Human infection caused by Salmonellae of subspecies II to VI in Germany, 1977-1992

Abstract

Human infections by Salmonella (S.) are usually caused by S. enterica strains belonging to the subspecies I (subsp.). Strains of subsp. II-VI and S. bongori are mostly isolated from animals or environmental specimens, and they are therefore considered as less pathogenic for humans. Out of 90,201 S. isolates examined at the German National Reference Centre for Enteric Pathogens between 1977 to 1992, 89,798 (99.55%) belonged to S. subsp. I, while 403 (0.45%) of strains belonged to S. subsp. II-VI and S. bongori (formerly called subsp. V). 108 strains belonged to subsp. II, 241 isolates to subsp. IIIa and IIIb (formerly called Arizona), 49 to subsp. IV, 4 to S. bongori and one isolate to subsp. VI. 215 of the 403 isolates (53.4%) were from humans, 101 (25.1%) from reptiles, 52 (12.9%) from various warm-blooded animals, 11 (2.7%) from foodstuffs and 12 (3.0%) from environmental specimens. The origin of 12 (3.0%) strains was unknown. According to the clinical diagnosis reported by the laboratories, intestinal disease was associated with 176 (81.9%) out of 215 strains of human origin. 11 (5.1%) strains had been isolated from extraintestinal infections (sepsis, atypical pneumonia, urinary tract and wound infections), and 28 (13.0%) strains from stool specimens of healthy persons. A slightly higher incidence was observed in children of 0-5 years of age (49 cases; 22.8%). Male persons were twice as often affected than females. The seasonal incidence of infections was highest in October and in February. In 53 cases (24.6%), travel to a foreign country was reported.