Mycobacterium avium Complex (MAC)

November 2004     View PDF     En español

Symptoms

The most common symptoms of MAC are persistent fevers plus night sweats, loss of appetite, weight loss, tiredness or worsening diarrhea. Symptoms of early disease often involve the gut: stomach cramps, nausea and vomiting. Disseminated disease can lead to bone, brain or skin infections, or cause painful joints.

Signs of MAC include swollen abdominal lymph nodes, usually on only one side of the body, and an enlarged liver and spleen. Coughing and wheezing are less common. Since many of these symptoms are similar to symptoms of other opportunistic infections (OIs), it’s important to get a correct diagnosis before you start treatment. If you have symptoms like these, talk to your doctor.

A recent study showed that people who already have MAC when they start potent anti-HIV therapy sometimes have an unusual response. It has been called MAC reversal syndrome and results from improved immune function (increases in CD4+ cell counts). It involves fevers and the growth of lumps usually around the neck or spine. The drug prednisone can reduce these symptoms.

Over time, these people still benefit from anti-HIV therapy and their MAC infection stabilizes. So anti-HIV therapy does not always stop MAC in people with early MAC infection, but overall it seems to be beneficial whether or not MAC occurs. However, it may be useful to screen for MAC in people with symptoms like fevers before they start anti-HIV therapy.