Tuberculosis transmission and use of methamphetamines in Snohomish County, WA, 1991-2006

Abstract

Objectives: We investigated a cluster of tuberculosis (TB) cases among persons using methamphetamines in Snohomish County, Washington, to determine the extent of the outbreak, examine whether methamphetamine use contributed to TB transmission, and implement strategies to prevent further infections.

Methods: We screened contacts to find and treat persons with TB disease or infection. We then formed a multidisciplinary team to engage substance abuse services partners and implement outreach strategies including novel methods for finding contacts and a system of incentives and enablers to promote finding, screening, and treating patients with TB and their infected contacts.

Results: We diagnosed and completed treatment with 10 persons with TB disease. Eight of 9 adult patients and 67% of their adult contacts reported using methamphetamines. Of the 372 contacts, 319 (85.8%) were screened, 80 (25.1%) were infected, 71 (88.8%) started treatment for latent infection, and 57 (80.3%) completed treatment for latent infection.

Conclusions: Collaborative approaches integrating TB control, outreach, incentives, and enablers resulted in high rates of treatment adherence and completion among patients and infected contacts. TB control programs should collaborate with substance abuse programs to address addiction, overcome substance abuse-related barriers to treatment, treat TB, and prevent ongoing transmission.

FIGURE 1

Social link between past and current TB outbreaks: Snohomish County, WA, 1991–1999 and 2005–2006. Note. TB = tuberculosis. Patients inside the ovals used drugs at the Shack. Patient in dark box labeled A was infected during the 1991–1999 outbreak, did not complete prophylactic treatment, and later developed and was treated for TB disease in 2002. Patients in boxes connected to Contact/Patient A represent a link between the 1991–1999 and 2005–2006 outbreaks.