In eastern Europe, in the 1930s, outbreaks of a disease of horses and other animals that was characterized by symptoms such as irritation of the mouth, throat, and nose; shock; dermal necrosis; a decrease in leukocytes; hemorrhage; nervous disorder; and death were associated with Stachybotrys chartarum (then known as S. alternans) present in straw and grain fed to the horses.

Currently, health effects in humans attributed to Stachybotrys chartarum, are controversial. However, it is generally agreed that Stachybotrys chartarum can potentially cause allergic reactions from inhaled spores and also poses the threat of mycotoxin poisoning.

One of the disputed claims is the association of Stachybotrys with the idiopathic pulmonary hemorrhage that resulted in deaths of infants in Cleveland, Ohio, USA, in 1993-1994. After a review of the reports, the US Centers for Disease Control and Prevention (CDC) concluded that a possible association between pulmonary hemorrhage in infants and exposure to molds, specifically Stachybotrys chartarum, was not proven.

Spores of Stachybotrys are believed to contain high concentrations of mycotoxins. Therefore, inhaling large numbers of these spores potentially can cause mycotoxin poisoning. Luckily, spores of Stachybotrys are not readily disseminated in the air, primarily because they usually occur in a cluster covered with wet slime. Therefore, exposure to huge amounts of airborne Stachybotrys spores would only occur when the spores dry out and are disturbed, for example, during renovations.

Black Mold (Stachybotrys) as a New Emerging Opportunistic Human Fungal Pathogen

Recently, Stachybotrys chlorohalonata, was isolated from the sinuses of a patient. This is the first reported case of invasive Stachybotrys chlorohalonata sinusitis. The patient was cured from this infection after sinus surgery and antifungal treatment.

S. chlorohalonata is very closely related to S. chartarum. It differs morphologically from S. chartarum by having smooth spores, and having more restricted growth on lab media.