Hi, Welcome to healthcaremagic. Thank you for posting your query here, I have gone through your question and I will try my best to give you some useful information. First of all, if the biopsy shows that you have TB, you can be 100% sure that the diagnosis is correct. I would even say that your doctor did the right thing by asking you to undergo biopsy, most other test in TB can be negative. And starting on anti TB medicines is the right step and I would concur with your doctor about the same. Now coming to your question of how you got TB. Any healthcare provider is at a high risk for contracting Tuberculosis because we are exposed to all sorts of bacteria and viruses and TB spreads mainly by droplet infection (Coughing, sneezing etc,.), TB bacteria almost always will be present in most of the populations, for example in India, it is estimated that at least 99% of the population would have contracted this bacteria, but only a few develop the disease owing to our innate immunity. So, the question is not about how you got the bacteria since it is very easy to get this bacteria (Particularly because you are a healthcare professional), the question is how virulent is this bacteria and how strong is your immune system. At times, even if you have a strong immune system the disease can manifest if the bacteria are very strong (highly virulent), otherwise your immunity should be a little weak for the bacteria to start multiplying in sufficient numbers to cause the disease. My suggestion to you right now is, don t freak out, it is alright, it is a simple infection like any other and it can be cured if you take the medicines regularly. Please do follow the advise of your doctor and complete the full course of your Anti-TB medicines. Hope this answers all your concerns, Please feel free to utilize our paid section if you have further concerns or questions. Wishing you speedy recovery. Warm regards, Dr. Yogesh.D