A comprehensive review of Onchocercidae nematodes (Nematoda; Filarioidea) infecting wild ruminant ungulates of North and Central America

The family Onchocercidae, or filarioid nematodes, comprises common vector-borne parasitic worms that can infect, among other vertebrates, wild North American ruminant ungulates. Infection is a product of the available hosts and vectors distributed in viable ecosystems that permeate throughout the North America (i.e., Canada, United States, and Mexico) and Central America (i.e., Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama). The formation of these host-parasite assemblages can produce serious to no apparent clinical signs for the infected host animal depending on a multitude of factors. Overall, the scope of our knowledge regarding filarioid nematode infection of North American wild ruminant ungulates remains spotty and neglected throughout the scientific literature. However, reviewing these details provides a foundation for important biological, historical, ecological, and one health relevant questions. Analysis of the current scientific literature reveals that, at this time, nine out of fourteen wild North American ruminant ungulates can be infected with at least one species of filarioid worm. This includes four genera of known Onchocercidae species circulating within the North and Central American ecosystems: Elaeophora, Onchocerca, Rumenfilaria, and Setaria.