My husband is HIV-positive. He has not needed to take medication, and his blood levels are very good. How worried should I be when he gets a cold or common illness? I tend to lose sleep when he is feeling a little under the weather.

I.T.

You have to find out the particulars of your husband's condition. As you know, HIV (the human immunodeficiency virus) is the virus that causes AIDS. There are two important values that we measure in the blood of HIV patients. The first is the viral load. This is the amount of virus that is present in the blood. The higher this number is, the more likely it is that the patient will progress to AIDS and death. Some patients have such a low viral load, even without treatment, that they do not progress at all for more than 10 years. The second value that we measure is the number of T-helper cells, or CD4 cells. These are the immune-system cells that are most affected by HIV. When the level of CD4 cells is low, the patient is at risk of various AIDS-related illnesses.

You need to find out what your husband's CD4 count is. Normal is about 1,000. A patient with HIV does not have much risk of an AIDS-related illness if his CD4 count is higher than 500. At this level, the risk of developing a complication from a cold or another simple common illness is probably not that much higher than the risk to someone without HIV. He would be at a little higher risk of typical bacterial pneumonia, but not enough risk to lose sleep over every time he has a cold. If his CD4 count is higher than 500, then you should just encourage him to see his physician sooner rather than later for the common illnesses.

If his CD4 count is less than 500, then he should be considered for treatment directed against HIV. (Generally, patients are treated with multiple drugs, the so-called "cocktail." These medications have been shown to prolong life and delay or prevent AIDS-related complications.) In addition, with a CD4 count less than 500, he would start to be at more risk of many different infections, including tuberculosis and pneumonia. If his CD4 count is less than 200, he is at risk of pneumocystis pneumonia (also called "PCP") and other very serious infections. If his level is less than 200, he should be taking specific medications to prevent some of these complications.

I also want to stress to you that as his wife, you are at risk of acquiring the infection through sex. Even if his blood levels are very good, you are at risk. There can even be transmission if his viral load (the amount of virus in his blood) is below the detectable level. The only absolute way to avoid infection is complete abstinence. Short of that, condoms are very effective, and I would urge you to use a condom every time you have sex with your husband.