tuberculosis in United States

The United States has a considerably lower prevalence of infection, with recent Centers for Disease Control and Prevention (CDC) estimates suggesting that only 4 to 6% of the population (10 to 15 million persons) harbor latent infections. Case rates in the United States fell consistently from 1953 to 1984, but there was a substantial upsurge in 1985 to 1992. Elements feeding this increase included human immunodeficiency virus (HIV) infection, immigration, and most significantly, deterioration of the public health infrastructure. After treatment programs were strengthened and measures were taken to reduce nosocomial transmission, case rates dropped from 10.5 per 100,000 in 1992 to 4.9 per 100,000 in 2004, with an all-time low of 14,571 cases in 2004.

Among Americans of color, tuberculosis is largely a disease of young adults, with the peak incidence between the ages of 25 and 44 years. By comparison, the peak age in whites is 70 years and older, presumably because of reactivation of latent infections from early in life. In 2004, 53% of U.S. tuberculosis cases occurred in immigrants, and nearly another 30% occurred in U.S.-born minority populations. When compared with the 2004 case rate for the white population in the United States (1.3 cases per 100,000 persons per year), the relative risks were 8.3 for African Americans, 7.5 for Hispanic Americans, and 20 for Asian/Pacific Islanders. Within these three groups, foreign-born individuals accounted for 27% of cases in African Americans, 74% of cases in Hispanics, and 95% of cases in Asian/Pacific Islanders. The case rate for foreign-born persons (25.3) is now 10-fold higher than that for persons born in the United States. Major sources of these cases include Mexico, the Philippines, Southeast Asia, the Caribbean, and Latin America.