Dear Dr. Daar,

I was exposed to HIV earlier this year (Jan.) and found out about 2 months afterward. I started taking sustiva/truvada in May. Before medication, vl was >100,000 and CD4 was 266. Tests showed no resistance. Second test, 7 weeks after start of meds, showed vl <400 (which was reported as undetectable) and CD4 539 and third test showed vl 102 and CD4 433, 31%. FYI, the 2nd and 3rd tests were analyzed by different labs. My question is does the fact that after 20-21 weeks of treatment that there was still a vl above 50 indicate some previously undetected resistance? The doctor thinks things are going well and said to "stay the course," but I'm not sure, especially considering the dive in CD4 levels b/t the 2nd and 3rd tests. How long should it take to acheive undetectable vl and a high CD4? In my case, it seems to be taking a long time.

Thank you for your post.

It is difficult to say what is going on based upon the information provided. It seems unlikely that you had acquired a drug resistant virus based upon your negative pre-treatment test and initial response. It is important to note that the absence of resistance detected prior to therapy using standard methods is not perfect and can miss some levels of resistance. However, these results along with the initial response you describe would appear promising that you did not start with a resistant virus. That said, at this time the most important thing is what happens with your follow-up viral load tests. If they return to undetectable levels you are golden, if not you will need to make a change, optimally after resistance testing is performed. With regards to your CD4 counts, I would not assume that a single drop from 539 to 433 is an important change. Again, follow-up measurements will ultimately answer the question.

Of course, all of my comments above assume that you are taking your medications consistently. Needless to say, one of the most common reasons for people experiencing viral load rebound is poor adherence and development of resistance.

Best, Eric