Fusariosis associated with pathogenic Fusarium species colonization of a hospital water system: A new paradigm for the epidemiology of opportunistic mold infections

We sought the reservoir of Fusarium species in a hospital with cases of kno wn fusarial infections. Cultures of samples from patients and the environme nt were performed and evaluated for relatedness by use of molecular methods . Fusarium species was recovered from 162 (57%) of 283 water system samples . Of 92 sink drains tested, 72 (88%) yielded Fusarium solani; 12 (16%) of 7 1 sink faucet aerators and 2 (8%) of 26 shower heads yielded Fusarium oxysp orum. Fusarium solani was isolated from the hospital water tank. Aerosoliza tion of Fusarium species was documented after running the showers. Molecula r biotyping revealed multiple distinct genotypes among the isolates from th e environment and patients. Eight of 20 patients with F. solani infections had isolates with a molecular match with either an environmental isolate (n =2) or another patient isolate (n=6). The time interval between the 2 match ed patient-environment isolates pairs was 5 and 11 months, and 2, 4, and 5. 5 years for the 3 patient-patient isolate pairs. The water distribution sys tem of a hospital was identified as a reservoir of Fusarium species.