Various members of the mold family Aspergillus are found everywhere. Many of them can cause serious diseases in humans and animals, which may be fatal if untreated. The most commonly known member of this group is Aspergillus fumigatus. Its role in causing disease is well-documented.
Spores of these molds are spread in the air. If inhaled by those with weak immune system, they can overcome the body’s defenses and start growing inside the nasal passage, sinuses and lungs. The molds may even spread to the brain and other organs through blood.
The disease caused by some Aspergillus molds is called aspergillosis. In humans, it may take the form of an allergic response, or the mold may invade and destroy the tissues of the lungs. Spores may also settle into air filled pockets inside lungs and grow into fungal balls, often seen in wild birds. In domestic cats and dogs, this mold invades the nasal cavity and sinuses, causing a condition called fungal rhinosinusitis. Often, it spreads its thread-like projections, known as hyphae, behind the eye and into the brain.
Aspergillosis can be treated with modern anti-fungals. However, the disease caused by some members of the species such as felis, lentulus and udagawae may not always be susceptible to modern drugs. This is a cause for worry for public health.