Neighborhood socioeconomic position and tuberculosis transmission: a retrospective cohort study
1 Division of Epidemiology & Biostatistics, University of Arizona, Tucson, AZ, USA
2 Department of Epidemiology, University of Washington, Seattle, WA, USA
3 Public Health-Seattle & King County Tuberculosis Control Program, Seattle, WA, USA
4 Division of Pulmonary and Critical Care Medicine, University of Washington, Seattle, WA, USA
BMC Infectious Diseases 2014, 14:227 doi:10.1186/1471-2334-14-227Published: 27 April 2014
Current understanding of tuberculosis (TB) genotype clustering in the US is based on individual risk factors. This study sought to identify whether area-based socioeconomic status (SES) was associated with genotypic clustering among culture-confirmed TB cases.
A retrospective cohort analysis was performed on data collected on persons with incident TB in King County, Washington, 2004–2008. Multilevel models were used to identify the relationship between area-level SES at the block group level and clustering utilizing a socioeconomic position index (SEP).
Of 519 patients with a known genotyping result and block group, 212 (41%) of isolates clustered genotypically. Analyses suggested an association between lower area-based SES and increased recent TB transmission, particularly among US-born populations. Models in which community characteristics were measured at the block group level demonstrated that lower area-based SEP was positively associated with genotypic clustering after controlling for individual covariates. However, the trend in higher clustering odds with lower SEP index quartile diminished when additional block-group covariates.
Results stress the need for TB control interventions that take area-based measures into account, with particular focus on poor neighborhoods. Interventions based on area-based characteristics, such as improving case finding strategies, utilizing location-based screening and addressing social inequalities, could reduce recent rates of transmission.