During January 1994–December 2007, Programa Juntos treated 613 patients with smear-positive pulmonary TB. Forty-eight (7.8%) patients had MDR-TB; all were born in Mexico. Of these patients, 35 (73%) were male, their mean age was 45 years, and 37 (77%) had a history of TB. Sixteen (33%) patients had concomitant medical conditions; 13 had diabetes and 1 each had silicosis, aplastic anemia, and renal failure, respectively. All patients were negative for HIV infection.
Patients were resistant to a mean of 3.75 drugs. Thirteen (27%) patients had isolates with resistance to ethambutol, 10 (21%) with resistance to pyrazinamide, 19 (40%) with resistance to streptomycin, 11 (23%) with resistance to ethionamide, 25 (52%) with resistance to rifabutin, and 2 (4%) with resistance to ofloxacin. No isolates were found to be resistant to kanamycin, amikacin, capreomycin, or cycloserine. Thus, no cases of extremely drug resistant TB were found.
Of 48 patients with MDR-TB, 2 were transferred to another facility at their request. Of the remaining 46 patients, 30 (65%) were cured according to our definition, 2 (4%) had treatment failure, 3 (6%) died during treatment, and 11 (24%) defaulted; 4 left the study before starting treatment and 5 left the study within the first 6 months of therapy. Clinical characteristics of patients are shown in .
Characteristics of patients with multidrug-resistant tuberculosis, El Paso, Texas*
Patients were given regimens with a median of 5 drugs (range = 4–7 drugs). Mean duration of treatment was 14 months (range = 1–27 months). Among the 42 patients given second-line drugs, these regimens included fluoroquinolones for 41 patients (ciprofloxacin for 20 patients, levofloxacin for 20 patients, and ofloxacin for 1 patient); amikacin for 31 patients; ethambutol for 20 patients; pyrazinamide for 11 patients; capreomycin for 31 patients; streptomycin for 5 patients; ethionamide for 18 patients; cycloserine for 31 patients; and clofazimine, kanamycin, and para-aminosalicylic acid for 1 patient.
Among 30 patients with a final outcome of cured, the proportion of patients with negative acid-fast bacilli sputum smears was 12 (40%) after one month of treatment, 20 (67%) after two months of treatment, and 24 (80%) after three months of treatment. The proportion of patients with negative TB culture was 8 (27%) after one month of treatment, 11 (37%) after two months of treatment, and 18 (60%) after three months of treatment.
Two patients were considered to be treatment failures. These patients had persistent positive sputum smears and cultures after 12 months of therapy despite receiving 4 medications with known in vitro activity. Both patients were receiving regimens that included ciprofloxacin (1 gram), capreomycin (1 gram), cycloserine (500 mg), and ethionamide (500 mg).