Multiplex PCR in diagnosis of M. tuberculosis and M. avium co-infection from lymph node in an AIDS patient.

A 35-year-old, HIV-seropositive male (CD4 count 41 cells/mm3) on highly active antiretroviral ( HAART) presented with fever and weight loss for 3 months and new skin lesions. He was earlier diagnosed of TB and was on anti-tubercular therapy (ATT). The retroperitoneal lymph node aspirate showed acid-fast bacilli and epithelioid cell granulomas; however, cultures remained sterile. A dual infection with Mycobacterium tuberculosis and Mycobacterium avium was diagnosed with multiplex polymerase chain reaction (MPCR). Clarithromycin was added to ATT, and on follow-up at 1 and 3 months, the patient responded well. Molecular methods like MPCR should be exploited for routine diagnosis of high-risk patients.