Ive been on Atripla for about 4-5 months now, in August i was undetecable and my CD4 was 719 with a CD4% of 26, i just had my blood drawn again and my VL has gone back up to 142 and my CD4 down to 592 but my CD4% went up to 29. I havent missed any of my doses at all, and im also on Valtrex and Remron. I was wanting to know, what could cause my VL to go back up like that?

Many things can cause a transient, insignificant increase in the viral load, which we call a 'blip'. It happens to 40% of people living with HIV on treatment. A recent viral infection and a recent vaccination have both been shown to lead to temporary increases in viral load. A minor lapse in medication adherence may cause an increase in viral load, so I would certainly urge you to ensure that you are doing everything within your power to take all of your prescribed medications at the right dose intervals and in the correct dosage.

The difficulty is distinguishing the above type of insignificant 'blip' from real virologic failure. In general, a blip is 50-500 copies/ml and temporary, so that when repeated, the viral load returns to below the level of detection. True virologic failure is usually a higher value (above 1,000 c/ml) and continues to rise, and is more often associated with drug resistance, falling CD4 cells, and new opportunistic infections.

In your case, you have good reason to think that this event is a blip. You should take steps to ensure that you are doing everything you can to take all of your ART medications as prescribed without lapses, and you should see your doctor ASAP for repeat viral load, CD4 cell, and resistance testing. And I urge you to talk to your doctor about your concerns and this response.