Development and transmission of Oswaldocruzia pipiens Walton, 1929 (Nematoda: Trichostrongylidae) in amphibians

Abstract

Development of Oswaldocruzia pipiens was similar to that of other trichostrongyles which have been studied. First-stage larvae have a valved, rhabditiform oesophagus. Infective larvae are ensheathed and have a strongyliform oesophagus. Development to the infective stage occurred in faeces and transmission was by skin penetration. In frogs, early development occurred on the mucosa of the stomach: worms then migrated to the anterior portion of the intestine. The prepatent period was 14–18 days at 14–18 °C. Patent infections developed in experimentally infected tadpoles of Rana sylvatica. However, there was no evidence of natural infections in tadpoles. There were no significant fluctuations of prevalence and intensity between April and October, 1976 and 1977, in transformed R. sylvatica from a single marsh near Guelph, Ontario. Transmission apparently took place during spring and throughout the summer. Young frogs acquired infections rapidly.