Effectiveness of isoniazid treatment for latent tuberculosis infection among human immunodeficiency virus (HIV)-infected and HIV-uninfected injection drug users in methadone programs.

Injection drug users (IDUs) were heavily affected by the tuberculosis (TB) resurgence in New York City in the 1990s. We assessed the effectiveness of screening for latent TB infection in methadone users and of selective treatment with isoniazid. Risk for future TB was classified as low or high on the basis of tuberculin, anergy, and HIV test results. The cohort of 2212 IDUs was followed up for a median of 4.2 years; 25 IDUs, of whom 20 (80%) were infected with human immunodeficiency virus (HIV), developed TB. In an adjusted Cox proportional hazards model of high-risk IDUs, the risk of TB was associated with HIV infection (HR 10.3; 95% CI, 3.4-31.3); receipt of <6 months of isoniazid therapy (HR 7.6; 95% CI, 1.02-57.1); a CD4+ T lymphocyte count of <200 cells/mm3 (HR 6.6; 95% CI, 1.7-25.9); and tuberculin positivity (HR 4.0; 95% CI, 1.6-10.2). Treatment with isoniazid was beneficial in HIV-infected, tuberculin-positive IDUs.

Tuberculin testing and risk of tuberculosis infection among New York City schoolchildren.

OBJECTIVES: To assess adherence to a 1996 health policy change, which discontinued mandatory tuberculin skin testing (TST) of new entrants to NYC primary schools and continued mandatory testing of new entrants to secondary schools. METHODS: The proportion tested before (1991-1995) and after (1996-1998) the change in health policy was determined. Factors associated with TST positivity and the cost of continued testing were assessed. RESULTS: A total of 76.6% of 551 636 new entrants to primary schools were tested in 1991-1995; slightly fewer, 71.1% of 339 958, were tested in 1996- 1998. Among new entrants to secondary schools, 31.0% of 106 463 were tested in 1991-1995 and 51.4% of 53 762 were tested in 1996-1998. The proportion who were TST-positive continued to decrease after 1996 to 1.2% among primary and 9.7% among secondary schoolchildren in 1998. Older age and birth outside the United States were associated with TST positivity. The estimated minimum cost of continued testing in primary schools was $123 152 per tuberculosis case prevented. CONCLUSION: An approach aimed at reducing testing of children at low risk for latent tuberculosis infection did not decrease testing of younger children. More important, older children who were more likely to be born in countries of high tuberculosis incidence were not tested. Additional efforts are needed to increase awareness among medical and school personnel to decrease testing among children who do not have risk factors for latent tuberculosis infection and to increase tuberculin testing of children who are entering school for the first time at the secondary level and do have risk factors for tuberculosis infection.