What does the term PCR means? Why this noninvasive test is not popular in the diagnosis of TB ?

Environmental mycobacteria & What is Non pathogenic Ubiquitous Mycobacteria - NUM!??

 Why PCR (Polymerase Chain Reaction from peripheral blood-A noninvasive method to diagnose many a diseases of human body) is not reliable? Such environmental Bact have always been around, so why wasn't this a problem in the past? This is because modern PCR is so sensitive! In the past, it was not easy to grow mycobacteria, which meant that even if a few contaminants were present in the specimen, these would fail to grow. However, PCR is super-sensitive, and will pick up the presence of even a few molecules of mycobacterial DNA.

With a positive TB PCR, the odds are that a positive result (in an asymptomatic patient) means that there is something wrong with the test, not with the patient. In fact, I think we should coin a new term for these mycobacteria which have created so much iatrogenic harm - Non pathogenic Ubiquitous Mycobacteria - NUM!

TB PCR positive:-What to do?This is why they are ubiquitous inhabitants of the hospital environment ; and frequent contaminants in hospital settings, where they are often found in the water supply and even in the solutions in which the endometrial biopsy is sent to the lab for PCR testing