Building-Associated Pulmonary Disease From Exposure toStachybotrys chartarum and Aspergillus versicolor

Abstract

The authors present an outbreak of disease associated with exposure to Stachybotrys chartarum and Aspergillus species. A courthouse and two associated office buildings had generated discomfort among employees for two years since initial occupancy. Multiple interventions had been unsuccessful An initial evaluation of 14 individuals identified three with potential asthma and three with symptoms consistent with interstitial lung disease. A clinical screening protocol to identify individuals who should be removed from work identified three likely and seven possible cases of building-related asthma. Detailed environmental and engineering assessments of the building identified major problems in mechanical system design, building construction, and operational strategies leading to excess moisture and elevated relative humidities. Moisture-damaged interior surfaces in both buildings were contaminated with S. chartarum, A. versicolor, and Penicillium species. Aspergillus species, especially A. versicolor, at concentrations of 10(1) to 10(4)/m3 dominated the indoor air under normal operating conditions. Bulk samples also revealed large quantities of Stachybotrys. A questionnaire survey of the three case and two control buildings documented between three- and 15-fold increases in symptoms. A nested case-control study suggested emphysematous-like disease in individuals meeting questionnaire definitions for cases. Replication of analysis strategies used in similar previous investigations suggested an association between worsening symptoms and decreased diffusing capacity of the lung. Performance on neuropsychological measures was similar for both cases and controls, although workers with symptoms reported increased levels of current but not past psychiatric symptomatology. Chemical analyses demonstrated the presence of satratoxins G and H. Cytotoxic laboratory analyses demonstrated the presence of agents with biological effectiveness in bulk materials. No association was seen between IgE or IgG antibodies and the presence of disease. This outbreak represents a likely human response to inhaled fungal toxins in indoor environments. Moisture indoors represents a public health issue currently inadequately addressed by building, health, or housing codes.

Idiopathic pulmonary haemosiderosis revisited

“…A series of articles linking environmental exposure to fungi (especially Stachybotrys atra) in water-damaged houses in Cleveland, OH, USA and infantile pulmonary haemosiderosis led to an extensive investigation of possible infectious or mycotoxigenic pathogenesis [46][47][48][49][50][51][52][53][54][55][56][57][58]. The postulated mechanism is that fungal toxins called trichotecens, which are potent protein synthesis inhibitors, impede the angiogenesis underneath the rapidly forming alveolar membranes, making the acinar region prone to bleeding.…”

Fungal spores: hazardous to health?

“…Severe inflammatory changes, including hemorrhage, were observed in mice receiving toxic spores of this species. Two recent studies report occupational illness associated with chronic, low-level exposure to S. chartarum in water-damaged office buildings (27,28). Dill et al (29) noted massive development of S. chartarum on decomposable flower pots made of recycled paper, which led to the development of very painful inflammed efflorescences at the fingertips followed by scaling of the skin.…”

Clinical experience and results of a Sentinel Health Investigation related to indoor fungal exposure.

“…High exposure levels of airborne pathogenic fungi in the work environment have been reported among farmers, woodworkers, and composting waste workers but may also be found among hospital and office workers or occupants of homes with significant water damage or with defective ventilation systems (4)(5)(6)(7). In recent medical/epidemiologic investigations, an association has been described between high exposure to S. chartarum and toxic inflammatory effects in infants (8)(9)(10), in office workers handling moldy paper materials and breathing fungal-contaminated air (11,12), and in courthouse workers (13). These effects are thought to be related to toxic metabolites (mycotoxins) produced by certain fungi such as those in the genera Stachybotrys, Aspergillus versicolor, Penicillium, Trichoderma, and Fusarium. S. chartarum appears clinically important because it produces biologically very potent mycotoxins such as trichothecenes (i.e., satratoxins) and spirolactons that interfere with protein synthesis on the DNA level and the cellular or humoral immune system in in vitro systems (14,15).…”