Geology topics
J.O. Knisley
Publications and source records attributed to J.O. Knisley.
Challenge infection as a means of determining the rate of disease resistant Trichomonas gallinae-free birds in a population
Trichomonas gallinae -free pigeons and mourning doves were infected with the Jones' Barn strain of T. gallinae to determine the rate of disease resistant T. gallinae -free birds in each population. Although all birds became infected 88% of the pigeons were resistant to trichomoniasis while 82% of the mourning doves were resistant. It was concluded that these birds had been previously infected and spontaneously lost their trichomonad fauna while retaining their resistance to fatal infection.
Incidence of malaria in a wintering population of canvasbacks (Aythya valisineria) on Chesapeake Bay
Canvasback ducks wintering on Chesapeake Bay had a 6% incidence of Leucocytozoon sirnondi and 2% incidence of Haemoproteus. Sub-inoculation of whole blood into Pekin ducklings produced a Plasmodium infection rate of 31%. Females were more frequently infected (12/22) than males (15/68). The parasite was identified as P. circumflexum.
Subinoculation as a technique in the diagnosis of avian plasmodium
In two successive years, 1964 and 1965, blood subinoculated from wild Canada geese, negative for Plasmodium by examination of peripheral blood smears, into 5-day-old domestic geese produced 60 % infection in the recipients. Prepatent and patent periods, as well as intensity of parasitemia showed much variation. Intramuscular inoculation produced the same prevalence as the intravenous route, but longer prepatent periods and less intensity of parasitemia.