Epidemiology of drug-resistant tuberculosis in New Jersey from 1991 to 1995

Abstract

Background: In a nationwide survey in 1991, the proportion of Mycobacterium tuberculosis isolates resistant to both isoniazid and rifampin (MDR-TB) in New Jersey (6.6%) was ranked second highest in the United States. The objectives of this study were to describe drug-resistant TB trend and to investigate risk factors for TB patients with isolates resistant to isoniazid or rifampin or both.

Methods: TB surveillance data in New Jersey from 1991-1995 were analysed. Data on Mycobacterium tuberculosis culture and drug susceptibility testing of all TB isolates were obtained from public health and clinical laboratories. Logistic regression was performed to calculate odds ratios (OR) and 95% confidence intervals (CI) and to adjust for potential confounders.

Results: From 1991 to 1995, the proportion of MDR-TB was 5.7%, 4.1%, 2.7%, 3.3% and 2.6%, respectively. There was 10.6% isoniazid resistance and 4.3% rifampin resistance among TB patients in 1993-1995. As expected, recurrent TB was the most important risk factor for resistance to isoniazid (OR = 4.5, 95% CI: 2.6-7.6), rifampin (OR = 5.5, 95% CI: 2.8-11) or both (OR = 6.1, 95% CI: 2.9-13). HIV infection was significantly associated with MDR-TB (OR = 3.6, 95% CI: 1.5-8.8). Drug resistance was not found to be significantly associated with homelessness, injecting drug use and excess alcohol use.

Conclusions: The proportion of MDR-TB in New Jersey declined significantly from 1991 to 1993, but remained at a plateau from 1993-1995. The results suggest that continuous efforts should be directed at the prevention of MDR-TB among people infected with HIV and at improving the proportion who complete chemotherapy among those with TB.