revealed that three isolates ofE. cloacae from blood cultures of patients, six from environmental sources, and one from the hands of a staff member belonged to the same genotypic cluster.

Eight young chickens with lesions characteristic of those described as dermal squamous cell carcinoma were obtained before slaughter. Lesions were measured; representative lesions were biopsied and examined microscopically; and gross changes were monitored. Lesions appeared to originate as cystic, keratin-filled proliferations of the feather-follicle epithelium. These cysts progressed into raised, keratin-filled, and eventually ulcerated, nodules. Loss of the keratin core resulted in a shallow ulcer that became progressively flattened and regressed into a fibrous dermal scar. All lesions in the broilers regressed in 4 to 16 days (mean 14 days). Twenty roaster lesions completely regressed. For roasters, the mean time to regression was 20 days, with a range of 6 to 93 days. Although there was limited invasion of the dermis by atypical keratinocytes, the overall architecture and biological behavior were more consistent with a benign lesion.

Seven different injection sites for a Pasteurella multocida bacterin were evaluated by measuring the immune response and the local tissue reaction. Injection into the ventral surface of the tail or subcutaneously along the dorsal midline of the neck were the most suitable procedures. Ease of application was judged subjectively, and the tail site was found to be easier to inject accurately than the subcutaneous neck site. The tail injection site was found to be the best overall when immune response, tissue reaction, and ease of application were all considered.