The other day I read that standard HIV tests have window periods that go from 4 weeks to much longer since they check for the antibodies which sometimes take a little bit longer to show up in the blood but a RNA test (which doesn’t look for the antibodies for HIV but for the genetic material of HIV itself and it’s also said that it can find out if someone is HIV positive even if their viral load is only 2 copies/ml) has a window period of only 9-14 days but if a RNA test looks for genetic material of the virus, then why does it require to be taken after 9-14 days of exposure? Is it because the virus takes 9-14 days to actually start multiplying in the blood?

4 hours ago, Ronaldo7 said:

The other day I read that standard HIV tests have window periods that go from 4 weeks to much longer since they check for the antibodies which sometimes take a little bit longer to show up in the blood but a RNA test (which doesn’t look for the antibodies for HIV but for the genetic material of HIV itself and it’s also said that it can find out if someone is HIV positive even if their viral load is only 2 copies/ml) has a window period of only 9-14 days but if a RNA test looks for genetic material of the virus, then why does it require to be taken after 9-14 days of exposure? Is it because the virus takes 9-14 days to actually start multiplying in the blood?

Yes, it's got to replicate up to the sensitivity of the pcr test.

18 hours ago, StringJunky said:

Yes, it's got to replicate up to the sensitivity of the pcr test.

Thanks for the reply. Some sources stated that a RNA test can tell if a person is positive even if their viral load is only 2 copies/ml so does this mean that HIV takes 9 to 14 days after exposure to reach 2 copies/ml?

7 hours ago, Ronaldo7 said:

Thanks for the reply. Some sources stated that a RNA test can tell if a person is positive even if their viral load is only 2 copies/ml so does this mean that HIV takes 9 to 14 days after exposure to reach 2 copies/ml?

That's what I meant. 

13 hours ago, StringJunky said:

That's what I meant. 

Thanks for the input.