Pathologist Questions Tuberculosis

How would doctors diagnose TB?

My father is 60 years old and he has been coughing persistently. Is there a possibility it could be tuberculosis? I know this is found via a blood sample, but is that definitive? Or would further diagnosis be required?

5 Answers

Screening for TB can be easily done with a PPD test, which is a skin reactivity test. A bit of TB-like material is injected under the skin. If a reaction occurs after a couple of days, the test is considered positive. Follow up of a positive test usually includes chest imaging.
Blood testing would be fairly definitive. They may try a PPD first. A more invasive test would be by lung biopsy. They could also collect sputum and test it for TB as well. Less invasive than a biopsy. Lots of options for your father.

RB Thomas, MD
That means your father has been infected by tuberculous (TB) bacteria. However, more tests are required to determine that this is a latent TB or active TB infection.
The most reliable test is the three sputum samples collection they send them to the lab and they try to grow the bacteria it takes a long time also they can put a PPD on your skin also called mantoux test
A combination of physical examination, chest X-rays, skin and laboratory testing that includes serology "Quantiferone test", sputum exam for acid fast organisms, by direct staining and culture, pathological examination of a sample obtained through a fine needle biopsy of an observed, usually lung lesion.