Dear Dr. Young, I have written several questions in relation to my partners HIV status and am still waiting for someone to reply, My partner was diagnosed in june of this year with a CD4-t count of 50 and a viral load of 500,000 if i remember correctly. The doctors and my parner have traced the date of infection to around 4 years ago (At this point my partner was injecting Heroin and assumes sharing a needle to be the point of infection). My partner has been on treatment for 3 months (sustiva, epivir, viread and septrim) and doctors say he is responding well although it is still very early. My concern here is that even though he quit Heroin over a year ago (occasionally smokes it) and takes methadone daily, since becoming aware of his HIV+ status he has ben regularily smoking crack cocaine, 1-2 rocks 3 times aweek and has also started smoking marijuana on a daily basis. What effect will this have on his treatment? we live in the UK and although he has been offered a counselling service at the hospital, he will not discuss his drug habitys with the doctor or anyone other than myself. We have been together for almost 3 years and amazingly i have not been infected through unprotected sex and am almost 8 months pregnant. We have evything to look forward to but I cannot stop worrying about this habit and if it's stopping his treatments from working. Also please tell me his life expectancy, could it realistically be over 20 years??? Yours, desperately!! Alison, UK

Allison, thanks for your question.

It is good to hear from international readers.

The essential issue for anyone on HAART regimens is the ability to adhere to the treatment with as few missed doses as possible. This is my priniciple concern for those who have active drug dependencies- whether cocaine or heroin. To my knowledge, there isn't any particular drug-drug interaction that might make your partner's treatment regimen less potent, only is issue that binge substance abuse might make someone less apt to be able to fully adhere to the treatment regimen.

With a CD4 count of 50 your partner's situation is very serious, and treatment failure can have catastrophic implications because of the risk of drug resistance and further diseaes progression. That said, recent analyses of several clinical trials tells us that persons with low CD4 cell counts can and do have dramatic improvements in their health and CD4 counts if they're able to remain adherent to treatment. If this is achieved, then life expectancy should be very long-- decades perhaps, and too difficult to predict with accuracy (though many would like us to tell them, to the day).

With best wishes for a healthy and happy child, BY