Re: Question about West Nile Virus...
I think that the highest viremia in humans occurs a week to few weeks after infection. Also, the diagnosis of WNV is made by examining serum for antibodies, but there is some problem of selectivity if someone contracted a related disease (e.g. Japanese encephalitis, or other encephalitides). Also, I can't remember the length of time that antibodies can be detected post-infection, but I recall from one of the CDC WNV meeting talks that there was an issue with detecting antibodies from a previous year in hosts; I just can't remember if this was human hosts, or avians.
Anyway, the CDC website should have most of the answers to the questions you seek because the talks from the annual meetings are always incorporated into their site.