Drug susceptibility pattern of Mycobacterium tuberculosis in adult patients with miliary tuberculosis

Miliary tuberculosis (TB) is a fatal form of TB. Although drug resistance in TB patients has increased worldwide, there is limited information on drug resistance in miliary TB. This study from Pakistan evaluated drug susceptibility pattern among miliary TB patients of a high TB-burden country. All adult patients with miliary TB, admitted between 1994 and 2001, were identified using a computerized database. Culture-positive isolates were evaluated for drug susceptibility using middle brook 7H10 agar according to National Committee for Clinical Laboratories Standard criteria. Of 110 patients diagnosed with miliary TB, 32 (30%) were culture positive (yielding 35 culture isolates). The sources of positive cultures were sputum (37%), cerebrospinal fluid (18%), lymph nodes (12%), bone marrow (9%), bronchial wash (9%), urine (6%), lungs (6%) and liver (3%). Isoniazid resistance was found in three (9%) isolates. All the isolates were sensitive to rifampicin, ethambutol, pyrazinamide and streptomycin. Despite a worldwide increase in TB drug resistance, patients with miliary TB have infection with drug-sensitive mycobacterium. First-line anti-TB drugs should be used as initial therapy in miliary TB patients.