Dear Dr. Sherer, I just had a question concerning cd4 levels and a viral load. Why is it that people who are first diagnosed with hiv t-cells are so low? and why do they vary so much? Some people posts state that they have such low numbers like "23". Is this because they waited to long to check the hiv checked? or does the virus kill t cells rapidly?

Thanks a lot

There are several possible reasons. Often people infected with HIV are unaware of their diagnosis, and either they are unaware of their risk of HIV, or they ignore or deny it and don't get tested. So their first HIV test is done when they first get sick and their CD4 cells are usually below 200, or even lower.

Two thirds of patients are 'slow progressors' who have a slow decline in CD4 cells of around 100/year. They take 10 or more years to get to the level of 200 cells or less, and so have more time to get a positive HIV test at a higher level. One third are 'rapid progressors' who can progress to low CD4 cell levels within 1-5 years.

There is little evidence that one strain of HIV is more virulent than others.

The lesson for all of us from this is that any degree of HIV risk should prompt an HIV test, so that the disease can be diagnosed earlier, and the person can have more options for treatment at an earlier stage.