AN OUTBREAK OF NONTOXIGENIC CORYNEBACTERIUM-DIPHTHERIAE INFECTION - SINGLE BACTERIAL CLONE CAUSING INVASIVE INFECTION AMONG SWISS DRUG-USERS

From 1990 to 1996, a total of 65 patients from whom Corynebacterium di phtheriae had been isolated were reported to the Swiss Federal Office of Public Health. A retrospective review of medical and microbiologica l records as well as results of ribotyping of available isolates was p erformed. Twenty-seven patients had acquired their infection without e vidence of use of illicit drugs, mostly as a skin infection imported f rom subtropical areas (20 patients:); 38 isolations were associated wi th intravenous drug use (IVDU) (skin, 15; respiratory tract, 10; blood , 13). Endocarditis was documented in nine patients with bloodstream i nfection, four of whom died. There were two additional deaths due to o verwhelming sepsis. The same ribotype of nontoxigenic C. diphtheriae w as found in 31 of the 32 examined isolates associated with IVDU. All n on-IVDU isolates had different ribotypes. Among Swiss drug users, a si ngle clone of nontoxigenic C. diphtheriae was found over a period of s everal years with a high potential to cause severe invasive infection.