The association of housing density, isolation and tuberculosis in Canadian First Nations communities.

BACKGROUND

First Nations communities in Canada experience disproportionately high levels of overcrowded housing, degree of isolation, and rates of tuberculosis (TB). A study was done to assess the association between housing density, isolation, and the occurrence of TB in First Nations communities.

METHODS

Average persons per room (ppr), isolation type, average household income, population, and TB cases (1997-1999) at the community level were entered into a database. Tuberculosis notification rates and 95% CI were calculated for different strata of ppr and isolation. Two multiple logistic regression models were developed to examine the association of ppr, isolation, income, and population with the occurrence of >/=1, or >/=2, TB cases in a community.

RESULTS

The rate was 18.9 per 100,000 (95% CI: 13.3-24.6) in communities with an average of 0.4-0.6 ppr, while communities with 1.0-1.2 ppr had a rate of 113.0 per 100,000 (95% CI: 95.4-130.5). An increase of 0.1 ppr in a community was associated with a 40% increase in risk of >/=2 TB cases occurring, while an increase of $10,000 in community household income was associated with 0.25 the risk, and being an isolated community increased risk by 2.5 times.

CONCLUSIONS

This study shows a significant association between housing density, isolation, income levels, and TB. Overcrowded housing has the potential to increase exposure of susceptible individuals to infectious TB cases, and isolation from health services may increase the likelihood of TB.