Fig 3. The haplotype networks of cox1 and nad1 sequences of O. viverrini isolated from three villages in central Thailand, reference isolates from Thailand, Lao PDR, Vietnam and Cambodia.

(A) The haplotype network of 29 haplotypes based on cox1 sequences. Haplotype M contains 20 isolates and shows highest frequency; seven isolates from Thoong-Heang Village (TH), 12 isolates from Na-Ngam Village (NN), and one isolate from Lao PDR. Twenty two singletons are obtained as shown in smallest circles; 10 singletons (Haplotype B, D, E, F, G, H, I, J, K and L) from Na-Yao Village (NY), seven singletons (Haplotype N, O, P, Q, R, S, and T) from Na-Ngam Village and five singletons (V, W, Y Z and A1) from Thoong-Heang Village. The reference isolates from Thailand and Lao PDR are grouped in Haplotype B1 and C1. (B) The haplotype network of 31 haplotypes using nad1 sequences. Haplotype G presents the highest frequency of 9 isolates; 7 isolates from Na-Ngam Village, one isolate from Na-Yao Village and one isolate from Lao PDR. Twenty singletons are demonstrated; seven singletons (Haplotype B, C, D, E, F, H and I) from Na-Yao Village, three singletons (Haplotype I, K, M and N) from Thoong-Heang Village, four singletons (Haplotype O, P R and S) from Na-Ngam Village, five singletons (Haplotype T, U, V, Y and Z) from Vietnam and one singletons (Haplotype E1) isolate from Lao PDR. The reference isolates from Thailand, Lao PDR, Vietnam and Cambodia are clustered in Haplotype X, A1, B1, C1 and D1. Each open circle represents each haplotype and the numbers of each haplotype were placed in parentheses. Each singleton is marked with the names for villages and isolates. The solid line shows the network relationship of the haplotypes. The frequency of nucleotide change between haplotypes is shown as black bullets.