Neighborhood Poverty and the Resurgence of Tuberculosis in New York City, 1984-1992

The resurgence of tuberculosis in New York City in the 1980s and early 1990s was due to a group of factors that included AIDS, immigration, injection drug use, multi-drug resistance, homelessness and nosocomial transmission, as well as a breakdown in public health measures. As TB incidence grew from 1,307 cases in 1978 to 3,811 cases in 1992, the poverty rate between 1979 and 1993 increased from 11.7 percent to 15.1 percent nationally, and the rate in New York City went from 19.3 percent to 27.3 percent.

Poverty has traditionally been a risk factor for TB. However, in an area with high rates of AIDS and immigration, the contribution of poverty to TB risk may be overlooked. The authors of this study investigated whether poverty remained a major risk factor for TB at the peak of the NYC TB epidemic. An analysis of the longitudinal association of changes in poverty with changes in TB incidence was also performed.

For both analyses, neighborhoods as the unit of analysis were used and defined by census block group. A block group has a median population of approximately 1,000 and covers approximately 4 city blocks. The cross-sectional analysis included all block groups in NYC contained in the 1990 census with some limitations due to unstable populations (n=<5,785). The longitudinal analysis included all block groups listed in the 1980 census (n=<5,997). The 1980 and 1990 data listed population demographics for each block based on 100 percent sampling: socioeconomic data, including poverty, median household income, and place of birth. Incident cases of TB consisted of all notifications to the Bureau of Tuberculosis Control of newly diagnosed, culture-positive, or Centers for Disease Control and Prevention (CDC)-defined TB in NYC for 1984 (first year for which reliable data were available) and 1992. Of the 3,811 cases of TB in 1992, 3,503 (91 percent) were successfully matched to census block groups. Of these, 160 were matched to neighborhoods with a hospital, prison, homeless shelter or population of fewer than 100 persons, leaving 3,343 cases (87.7 percent) in the analysis. Homeless persons with TB were eliminated de facto by lack of a street address. Of the 1,630 cases of TB in 1994, similar proportions were excluded, leaving 1,379 cases (84.6 percent) in the analysis.

The results of the study indicated that the incidence of TB in 1992 in the 5,482 neighborhoods was 46.5 per 100,000 persons, and the mean rate of poverty across these neighborhoods was 19.3 percent. In general, the authors found, from 1980 to 1990, the rate of new TB cases grew as the average neighborhood income dropped. Other results included the fact that concurrent HIV infection was higher among US-born persons with TB than among foreign-born persons with TB. Citywide, TB incidence was higher among persons born in the United States than among the foreign-born (47.9 per 100,000 vs. 40.6 per 100,000, p<.001). People living in low-income neighborhoods had a significantly higher TB risk with each 10 percent decrease in income, increasing the relative risk by a factor of 1.36. In fact, neighborhood income was the factor most strongly associated with TB risk, and poverty was more closely linked to TB risk than HIV status, race or ethnicity.

According to the authors, the introduction of directly observed therapy and other interventions in homeless shelters, prisons and hospitals have reduced the burden of TB in NYC since 1992. However, it is unlikely that the association of TB with poverty will disappear, given the spread of AIDS into impoverished neighborhoods and reductions in government spending that continue in 2001. "Ultimately, as TB control programs become victims of their own success, priority should be given to impoverished neighborhoods."

Back to other CDC news for November 5, 2001

Previous Updates