PPD/TB (Tuberculosis) test/screening (Frankfurt)

Hello! I am an American nurse, just moved to Marburg in March. My husband is working for Siemens and I am staying home. Right before I left the USA I was exposed to a patient with Tuberculosis, or TB. Normal protocol is to receive a test for TB, or PPD (I am told this is a "prick test" in Germany) immediately and then another in 2 months time. It has now been 2 months. Normally I would have the test done at the hospital where I worked but I am not working here. I could also have it done at the health department in the US. Can anyone tell me how to go about getting one of these tests?

I have an appointment next week with a general practitioner but that seems like overkill--it is a simple test that a nurse or a medical assistant can do. I am also concerned about how much it will cost. I am covered by my husband's insurance through work but I don't know how it works here in Germany.