Isolation of Mycobacterium tuberculosis with primary resistance to chemotherapeutic agents in patients with HIV infection

A retrospective study of drug resistance of Mycobacterium tuberculosis in patients simultaneously affected by tuberculosis (TB) and HIV was conducted in a Spanish university hospital. 39 of the 287 patients (13.6%) were also HIV seropositive. Mycobacterium tuberculosis with primary resistance to at least one of the major antitubercular drugs was isolated in 4 of the 39 (10.3%). The 4 patients (3 males 1 female) demonstrating primary drug resistance were intravenous drug users aged 23-30 years. 3 were resistant to isoniazid 1 to rifampin 1 to streptomycin and 1 to pyrazinamide. None was resistant to ethambutol. 2 were resistant to one drug and 2 were resistant to 2 drugs. Resistance to streptomycin in 1 patient may have been secondary to treatment with aminoglucosides for endocarditis. It is recommended that diagnostic suspicion of TB be maintained in management of HIV infected patients because of the possibility of drug resistance and of in-hospital transmission. Shortened or simplified treatment regimens should be avoided in seropositive patients.