[1] USA, MED RES INST INFECT DIS, DIV VIROL, FREDERICK, MD 21702 USA
[2] UMEA UNIV, DEPT VIROL, UMEA, SWEDEN
[3] UNIV NEW MEXICO, DEPT PATHOL, ALBUQUERQUE, NM 87131 USA
[4] UNIV NEW MEXICO, DEPT MED, ALBUQUERQUE, NM 87131 USA
[5] ASAN INST LIFE SCI, SEOUL, SOUTH KOREA
[6] CTR DIS CONTROL, SPECIAL PATHOGENS BRANCH, ATLANTA, GA 30333 USA