Pulmonary tuberculosis outbreak in a pediatric population.

Community-based outbreaks of Mycobacterium tuberculosis are uncommon in the United States but represent a dramatic type of epidemic that can lead to considerable investigations. Most of our knowledge regarding spread of tuberculosis (TB) has accumulated from the study of outbreaks. We describe the most recent outbreak of TB in Genesee County, Michigan. In February 2007, isoniazid-sensitive infectious pulmonary TB was identified in a 45-year-old African American grandmother who frequently provided care for her grandchildren and other children. The source case was reported to the Genesee County Health Department, which started an investigation to identify family and social contacts. We reviewed past medical records of contacts and prioritized them for evaluation based on the period of exposure to the index case. Health department staff screened contacts using clinical evaluation, tuberculin skin test, and chest radiography when indicated. Results were reviewed, and data were analyzed using descriptive inferential and epidemiological statistics.