Between mid-1970 and April 1, 1971, Enterobacter cloacae or E. agglomerans septicemia developed in 378 patients in 25 American hospitals while they were receiving intravenous products manufactured by one company. Each of the hospitals noted a marked increase in the incidence of such septicemia during this period. Enterobacter agglomerans (formerly designated Erwinia, herbicola-lathyri group) was better known as a plant pathogen and had been a human blood pathogen only rarely in the past. Septicemia caused by E. cloacae had also been uncommon.