Aspergillosis. Specimen of human liver infected with the fungus Aspergillus, causing the condition of aspergillosis. Nodules of the fungus (white) are seen in this sliced section of liver. The scale reference is in centimetres. The fungus Aspergillus is harmless to healthy people; spores are usually present in the air all year round. Patients with a reduced resistance, however, may become infected, sometimes with fatal results. In this instance the patient was on immunosuppressant drugs following a heart transplant. Usually the breathed in spores infect the lungs where a fungus ball may develop; here the fungus entered the bloodstream to infect the liver.