Michel L. Bunning*†‡ , Richard A. Bowen§, C. Bruce Cropp†, Kevin G. Sullivan†, Brent S. Davis†, Nicholas Komar†, Marvin S. Godsey†, Dale Baker§, Danielle L. Hettler†, Derek A. Holmes†, Brad J. Biggerstaff†, and Carl J. Mitchell†

Author affiliations: *Centers For Disease Control and Prevention, Atlanta, Georgia; †Centers For Disease Control and Prevention, Fort Collins, Colorado, USA; ‡United States Air Force; §Colorado State University, Fort Collins, Colorado, USA