The greatest threat with the most deadly consequences comes from inhaled anthrax. One report suggested that black flies may have transmitted anthrax from animals to humans, where there was a large outbreak in the animal population. Insects are not a major factor in the spread of anthrax. Anthrax is diagnosed by isolating the bacteria, Bacillus anthracis , from the blood, skin, or cerebral spinal fluid, or by measuring specific antibodies in the blood of suspected cases. Generally, diagnosis by antibodies is done weeks or months after the infection occurs, too late to aid in treatment.
Immunization is the safest, most effective way to provide protection against anthrax.
The incubation period for inhalation anthrax is 1 to 6 days. The initial symptoms of inhalation anthrax are so nonspecific that diagnosis is very difficult. Therefore, antibiotic treatment must be started at the earliest sign of disease. Antibiotics may protect people without symptoms after a known exposure to aerosolized anthrax spores, but may be ineffective following a large dose, unrecognized exposures, or exposures recognized only after symptoms appear. Anthrax spores are odorless, colorless, and tasteless.