Hien TT, Liem NT, Dung NT, San LT, Mai PP, Suu PT, Chau NVV, Mai LTQ, Thi NT, Khoa DB, Phat LP, Truong NT, Long HT, Giang LT, Tho ND, Long HT, Tien NTK, San LH, Tuan LV, Dolecek C., Thanh TT, Jong MD, Schultsz C., Cheng P, Lim W, Horby P for the WHO International Avian Influenza Investigative Team, and Farrar JJ