HIV drug resistance threshold survey using specimens from voluntary counselling and testing sites in Hanoi, Vietnam. by Nguyen, H, Duc, N, Shrivastava, R, Tran, T, Nguyen, T, Thang, P, McNicholl, J, Leelawiwat, W, Chonwattana, W, Sidibe, K, Fujita, M, Luu, C, Kakkar, R, Bennett, D, Kaplan, J, Cosimi, L, Wolfe, M