"Stachybotrys is the fungus that I often say must have a good press agent," says Linda Stetzenbach, director of the microbiology division at the Harry Reid Center for Environmental Studies at the University of Nevada, Las Vegas. "Anybody who writes an article [on fungus] focuses on Stachybotrys because it can be a very potent mycotoxin producer. Chaetomium, however, can produce many toxins with a similar potency, yet Stachybotrys gets all the publicity."
"I guess I inadvertently started the whole thing," says Bruce Jarvis, professor of chemistry at the University of Maryland. Jarvis first published work on Stachybotrys chartarum when he studied samples gathered in Eastern Europe in the 1980s. He and his coworkers knew that Stachybotrys produced many compounds, but what they could most easily detect was a group of compounds called trichothecenes.
Then, Jarvis continues, "in 1985 or so, I was contacted by a fellow in Chicago who had been called in to investigate a home where people had been having medical problems. He found that they had a very heavy contamination of Stachybotrys. ... I told him that Stachybotrys tended to produce relatively small amounts of trichothecenes, and it produced lots of other things besides. But I told him I would be happy to do an analysis. So he sent me contaminated building materials, and I was somewhat taken aback. The materials had quite a bit of the macrocyclic trichothecenes. The people's symptoms were entirely consistent with exposure to these toxins," Jarvis says, "and we published a paper describing this case."
In 1994, in Cleveland, an outbreak of pulmonary bleeding in infants occurred. The Centers for Disease Control & Prevention investigated, and, according to CDC's Stephen Redd, "an association was identified between increasing concentrations of spores of [S. chartarum] in case households compared to control households. That was the initial finding."
CDC and an outside panel of experts later reviewed the initial findings and stated in a report published in March 2000 that the study had a number of flaws so that the originally reported association shouldn't be considered proven. "It was sort of like we were back where we started before that investigation was done," Redd says.
Jarvis' purported troublemakers--macrocyclic trichothecenes--are highly cytotoxic. The terpenoid compounds are potent inhibitors of protein synthesis, and they work by binding to the eukaryotic ribosome to shut down protein translation.