PEP and Seroconverion Delay?

This is posted after the case in: http://www.medhelp.org/forums/STD/messages/2646.html

This is a follow up on the above link.

Yeah I was having a similar “incidence” on 10/4/2008, where I was having a condom break accident with a confirmed positive, and I am the anal receptive. I have never had unsafe sex before. I was on extended PEP 40 hours later with 3TC, Viread and Stocrin. I tested negative 6 and half weeks after exposure. It gives me some comfort but I know it is far from being conclusive, although experts (my doctors) claimed that there is no evidence that PEP can delay antibody testing. So what had you found out at the 3 and 6 months mark, Maxxy35? And at this stage, Dr. HHH, do you have anything to add on since it has been 2 years after your last response to Maxxy35? Today is 28/5/2008. I will definitely retest on the 3 and 6 months mark. Thanks you for all of you to take notice on my question.

[ECN44120]

US testing guidelines after PEP are that the person should test up to 6 months, becouse PEP can delay seroconversion reducing the viral load at infection but not completly erasing it, and the it would take longer to have a high viral load and then longer to produce antibodies for hiv, that are the ones looked for in the tests. Thats is the logic behind the 3 and 6 months testing guideline after PEP.

Hope it Helps

[regularjoey]

Yes, PEP inhibits HIV replication and therefore can delay recognition of HIV by the immune system.  So the rule of thumb is to count the window period after the last dose of PEP.