I know that Cl tetani is not invasive and strictly localised. I think toxemia means spread in the blood. I am thinking this sentence
The volume of infected tissue is small, and the disease is almost entirely a toxemia.
Cl tetani has spores. This suggests me that these spores spread through blood. They then open and become pathogenic in some tissues where they remain strictly locally (so small area/volume of infected tissue; I think area is better word, since the disease is not invasive) and pathogenic.
How do you understand the quoted sentence about pathogenesis of Cl tetani?