Stachybotrys
Stachybotrys, commonly referred to as black mold, is a type of mold that thrives on wet, cellulose-containing materials such as paper, wood, and textiles. It is known for producing various mycotoxins, including trichothecenes and hemolysin, which can pose health risks to humans and animals. This mold is slower-growing and often overshadowed by other molds in damp environments but can persist in a dormant state for years until water becomes available. Stachybotrys is frequently found in buildings affected by water damage, such as those with leaks or flooding.
Health concerns related to Stachybotrys primarily arise from its mycotoxins, which have been linked to serious health issues, including respiratory problems and neurological deficits. Cases of lung hemorrhage, particularly in infants living in water-damaged homes, have drawn significant attention to its potential hazards. To mitigate risks, it is crucial to prevent water damage and address any mold growth promptly, ideally within 24 hours. While antifungal treatments are not typically used due to Stachybotrys not causing direct human infections, maintaining a balanced diet rich in antioxidants may help mitigate the effects of exposure to its mycotoxins.
Stachybotrys
- TRANSMISSION ROUTE: Ingestion, inhalation, skin
Definition
The pathogen Stachybotrys is a mold that grows on wet cellulose-containing materials. Stachybotrys produces a number of mycotoxins, including several trichothecenes and a hemorrhagic protein called hemolysin. Memnoniella is a related fungus that has similar growth characteristics and produces similar mycotoxins.
Natural Habitat and Features
Stachybotrys is a black or gray fungus (mold) with worldwide distribution. Stachybotrys grows on wet cellulose-containing material such as hay, leaves, paper, wood, wall board, textiles, rugs, drywall, and insulating materials. Stachybotrys is a fairly slow grower and may be overrun by other molds growing on cellulose-containing substrates.
Stachybotrys requires wet conditions to grow; however, Stachybotrys spores can remain dormant under dry conditions for several years and can resume active growth and mycotoxin production when water becomes available. The Stachybotrys mycotoxins can also retain their potency over several years without active Stachybotrys growth. Stachybotrys frequently grows in buildings that have been flooded by leaking pipes or toilets, rain infiltration, or natural disasters, including hurricanes.
Stachybotrys spores are often hard to grow in culture. Some studies have reported that cellulose-based media or cornmeal media is best for cultured Stachybotrys growth.
Stachybotrys spores are not as readily spread by air as are most mold spores. Several published studies have been unable to collect any airborne Stachybotrys spores, even though the buildings in question may be contaminated with many square meters of Stachybotrys growth. Relying on airborne samples only has led many indoor air investigators to falsely conclude that Stachybotrys was not growing in the structures under investigation. Because Stachybotrys spores are not readily dispersed in the air and are hard to grow in culture, all mold sampling studies that suspect Stachybotrys growth should take surface, tape, or building material samples from the building.
Pathogenicity and Clinical Significance
Localized Stachybotrys infections have been reported. Viable Stachybotrys was isolated from the lungs of a seven-year-old boy living in a water damaged farmhouse with heavy Stachybotrys growth. The boy, who experienced severe fatigue, chronic coughing, and lung hemorrhage, completely recovered after cleanup of his mold-infested home. Unpublished observations have reported Stachybotrys growth in nasal sinuses; however, the main health concerns are connected to the mycotoxins and allergens produced by Stachybotrys.
The Stachybotrys mycotoxins were first reported as contaminants of animal feed and human food. In the 1940s, there were reports of domestic animals dying in the Soviet Union after eating Stachybotrys-infested hay. In later years, attention has been focused on humans who are exposed to high levels of Stachybotrys and its mycotoxins in indoor air and dust.
Stachybotrys produces a wide range of mycotoxins, including the trichothecenes satratoxin, roridan, and deoxynivalenol. The amounts and types of triochothecenes produced vary considerably depending on environmental conditions and the Stachybotrys strain. The trichothecene mycotoxins damage the immune and nervous systems, inhibit protein synthesis, and can cause vomiting. Animal studies have reported that exposure to small amounts of trichothecenes can damage brain cells.
Stachybotrys also produces a protein called hemolysin, which causes lung hemorrhage in nonhuman animals and may be linked to human lung hemorrhage. In the 1990s, life-threatening lung hemorrhage was reported in ten infants in Cleveland, Ohio, who lived in water-damaged homes. Airborne levels of Stachybotrys, Aspergillus, and other molds were much higher in the homes of the infants with lung hemorrhage than in the control homes.
The allergens and mycotoxins from Stachybotrys can also worsen asthma and nasal problems. Several studies have reported that heavy indoor exposure to Stachybotrys and other molds is associated with significantly poorer lung function and significant deficits in many neuropsychiatric parameters, such as reaction times, color vision, memory, concentration, grip strength, and vocabulary.
The ideal way to control Stachybotrys and its mycotoxins is to prevent exposure to the mold. The best way to control Stachybotrys growth is to prevent indoor water damage. All cases of indoor water damage, standing water, or visible mold growth should be cleaned within twenty-four hours to prevent growth of Stachybotrys and other fungi and bacteria. For large cases of water damage, one should contact a flood remediation company.
Several studies have reported that clean-up and water remediation of homes with heavy Stachybotrys growth are associated with less asthma, fatigue, and concentration and memory problems in the occupants of the contaminated home.
Drug Susceptibility
Because Stachybotrys does not appear to cause human infection, antifungal drugs are generally not used to treat persons who have been exposed to Stachybotrys. However, some studies have reported that the use of the bile-binding drug cholestryamine may be useful in speeding human excretion of trichothecene mycotoxins. Other research has suggested that eating a well-balanced diet that is high in antioxidants (vitamins A, C, and E, and l-carnitine and coenzyme Q10) can reduce the toxic effects of many mycotoxins.
Bibliography
Elidemir, Okam, et al. “Isolation of Stachybotrys from the Lung of a Child with Pulmonary Hemosiderosis.” Pediatrics 104 (1999): 964-966.
Etzel, Ruth, et al. “Acute Pulmonary Hemorrhage in Infants Associated with Exposure to Stachybotrys atra and Other Fungi.” Archives of Pediatric and Adolescent Medicine 152 (1998): 757-762.
"Facts About Stachybotrys Chartarum." Centers for Disease Prevention and Control (CDC), 29 May 2024, www.cdc.gov/mold-health/data-research/facts-stats/index.html. Accessed 4 Feb. 2025.
Kilburn, Kaye. “Neurobehavioral and Pulmonary Impairment in 105 Adults with Indoor Exposure to Molds Compared to 100 Exposed to Chemicals.” Toxicology and Industrial Health 25 (2009): 681-692.
Samson, Robert, Ellen Hoesktra, and Jens Frisvad. Introduction to Food and Airborne Fungi. 7th ed. Utrecht, the Netherlands: Central Bureau for Fungal Cultures, 2004.