Substance Abuse Linked to Tuberculosis Transmission and Treatment Failure in the United States

Although tuberculosis (TB) prevalence is low in the United States, local outbreaks among people with substance abuse have been reported. Researchers from the Centers for Disease Control and Prevention analyzed records of all reported TB cases in the United States from 1997–2006 to assess the role of substance abuse in the transmission and treatment of TB.

• Of the 153,268 people with TB included in the analysis, 19% overall reported substance abuse (defined by self-reported excessive alcohol use, noninjection drug use, or injection drug use in the year before TB diagnosis). Of the 76,816 US-born TB cases, 29% reported substance abuse.

• Prevalence rates were higher for substance abuse than for other risk factors, including recent immigration to the United States, HIV infection, residing in a congregate setting, homelessness, or working at a high-risk occupation (e.g., healthcare, correctional-facility, or migrant worker).

• A TB-positive sputum smear was more common among people with substance abuse, both in persons with HIV infection (odds ratio [OR], 1.2) and without HIV infection (OR, 1.8).

• Treatment failure was more common among people with substance abuse, especially among women (OR, 2.4) but also among men (OR, 1.5).

• People with substance abuse were more likely to be in a county-level genotype cluster (defined as 2 or more patients from the same county with identical TB genotypes) (OR, 2.3).

Comments:

Substance abuse is seen in a minority of people in the US with TB. However, people with substance abuse and TB are more likely to be contagious, more likely to fail treatment, and more likely to be involved in a local outbreak. These findings support TB control interventions that focus on people who abuse substances. It is not clear from this study which specific substances or what severity of substance use were most associated with TB transmission— treatment failure or local outbreak.

Alexander Y. Walley, MD, MSc

Reference:

Oeltmann JE, Kammerer JS, Pevzner ES, et al. Tuberculosis and substance abuse in the United States, 1997–2006. Arch Intern Med. 2009;169(2):189–197.