The resurgence of tuberculosis (TB) in New York City in the period 197
8-92 has been closely linked to the AIDS epidemic but the increase of
active TB in areas of urban poverty also implies increased community e
xposure. We have examined the ecological relation between community ra
tes of AIDS and residential crowding and cases of active TB in Bronx c
hildren under age 5. Residential crowding was defined as the percent o
f households with more than 1 person per room. All childhood TB cases
reported between 1986 and 1992 for the Bronx (n = 75) were included. C
umulative AIDS mortality rates for adult females through 1990 represen
ted community HIV burden. All data were coded by the 64 health areas o
f the borough. We examined trends in these data and used Poisson regre
ssion to model the effect of HIV burden and residential crowding on TB
risk. For the Bronx as a whole the two variables of TB and residentia
l crowding showed a clear temporal correspondence for the period 1970-
90. Residential crowding was associated with poverty and greater depen
dence on public assistance, large household size, Hispanic ethnicity,
and a higher proportion of young children. The overall TB case rate in
creased with the proportion of crowded households, with a rise from 1.
47 to over 8 cases per 10 000 children as the proportion of crowded ho
useholds increased. At both the lowest and highest levels of AIDS mort
ality in these areas, the childhood TB risk increased as crowding incr
eased. Children living in areas of the Bronx in which over 12 percent
of homes are severely overcrowded were 5.6-fold more likely to develop
active TB, even after holding constant the presumed HIV burden in eac
h local community. While HIV infection, the newest risk factor for TB,
appears to play a critical role in the resurgent epidemic, our findin
gs show that the earliest known TB risk factors, poverty and household
crowding, are still potent forces.