Isoniazid-resistant Mycobacterium kansasii in an HIV-positive patient, and possible development of immune reconstitution inflammatory syndrome after initiation of highly active antiretroviral therapy: case report

Non-tuberculous mycobacteria are rare but important causes of infection in HIV-positive individuals. A 28-year-old HIV-positive male presented with a high fever, non-productive cough, right subcostal pain, splenomegaly, a very low CD4 count, elevated C-reactive protein and erythrocyte sedimentation rate, and a normal white blood cell count. The suspicion of tuberculosis (TB) was very high, and sputum samples were positive for acid-fast bacilli. Standard quadruple anti-TB therapy was initiated, but once culture of the sample revealed Mycobacterium kansasii, pyrazinamide was withdrawn. Highly active antiretroviral therapy (HAART) was initiated soon after, consisting of abacavir/lamivudine and efavirenz. The patient's general condition deteriorated 2 weeks after HAART initiation, which could have been due to the development of immune reconstitution inflammatory syndrome (IRIS). The patient recovered and was discharged in good condition. However, the results of resistance testing of the isolated organism arrived after discharge, and showed isoniazid and streptomycin resistance. This is the first case report of M. kansasii infection from Serbia and shows the difficulties encountered during the course of treatment.