The technology still has some bugs to work out [no pun intended] but PCR is a very good diagnostic tool. Immuno blots are developing along nicely as well. parasite identification is not the best understood practice in the average clinical laboratory.
If you could see the amount of specimens going through a lab and the amount of time it REALLY takes to do a good job, you will see why there is a problem.
I think the more demand for these types of tests, the better the diagnostic accuracy will become. Shroom