TUBERCULOSIS OUTBREAK IN A TEXAS PRISON, 1994

In 1994 a Texas prison containing a population of mentally retarded in mates experienced a large tuberculosis outbreak. Fifteen cases of tube rculosis were identified (8 confirmed by positive cultures for Mycobac terium tuberculosis) and more than 100 inmates became infected. The cu lture-confirmed patients were infected with an identical strain of tub erculosis as demonstrated by polymerase chain reaction (PCR) based DNA fingerprinting technique. The prison followed standard tuberculosis i nfection control policies, but these controls were inadequate to preve nt tuberculosis transmission in this special population. Two hundred a nd thirty inmates (119 inmates showing evidence of new tuberculosis in fection or active disease and 111 healthy controls) were enrolled in t he investigation. Inmate cell assignments, job duties, and educational classes were identified and medical chart reviews were conducted on a ll inmates. Tuberculosis transmission was associated with residing on the D Wing of the prison (OR = 25.84, P < 0.01), attending school in C lassroom A (OR = 8.34, P = 0.01) and working on the prison utility wor k crew (OR = 2.52, P < 0.01). The index case in the outbreak had been prescribed 6 months of isoniazid (INH) chemoprophylaxis in 1988.