Heterakis vesicularis Frolich 1791: A vector of an infectious disease.

Abstract

Several parasites, a flagellate of the genus Giardia and also microsporidia have been reported in intestinal round worms, but up to the present time the latter have not been shown to be concerned in the transmission of disease.Blackhead, an infectious disease of turkeys and other poultry, is caused by a flagellate, Histomonas meleagridis. It is transmitted experimentally and to some extent in nature by the direct ingestion of material contaminated with freshly passed discharges containing the protozoon. It appears, however, to be much more frequently transmitted indirectly by some phase distributed on the soil, evidently in association with the eggs of the caecal worm, H. vesicularis.The presence of the protozoon in the egg of Heterakis is indicated by experimental evidence of various sorts.1. Heterakis eggs kept in 1.5 per cent nitric acid until embryonated produce blackhead when fed to young birds isolated from all other sources of infection, although this treatment renders the material bacteriologicall...