RESUMEN
PURPOSE: The aim was to characterize the infection by Trichostrongylus spp. in patients from Chile using a combination of molecular detection techniques and phylogenetic analysis relating the findings to clinical and epidemiological reports of the patients METHODS: Strongylid eggs were detected in seven patients by coproparasitological techniques. From each sample a fragment of the ITS-2 ribosomal gene was amplified by PCR, sequenced and analyzed by the Neighbor-Joining method. RESULTS: All the sequences and phylogenetic clusters corresponded to T. colubriformis. Two samples presented a single nucleotide polymorphism showing two possible haplotypes. Six patients presented gastrointestinal symptoms. All of them lived on farms and used sheep manure as fertilizer. CONCLUSION: T. colubriformis was the strongylid involved in the infections of these Chilean patients associated with the presence of livestock and agricultural practices that favor infection by this type of nematode.