Pulmonary

Respiratory infection in humans is relatively rare and initially presents with cold or flu-like symptoms for several days, followed by pneumonia and severe (and often fatal) respiratory collapse. Historical mortality rates were over 85%,^[12] but, when treated early (seen in the 2001 anthrax attacks), observed case fatality rate dropped to 45%.^[12][13]Distinguishing pulmonary anthrax from more common causes of respiratory illness is essential to avoiding delays in diagnosis and thereby improving outcomes. An algorithm for this purpose has been developed.^[14]

A lethal infection is reported to result from inhalation of about 10,000–20,000 spores, though this dose varies among host species.^[15] As with all diseases, a wide variation in susceptibility is presumed, with evidence indicating some people may die from much lower exposures; little documented evidence is available to verify the exact or average number of spores needed for infection. Inhalational anthrax is also known as woolsorters' or ragpickers' disease. These professions were more susceptible to the disease due to their exposure to infected animal products. Other practices associated with exposure include the slicing up of animal horns for the manufacture of buttons, the handling of hair bristles used for the manufacturing of brushes, and the handling of animal skins. Whether these animal skins came from animals that died of the disease or from animals that had simply lain on ground with spores on it is unknown.