testing and symptoms question

[tr50]

Dr, I have seen where you have stated to start testing at 4 weeks then from 6 to 8 weeks and that a negative at 6 weeks is 99% accurate, 8 weeks 100%, what is the percentage for a 4 week test? when i say test I mean antibody test (home access) notice ther are different kinds of tests. I have a 4 week negative but am conscirned did show strange symptoms within 2 to 4 weeks wich you and everyone states did not sound like hiv symptoms anyway, was relieved after 4 week test, until girlfriend ended up with 1 or 2 very small canker sores just inside bottom lip, stated they didnt hurt and were smaller than any canker sore i ever had wich always hurt, she stated she has never had one her entire life (27 yrs) shes knows nothing of my low risk exposure, and now has a stiff neck. no other symptoms.
1 what percentage of people serconvert within 4 weeks?
2 what do you make of her symptoms, my research seems to indicate its not the norm to present with just a couple symptoms like these, especially thes 2 symptoms, any input?
3 Its strange to me that one can be exposed but not infected
so in other words hiv can enter into you through sex but if there is not enough virus at the time it cant replicate? how does that all work?

[normforr]

A related discussion, Symptoms was started.

[tr50]

Thank you for the insight Dr H, the symptoms I described were my girlfriends, who I slept with unprotected after what i believed was a risky behavior, I was the one who had protected sex at massage parlor with an asian woman and there was a large amount of blood on the condom so stopped immediately, she then wiped the condom with a tissue, removed condom and then left room, returned and performed habd job on me, was worried if there were traces of blood either on her hand or on my penis after removing condom, symptoms began wich I described to you on a previous post in detail and were spread out over a two week period and you had stated my symptoms did not sound like HIV anyway, but to test to relieve my anxiety, wich I did at 4 weeks (antibody test) Home access. came back negative, was relieved until girlfriend came down with a small canker like sore in her mouth and a stiff neck all within the 2 to 4 week window. just took 61/2 week antibody test to be sure, and to relieve my renewed anxiety, if it is negative I will do no more testing and accept those results. Thanks for the detailed response on how one is infected, just out of curiosity after your explanation, I wonder If one can be exposed with a small amount of HIV but not enough to infect and still come down with symptoms because they were exposed to a virus but not a large enough amount to replicate itself. I have foud of no one becoming infected by an exposure of my nature and have been told there would have to be a very large amount of blood on the females hand to actually infect, any furthe input would be appreciated. Thanks DR

[H. Hunter Handsfield, M.D.]

There are not very precise statistics on time to positive HIV test.  But 90% probably is about right for a 4 week test.

As I have said innumerable times, symptoms NEVER reliably indicate HIV infection.  Test results ALWAYS are more valid evidence than symptoms.  And your symptoms really do not suggest HIV anyway.

The reasons HIV is not efficiently transmitted are very complex. But you are sort of on the right track about one factor:  it takes lots of virus.  Nonprofessionals tend to assume 'it only takes one virus particle'.  Not true.  All infectious diseases are transmitted with variable efficiency.  For example, to infect a human volunteer Shigella (the bacteria that causes bacterial dysentery, a bad diarrheal disease, the research volunteer needs to swallow ~50 Shigella organisms.  To get samonellosis (a common cause of food-borne infectious diarrhea) the same experient requires the volunteer to swallow 50,000 organisms--i.e., it is 1000 times less infectious than Shigella.  Heptatitis B is much more easily transmitted by blood exposure than HIV, because it takes a much lower dose of HBV for infection to 'take' than for HIV.

Bottom line:  You don't say what your exposure was.  But if it was heterosexual exposure with a partner of unknown HIV status, assume 1% chance the person was infected and 1 in 1000 chance of transmission, then even before you were tested the odds you have HIV cauclate at 0.01 x 0.001 = 0.00001, or 1 chance in 100,000.  Add a 4 week negative test which picks up 90% of infections, and your odds of actually having HIV go down to 1 in a million.  Therefore, your 90% reliable test is extremely reassuring:  do you realling think you're going to hit the 1 in a million lottery?

So if you remain nervous, have another test.  But it seems you have no worries of significance.

Good luck--  HHH, MD