Aus govt requests Chest X-ray numero dos

So for my second visa, I am required to give a second costly chest x-ray! When I questioned my case officer, she confirmed that since I spent more than 6 months in China, I will again have to confirm my tuberculosis-freeity via xray again:

Me: Hey so I had an x-ray last year when I applied for my current visa. I spent a lot on it, are you sure I have to get it again?

Zoe, my case officer: Hmm, is that so? Let me look it up.

2 minutes on the phone pass

Zoe: Yes I see here you got the x-ray

Me: And I am tuberculosis free!

Zoe: Yes you are. But they are only good for one year and your x-ray expires... today.

Me: Doh!

Does tuberculosis linger and then jolt you like a dodgy appliance, waiting to strike? My lungs are probably decrepit from the pollution from my stay in China, but I hopefully did not contract this ------->

However after further research, I found that one in three people in the world are thought to have TB! In 2007 there were an estimated 13.7 million chronic active cases, 9.3 million new cases, and 1.8 million deaths, mostly in developing countries. The distribution of tuberculosis is not uniform across the globe; about 80% of the population in many Asian and African countries test positive in tuberculin tests, while only 5–10% of the US population test positive.