History Of Anthrax

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ated upwind from where the cases occurred. Cases were also reported in animals located within 50km from the site (Abramova ,Grinberg, Yampolskaya, Walker)
THE ORGANISM

Figure 1. Robert Koch's original photomicrographs of Bacillus anthracis, the agent of anthrax.


Bacillus anthracis is a large, Gram-positive, spore forming, nonmotile bacillus. The organism grows readily on sheepblood agar aerobically and is nonhemolytic under these conditions. The colonies are large, rough, and grayish white, with irregular, curving outgrowths from the margin. Both in vitro in the presence of bicarbonate and carbon dioxide, and in tissue in vivo, the organism forms a prominent capsule. In tissue, the encapsulated bacteria occur singly or in chains of two or three bacilli. The organism does not form spores in living tissue: sporulation occurs only after the infected body has been opened and exposed to oxygen. The spores, which cause no swelling of the bacilli, are oval and occur centrally or paracentrally. They are very resistant and may survive in the environment for decades in certain soil conditions. Bacterial identification is confirmed by demonstration of the protective antigen toxin component, lysis by a specific bacteriophage, detection of capsule by fluorescent antibody ,and virulence for mice and guinea pigs. Additional confirmatory tests to identify toxin and capsule genes by the polymerase chain reaction have also been developed as research tools. (Keppie, Harris-Smith, Smith)
EPIDEMIOLOGY
Anthrax occurs worldwide. The organism exists in the soil as a spore. The form of the organis in infected amials is the bacillus. Only when the organism in the carcass is exposed to air does sporulation occur. ( Kaufmann)
Anthrax in humans is associated with agricultural, horticultural, or...