Session: Poster Session: Resistance in Mycobacteria
Monday, October 27, 2008: 12:00 AM
Room: Hall C
Background: TB therapy without isoniazid (INH) necessitates using medications with greater side effects, increased cost and lower efficacy. Treatment outcomes of INH-monoresistant (INHr) patients are not well described. Methods: Culture-confirmed NYC patients with primary INHr TB or drug-susceptible TB, diagnosed from 1995-2005 were reviewed. Demographic and clinical data were abstracted from the NYC TB registry. Results: There were 12,419 TB patients with drug susceptibility results; 1,361 (11%) isolates were INH resistant±other drugs, 582 (5%) were INHr, and 9,767 (79%) were drug-susceptible. INHr TB cases did not decline over the study period (ptrend=0.05). The median age of INHr patients was 40 vs. 42 years for patients with drug-susceptible isolates (p<0.001); 64% of INHr patients were male. Patients with INHr were more likely to be non-US-born (OR=2.0; 95%CI, 1.6-2.4) and Asian (OR=1.8; 95%CI, 1.3-2.5). Non-US born patients with INHr increased over the study period, from 60% to 87% (ptrend<0.001). INHr patients were more likely to be from Asia (OR=2.3;95%CI,1.8-2.8), Africa (OR=2.0;95%CI,1.3-2.9), and Latin America/Caribbean (OR=1.8;95%CI,1.4-2.2) than patients with drug-susceptible isolates. The median treatment length for INHr patients was 10 vs. 8 months for those with drug-susceptible isolates (p<0.001). INHr patients took >1 year to complete treatment (OR=1.6;95%CI,1.3-2.1). Among INHr patients, 82% completed treatment, 9% died, 4% were lost or refused treatment, and 4% transferred. Among drug-susceptible patients, 80% completed treatment, 14% died, 3% were lost or refused treatment and 2% transferred. Conclusions: INHr disproportionately affects non-US-born and Asian patients. Although NYC TB completion rates were high, INHr patients were treated longer than drug-susceptible patients. With increasing TB incidence among non-US born, the proportion of INHr cases may increase.