I guess I should say that everyone takes the test. I'm not a statistician, I'm a mathematician. The way I understand the phrase, "the test is 99% accurate" is

I guess I should say that everyone takes the test. I'm not a statistician, I'm a mathematician. The way I understand the phrase, "the test is 99% accurate" is that this means: assuming everyone were to be tested then 99% of the time you get an accurate result. Thus .99(1%) = 0.99% of the people will correctly test positive and 0.01(99%) = 0.99% of the population will incorrectly test positive.