I've been on Atripla for 4 years with no problems. I developed a M.R.S.A. infection and was prescribed Zyvox and a tetanus shot. Three weeks later when I did my blood work my viral load was 38000 and my Tcell count 1000. Can M.R.S.A./vacination account for the big change in numbers or could I be resistant to Atripla?

Both are possible. You and your doctor should repeat these studies promptly along with a genotype test to look for drug resistance, and you will answer that part of the question.

Intercurrent bacterial and viral infections and vaccinations are known to cause transient rises in viral loads, so that may also be an explanation. When your MRSA has been treated, the viral load should return to baseline if it was simply related to this infection. The degree of the increase in viral load, i.e. to 38,000, is concerning, so close follow up during this time is needed to answer this question.

I suggest that you talk to your doctor about your concerns and these responses.