An epidemiological and social network analysis to assess transmission during a tuberculosis homeless shelter outbreak in San Joaquin County

Tuberculosis (TB) is one of the most deadly diseases worldwide. In the United States, TB disproportionately affects foreign-born individuals, individuals living in congregate settings, people with human immunodeficiency virus, and people who use illicit drugs. In 2005, a large homeless shelter outbreak in San Joaquin County resulted in 67 individuals diagnosed with TB with links to a homeless shelter. It is hypothesized that by using bed analysis to identify contacts that have been exposed to TB during this outbreak will allow for better identification of exposed high-risk individuals than screening alone. Demographics, exposure, screening, and QuantiFERON-Tuberculosis results were analyzed using bed assignments from the homeless shelter database and data from a homeless shelter screening (HSS) program. Individuals diagnosed with active TB disease were on average more likely to be identified through bed analysis than HSS, 95.08% versus 59.02%. Utilizing both bed analysis and HSS allows for improvement of identification and continuous testing of individuals exposed to TB