Zip code-level risk factors for tuberculosis: neighborhood environment and residential segregation in New Jersey, 1985-1992

OBJECTIVES: This study examined zip code-level risk factors associated with very high tuberculosis (TB) rates among non-Hispanic Whites, African Americans, Hispanics, and Asians in New Jersey (1985-1992). METHODS: Exposure indices (poverty, crowded housing, and dilapidated housing) and segregation indices (contact with immigrants, isolation, and density) were used to characterize zip codes. A Boolean-logic methodology was used to determine which configurations of risk factors significantly distinguish zip codes where TB rates are very high from other zip codes. RESULTS: For Whites and Asians, risk factors were rare in zip codes with very high TB rates. In agreement with the distribution of TB cases by age and foreign-born status, this suggests that cases among Whites may be caused by reactivation, whereas cases among Asians may be imported. In contrast, Hispanics and African Americans were exposed to risk factors that may facilitate TB transmission. Among Hispanics, high contact with immigrants was an important factor. African Americans were the group most frequently exposed to multiple risk factors. CONCLUSIONS: For Hispanics and African Americans, zip code-level risk factors were associated with very high TB rates.