In HIV, your CD4 count is key. It's the most important measure of your immune system's health. When it's high, you're in good shape. But when it's low, you're at risk for developing a number of potentially dangerous illnesses. These illnesses are generally known as "opportunistic infections," or OIs for short.
Are You At Risk?
The danger zone for your CD4 count is around 200. If your CD4 count goes below this level (or your CD4 percentage dips below 14%), your doctor may recommend that you start taking some medications in addition to starting HIV meds. These other medications are meant to prevent opportunistic infections from taking advantage of your weakened immune system. Doctors use the word "prophylaxis" to describe these medications.
The most common type of drug used in this way is called Bactrim (it also goes by the names TMP-SMX, Septra, Sulfatrim and co-trimoxazole). Bactrim is an antibiotic; its chief mission is to prevent you from developing a potentially life-threatening form of pneumonia known as Pneumocystis pneumonia, or PCP. Bactrim can also protect you against another OI: toxoplasmosis. This is a parasite that is sometimes found in cat feces or raw meat.
There are other medications your doctor may prescribe you to prevent various OIs from developing while your immune system is weak. There are also a range of vaccinations experts recommend for people with HIV, especially if you have a low CD4 count. And finally, there are many simple things you can do to protect yourself from getting new infections, including washing your hands often (especially if you have pets), being caeful about the water you drink and avoiding raw eggs, meats and shellfish, and taking extra precautions when you travel (particularly if you're visiting a developing country).
Already Have an Opportunistic Infection?
Many people only find out they HIV once they already have a low CD4 count and have begun to develop opportunistic infections. Fortunately, there are ways to treat these opportunistic infections. The best way is usually to begin taking HIV medications; once you start taking meds, your CD4 count will go up, your immune system will become stronger, and you'll be more able to fight off OIs.
There are meds that can help you fight off some OIs, however. In the case of PCP, for instance, the same drug that people take to prevent it -- Bactrim -- can also be used to treat it. Depending on the OI, your doctor may prescribe one or more drugs meant to beat back the infection and help your immune system recover.
CD4 Count Explained
||500 - 1,660
||350 - 500
||200 - 350
||0 - 200
To Learn More
For more info on protecting yourself from opportunistic infections, or treating an opportunistic infection if you have one, visit these pages: