Lenght of HIV infection Nov 18, 2007

I had an HIV test March 2005 & 2006 both negative. HIV test 10/18/2007 results positive. The viral load was 61,091 & CD4 313. The expanded blood test came back today with viral load of 1,921 and a cd4 of 336. I am not on treatment waiting on the resistant test. Why would the VL drop? But also I am concerned that the cd is so low? Your thoughts on how long infected?

Response from Dr. Holodniy

Infection then could be as long as 18 months. It is possible it was more recent and you are seeing the viral load decline and the CD4 count low because of acute infection. You dont' indicate what the CD4% is. That could be a clue, in that if it's > 25% your counts will increase, but if < 20%, it is likely this is what your CD4 count will be. A normal CD4 count range is between 500-1500. Since we don't know usually get CD4 counts before HIV infection, we don't usually know what somebody's count is. So if you are starting around 500 and have acute HIV infection (where the count drops) your results would not be unexpected.

The decline in viral load could be the result of the acute infection process, where we usually see the viral load get very high and then decline over the first 6 months or so to a lower level, sometimes referred to as the viral setpoint. Your first viral load test could have caught the trend on the way down. The CD4 count could be low because of acute infection and will increase to some higher level over time once you immune system gets hold of the virus.