Discovery of a novel albendazole-ivermectin refractoryTrichurisspecies,T. hominis, in Côte d’Ivoire patients through fecal DNA metabarcoding

Albendazole-ivermectin combination therapy is a promising alternative to benzimidazole monotherapy for Trichuris trichiura control. We used fecal DNA metabarcoding to genetically characterize Trichuris populations in patients from a clinical trial showing lower albendazole-ivermectin efficacy in Côte d’Ivoire (ERR below 70%) than in Lao PDR and Tanzania (ERR above 98%). ITS-1 and ITS-2 rDNA metabarcoding revealed the entire Côte d’Ivoire Trichuris population was phylogenetically distinct from T. trichiura in Lao PDR and Tanzania, and more closely related to the porcine parasite Trichuris suis . Complete mitogenomes of eight adult Trichuris from Côte d’Ivoire confirmed their species-level differentiation. Corresponding Trichuris ITS-1 and ITS-2 sequences in NCBI from individual human patients in Cameroon and Uganda and three captive non-human primates suggest this newly recognized species, T. incognita , is distributed beyond Côte d’Ivoire and has zoonotic potential. Further work is needed to assess the impact of this Trichuris species on soil transmitted helminth control programs.