A One-Health Investigation of Zoonotic Parasites at the Human-Livestock-Wildlife Interface in the Chad Basin, Northeast Nigeria

The Chad Basin region of Northeast Nigeria represents a critical zoonotic transmission interface where human, domestic livestock, and wildlife populations interact intensively in a context of environmental degradation and humanitarian fragility. This doctoral study conducted a comprehensive one-health investigation of zoonotic parasitic diseases at the human-livestock-wildlife interface in Borno and Yobe states. A longitudinal design enrolled 400 human participants from fishing and farming communities, 300 domestic animals, and 120 wildlife specimens obtained through collaboration with conservation authorities over 24 months. Human, animal, and wildlife samples were examined for trypanosomes, Toxoplasma gondii, Cryptosporidium, Echinococcus species, Taenia species, and filarial parasites using microscopy, ELISA, and PCR-based methods. Trypanosoma brucei was detected by PCR in 4.5 percent of humans, 12.3 percent of cattle, and 18.6 percent of warthogs. Echinococcus granulosus was confirmed in 6.0 percent of humans and 15.3 percent of dogs. Molecular typing identified shared genotypes between human and livestock Cryptosporidium isolates in 7.0 percent of co-sampled household pairs. Network analysis identified domestic dogs and cattle as the most epidemiologically connected zoonotic bridges between wildlife and human populations. The study presents the first multi-pathogen one-health zoonotic parasite network analysis from the Lake Chad Basin and provides an evidence base for integrated surveillance policy. Keywords: one-health, zoonotic parasites, Chad Basin, Echinococcus, Trypanosoma brucei.