A Penn State study found the fungus Fusarium in bathroom sink drains, suggesting that plumbing systems may be a common source of human infections.

Researchers at the school’s College of Agricultural Sciences sampled nearly 500 sink drains from 131 buildings — businesses, homes, university dormitories and public facilities — in Pennsylvania, Maryland, Virginia, North Carolina, South Carolina, Georgia, Florida and California.
They analyzed fungal DNA to compare the spectrum of Fusarium species and sequence types found in drains with those recovered from human infections.

“With about two-thirds of sinks found to harbor Fusarium, it’s clear that those buildings’ inhabitants are exposed to these fungi on a regular basis,” said lead investigator Dylan Short, who recently completed his doctorate in plant pathology. “This strongly supports the hypothesis that plumbing-surface biofilms serve as reservoirs for human pathogenic fusaria.”

In one high-profile case, Fusarium was found to have caused a widely publicized 2005-06 outbreak of fungal keratitis — infection of the cornea — among contact-lens wearers.