sorry i meant if at 12 weeks it is still NEGATIVE, he didnt catch it.
i guess the 1 in 2000 comes from the ratio of the number of people who are infected and the number of people who are at. How else would they come up with that figure? But thats wrong what he said, if it is negative at 4 weeks, it still means it is 95% accurate and he has a 5% chance left that he actually caught it off the definitely hiv positive person. Coz, if at 12 weeks it is still positive, he didnt catch it.
You should refrain from answering questions on this forum if you don't know what the window period is.
which window period is that?
That's not true either. Four weeks is not even out of the window period.
No doubt. But if you've had a single low-risk exposure and have a negative test at 4 weeks, and the person was HIV positive, the chances of that being true would be 1 in 20,000