[1] NIAID, INFECT DIS LAB, BETHESDA, MD 20892 USA
[2] OHIO STATE UNIV, OHIO AGR RES & DEV CTR, WOOSTER, OH 44691 USA
[3] ISHIMARU CHILDRENS HOSP, MATSUYAMA, EHIME 790, JAPAN
[4] EHIME PREFECTURAL INST PUBLIC HLTH, MATSUYAMA, EHIME 790, JAPAN
[5] MATSUYAMA PREFECTURAL INST PUBLIC HLTH, MATSUYAMA, EHIME 790, JAPAN