Fever is a main symptom of MAC, along with night sweats, chills, weight loss, muscle wasting, abdominal pain, fatigue (often caused by anemia), and diarrhea. MAC can also cause enlargement of the liver and spleen, as well as the lymph nodes.
To diagnose MAC, blood and/or bone marrow samples are collected and sent to a lab for testing. To collect a sample of bone marrow, a doctor inserts a needle into the hip bone, usually near the top of the butt or the lower back. Collecting blood samples to look for MAC is no different from blood samples collected to check viral load or T-cell counts.
In order to check for MAC, the organisms must be "grown out" in test tubes. This can take approximately seven days, thus treatment – if MAC is suspected – is often started before a diagnosis is confirmed.