Abstract

Hookworm infections remain a significant public health concern in tropical and subtropical regions, including Thailand. This study investigated the species and genetic diversity of hookworm infections in domestic dogs from northeastern Thailand. The molecular analysis focused on amplifying and sequencing specific regions of ribosomal RNA genes (ITS1-5.8S-ITS2 region) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene in hookworm larvae recovered from 21 domestic dog stool samples. Among 21 larvae (one larva per infected dog) analyzed, 14 had sequences identical to Ancylostoma caninum, and 7 showed sequences almost identical to Ancylostoma ceylanicum. Phylogenetic analysis of cox1 sequences placed A. caninum and A. ceylanicum in separate clades. The median-joining network of A. caninum cox1 sequences from Thailand showed high haplotype diversity and belonged to the same cluster as sequences from Australia while forming separate clusters from those of A. caninum samples from the USA. The available published A. ceylanicum cox1 sequences (n = 33), in combination with seven sequences in the present study, represented 15 haplotypes distributed among three clusters. Interestingly, A. ceylanicum sequences from dogs and humans shared the same haplotypes. These findings are crucial for recognizing the potential for zoonotic transmission, highlighting the necessity for targeted control measures, and increasing awareness among pet owners and healthcare professionals to mitigate the risk of hookworm transmission to humans.