The course of primary infection with Necator americanus in syngeneic mice.

WELLS C. and BEHNKE .I. M. 1988. The course of primary infection with Necutoramericanus in syngeneic mice. Internationul Journul for Purasitology 18: 41-5 1. A panel of syngeneic mouse strains was compared for susceptibility to infection with a hamster adapted strain of N. americunus. Lung worm burdens were compared 4-5 days after percutaneous exposure to 190-375 larvae. SJL and DBA/l were most susceptible. Balb/c, DBA/Z and CBAstrains showed intermediate worm burdens and SWR, C,,BL,,,, NIH and C3H/HR mice were the most resistant. NIH and Balb/c mice consistently showed significant differences in lung worm establishment and were selected for closer examination. The recovery of larvae from the skin on day 2 and the subsequent rate of loss from this site were similar in both strains. However. Balb/c mice developed significantly higher lung worm burden than NIH and the rate of loss from the lung was more rapid. L, larvae were first recovered from the small intestines of Balb/c mice on day 7, numbers reaching a peak on day Y when the mean intestinal recovery corresponded to 10% of the peak lung burden. Intestinal stages were not found in NIH mice and no larvae were found in other tissue sites of either strain. The relevance of N. americanus in mice as a model for the study of host-parasite relationships of the invasive and migratory stages of hookworms is discussed. INDEX