The anthrax infection in the case of humans can proceed without any visible symptoms. With the help of the precipitation reaction the anthrax antigen can be detected in the blood of an animal. It is assumed that the distinct clinical form of anthrax infection occurs very seldom in symptomless form.
Trans. of Zeitschrift fuer Immunitaetsforschung, Allergie und Klinische Immunologie (Germany) v79 p199-205 1933.