Natural Occurrence of Leptospira icterohaemorrhagiaein an Opossum

Serological and cultural studies for leptospirosis were conducted on 37 opossums trapped at a military reservation at Aberdeen, Md. Five of the 37 animals were serologically positive. Questionable reactions were seen in serums from 9 other animals. Two isolates were obtained and identified as Leptospira ballumand L. icterohaemorrhagiae, respectively. L. icterohaemorrhagiaein an opossum had not heretofore been reported. The antigenic interrelationships among the “complete” and “incomplete” bio-types of L. icterohaemorrhagiaeand L. mankarso, disclosed in the serologic studies, differed from previously reported findings.