Acquired immunity to Trichuris suis infection in pigs.
Strong resistance to reinfection developed in pigs as a result of trickle inoculations with Trichuris suis (250 infective eggs twice weekly for 4 weeks). At challenge (4000 eggs) 8 weeks after the last trickle inoculation, we observed a 96% reduction in the mean number of established challenge worms in immunized (TRI/CHA) compared with non-immunized controls (CON/CHA) (74 v. 1753; P = 0.004). Moreover, the total faecal egg excretion was significantly lower in immunized pigs compared with controls (P = 0.0003). The trickle inoculations depressed pig weight gains over the 8-week course of immunization (P = 0.042). It was observed that a small number of pigs developed a weaker level of resistance, reflecting the importance of genetic determinants. The relevance of these data to the population biology of porcine and human whipworm infections is discussed.
Pedersen
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Danish Centre for Experimental Parasitology, The Royal Veterinary and Agricultural University, Frederiksberg, Copenhagen. skp@kvl.dk
Saeed
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D000818:Animals; D002432:Cecum / Q000469:parasitology; D003106:Colon / Q000469:parasitology; D005243:Feces / Q000469:parasitology; D005260:Female; D007114:Immunization / Q000662:veterinary*; D008297:Male; D010270:Parasite Egg Count / Q000662:veterinary; D010550:Personal Space; D011897:Random Allocation; D013047:Specific Pathogen-Free Organisms; D018709:Statistics, Nonparametric; D013552:Swine; D013553:Swine Diseases / Q000276:immunology* / Q000469:parasitology; D014257:Trichuriasis / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D014258:Trichuris / Q000276:immunology*