Siam0703/SQuAD-EN-Passage-to-Question huggingface dataset:
Thus, the technological ability to detect any infectious agent rapidly and specifically are currently available. The only remaining blockades to the use of PCR as a standard tool of diagnosis are in its cost and application, neither of which is insurmountable. The diagnosis of a few diseases will not benefit from the development of PCR methods, such as some of the clostridial diseases (tetanus and botulism). These diseases are fundamentally biological poisonings by relatively small numbers of infectious bacteria that produce extremely potent neurotoxins. A significant proliferation of the infectious agent does not occur, this limits the ability of PCR to detect the presence of any bacteria.

Questions:
What technological ability with regards to detection is currently available?
What are the remaining blockades to the use or PCR as a standard tool of diagnosis?
What are some diseases which won't benefit from PCR methods?
PCR can't detect the presence of any bacteria when what doesn't occur?