Fusariosis Associated with PathogenicFusariumSpecies Colonization of a Hospital Water System: A New Paradigm for the Epidemiology of Opportunistic Mold Infections

Abstract

We sought the reservoir of Fusarium species in a hospital with cases of known fusarial infections. Cultures of samples from patients and the environment 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 71 sink faucet aerators and 2 (8%) of 26 shower heads yielded Fusarium oxysporum. Fusarium solani was isolated from the hospital water tank. Aerosolization of Fusarium species was documented after running the showers. Molecular biotyping revealed multiple distinct genotypes among the isolates from the 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 matched 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 system of a hospital was identified as a reservoir of Fusarium species.

Widespread Occurrence of Diverse Human Pathogenic Types of the Fungus Fusarium Detected in Plumbing Drains

“…Because our swabbing method was far from exhaustive, these frequencies should be considered a minimum estimate. The fact that the six most common STs found in drains, representing 70% of the fusaria recovered, are the same six most common STs responsible for human infections strongly supports the hypothesis that plumbing surface biofilms serve as reservoirs for human pathogenic fusaria (2,3,8,32). However, while we hypothesize that STs of opportunistic fusaria are very common in our indoor environment, we are quick to point out that Fusarium infections are relatively rare, even among the severely immunocompromised and immunosuppressed (31,35,48 (13,15,41).…”

“…Collectively, these results suggest that patients inadvertently inoculated their cornea with contaminated lenses (8). This hypothesis is further supported by the fact that Fusarium has been recovered in many surveys of water systems, including surveys of municipal water system pipe sections (11) and from a hospital survey sampling plumbing fixtures (2). It has also been demonstrated experimentally that fusaria, particularly members of the FSSC and FOSC, can attach to and form biofilms on contact lenses and polyvinyl chloride pipe (14,25,32,51).…”

“…All six STs have been recovered from hospital environments, including plumbing systems (2,8,38,41,43,49,58). This connection has led to the hypothesis that indoor plumbing-associated biofilms may act as hidden source of infection in hospitals and the community.…”

Effects of Gas Flaring on the Physicochemical and Microbiological Quality of Water Sources in Egbema, Imo State, Nigeria

“…Fungi can survive and persist after treatment, or enter during installation, repairs, replacement of pipes and during depressurization events, hence contaminating the water that reaches consumers [18,19]. The inhalation of spores after aerosolisation of water may occur, when water passes through taps and showers, which is a concern for health care institutions such as hospitals [17,18,20]. Therefore, the presence of fungi in water should be considered as a primary threat as some of them are considered to produce mycotoxins and/or are opportunistic human pathogens.…”

Mucormycosis, Pseudallescheriasis, and Other Uncommon Mold Infections

“…The rise in fusariosis incidence may also be partially attributable to the routine use of fluconazole prophylaxis after transplant (5). Colonized water systems in the hospital environment have been identified as reservoirs of Fusarium, and aerosolization and patient-to-patient spread subsequently may lead to infections (69).…”