Study concept and design: Chung, Buseman, Luby, Haley.
Acquisition of data: Chung, Buseman, Joyner, Hughes, Haley.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: Chung, Buseman, Joyner, Hughes, Fomby, Haley.
Critical revision of the manuscript for important intellectual content: Chung, Buseman, Joyner, Hughes, Luby, Haley.
Statistical analysis: Chung, Buseman, Joyner, Hughes, Fomby, Haley.
Administrative, technical, or material support: Chung, Buseman, Joyner, Hughes, Luby, Haley.
Study supervision: Chung, Haley.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Additional Contributions: We thank Taye Derse, MD, and Elizabeth Smith, RN (Dallas County Health and Human Services); Gene Lee, MPH, and Jeffery Lertdilok, MPH (University of Texas at Houston School of Public Health); and members of the Dallas County Medical Reserve Corps for assistance with case investigations. Scott Sawlis, MS, and Joey Stringer (Dallas County Health and Human Services) provided mosquito data from the Dallas County laboratory. Mary D’Anton and Grace Kubin, PhD, provided mosquito surveillance data on behalf of the Texas Department of State Health Services Laboratory Mosquito Surveillance Testing Team. Cindy Corley and Victoria A. Yeatts, MSN, RN (City of Garland Health Department) and Michael McElway and Shelley Stonecipher, DVM (Texas Department of State Health Services), provided additional data. Janet McAllister, PhD (Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Ft Collins, Colorado), provided entomological advice and assistance with calculation of the vector index. The above-mentioned contributors received no compensation for their work other than their usual salary.