[1] Uniformed Serv Univ Hlth Sci, Infect Dis Clin Res Program, Bethesda, MD 20814 USA
[2] USN, Infect Dis Clin, San Diego Med Ctr, San Diego, CA 92152 USA
[3] USN, Hlth Res Ctr, San Diego, CA 92152 USA
[4] Univ Minnesota, Div Biostat, Minneapolis, MN USA
[5] Walter Reed Natl Mil Med Ctr, Infect Dis Clin, Bethesda, MD USA
[6] San Antonio Mil Med Ctr, Infect Dis Serv, San Antonio, TX USA