The Effect of Concurrent Infection with Nippostrongylus on the Development of Hymenolepis in Mice

Abstract

A few observations have been made but little or no specific work has been done to show what effect the presence of one species of parasite has on the development of a second. Brumpt (1933) noticed that the resistance of one mouse to reinfection with Hymenolepis nana var. fraterna was broken down by a secondary infection with Strongyloides. Apparently there are no reported observations on the mutual effect of two different parasites following simultaneous entry into a host. It was to obtain such information that the present study was undertaken, since the nematode, Nippostrongylus muris, and the cestode, H. nana var. fraterna, were both available in the laboratory at the same time. METHODS Quantitative doses of Hymenolepis eggs isolated from host feces which had been stored 48-72 hours were administered to mice by stomach tube, and 93-hour cysticercoid counts were made after preparing the intestine free from mucus (Larsh, 1942). Infective Nippostrongylus larvae were isolated from 10-20 day old cultures, washed by centrifugation in normal saline, and counts made by a modification of Scott's (1928) dilution count. Known numbers of larvae were injected subcutaneously into mice in the abdominal wall just medial to the flank. EXPERIMENTAL DATA