Ribeiroia - Geographic Distribution

Geographic Distribution

Ribeiroia ondatrae is widely distributed across the USA, including records from 22 species in 37 states (Johnson and McKenzie 2008). Most records of Ribeiroia-associated malformations have been reported from California, Oregon, Washington, Montana, Minnesota, Wisconsin, New Jersey and Pennsylvania. Less is known about the distribution of Ribeiroia in Canada and Central America. In amphibians, both the abundance of the parasite and the number of observations appear to correlate positively with major bird migratory flyways, with concentrations along the Pacific, Mississippi, and Atlantic flyways (Johnson et al. 2010). This observation suggests definitive (bird) host activity is an important determinant of parasite distribution at the continental scale, but this hypothesis has yet to be rigorously tested. Ribeiroia ondatrae is most often recovered from amphibians in lentic habitats, such as ponds, lakes, and wetlands, which support planorbid snails. Other species of Ribeiroia occur in the Caribbean and South America (R. marini and R. marini guadeloupensis) and in Africa (R. congolensis). However, whether these species infect amphibians or cause limb malformations has not been explored.