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?


Question: I want to travel to the USA while working remotely for my non-US employer
Answer: Since so many people liked the comment I thought I'd turn it into an answer.

What you are describing is done all the time by the US and non-US employees on their vacations/holidays. Technically while you are doing work in while being on US soil you are not working in the US since you're not being employed by a US employer and your travel to the US is not employment related, so apply for a tourist visa and you should be fine.

To be more specific I found several sites explaining the differences between B1/B2 and H visas in more laymen's terms, so you can try to read up on that to make your determination:


Workpermit
Wikipedia


And last but not least


State Department