Patterns of Mycobacterium avium Culture and PCR Positivity in Immunodeficient HIV-infected Patients: Progression from Localized to Systemic Disease

Our aim was to establish the frequency and the longitudinal pattern of MAC culture positivity in late stage HIV-infected patients. Two other aims were to analyse risk factors for progression from localized to systemic disease and the value of PCR diagnosis using blood specimens, A total of 107 patients were recruited to be followed for 32 seeks. Prior MAC treatment and CD4 > 100/mu l were exclusion criteria. A total of 56 patients showed M., avium in at least 1 culture. 10/37 patients with MAC detected by culture first in 'non-sterile' specimens (stool, sputum) and urine progressed to systemic disease as determined by positive blood culture. Risk factors associated with this progression vr ere a high symptom score at baseline, lymphadenopathy, anaemia, and low platelets. PCR was less sensitive than culture in detection of M. avium in blood specimens: Only 7/29 patients with positive blood cultures had a positive PCR at the same time. We conclude that symptomatic patients with advanced HIV-infection hale a high frequency of MAC detection. Progression from localized to systemic culture positivity is associated with risk factors. Early 'pre-emptive' therapy is discussed.