[1] Univ Peruana Cayetano Heredia, Lima, Peru
[2] USN, Med Res Ctr Detachment, Lima, Peru
[3] US Mil HIV Res Program, Rockville, MD USA
[4] Henry M Jackson Fdn, Rockville, MD USA
[5] Univ Nacl Mayor San Marcos, Sch Vet Med, Lima 14, Peru
[6] Ctr Dis Control & Prevent, Natl Ctr Infect Dis, Div Parasit Dis, Immunol Branch, Atlanta, GA USA
[7] Johns Hopkins Univ, Bloomberg Sch Publ Hlth, Dept Int Hlth, Baltimore, MD USA