Evaluation of Stachybotrys chartarum in the house of an infant with pulmonary hemorrhage: Quantitative assessment before, during, and after remediation

Stachybotrys chartarum is an indoor mold that has been associated with pulm onary hemorrhage cases in the Cleveland, Ohio, area. This study applied two new quantitative measurements to air samples from a home in which an infan t developed PH. Quantitative polymerase chain reaction and a protein synthe sis inhibition assay were used to determine the level of S. chartarum spore s and their toxicity in air samples taken before, during, and after a remed iation program was implemented to remove the fungus. Initial spore concentr ations were between 0.1 and 9.3 spores/m(3) of air, and the toxicity of air particulates was correspondingly low. However, the dust in the house conta ined between 0.4 and 2.1 x 10(3) spores/mg (as determined by hemocytometer counts). The remediation program removed all contaminated wallboard, paneli ng, and carpeting in the water-damaged areas of the home, In addition, a so dium hypochlorite solution was used to spray all surfaces during remediatio n. Although spore counts and toxicity were high during remediation, air sam ples taken postremediation showed no detectable levels of S. chartarum or r elated toxicity. Nine isolates of S. chartarum obtained from the home were analyzed for spore toxicity, hemolytic activity, and random amplified polym orphic DNA banding patterns. None of the isolates produced highly toxic spo res (>90 mu g T2 toxin equivalents per gram wet weight spores) after growth for 10 and 30 days on wet wallboard, but three isolates were hemolytic con sistently. DNA banding patterns suggested that at least one of these isolat es was related to isolates from homes of infants with previously investigat ed cases.