Trichuris

Whipworm (Trichuris trichiurd) adult females are 5 cm long. These worms thread their entire body into the epithelium of the colon, where they feed on tissue juice and small amounts of blood. Infections of several hundred worms may cause irritation and inflammation of the mucosa, with abdominal pain, diarrhea, and gas. Eggs are discharged and passed into the feces. Infections result from the swallowing of eggs that are obtained directly from contaminated soil. Untreated adult worms Hve for years. 

There is good evidence, for a number of helminth species, that different parasite lines vary in their infection characteristics in hosts, much of which is reviewed by Read and Viney (1996). For example, different isolates of Trichinella spiralis vary in the kinetics of their primary infection in the same mouse strain. Crucially, these differences are removed when mice are immunosuppressed (Bolas-Fernandez and Wakelin, 1989). Analogous observations have been made for Trichuris muris in mice. Different isolates differed in the kinetics of infection and expulsion. However, in immunosuppressed mice, all isolates had similar fecundity (Bellaby et al., 1995). Combined, these observations show immune-dependent variation between parasite lines in their infection kinetics. 

Bellaby, T., Robinson, K., Wakelin, D. and Behnke, J.M. (1995) Isolates of Trichuris muris vary in their ability to elicit protective immune responses to infection in mice. Parasitology 111, 353-357. 

Fetterer, R.H. and Hill, D.E. (1993) The occurrence of phenol oxidase activity in female Trichuris suis. Journal of Parasitology 79, 155—159. 

Table 17.1. Mean worm burdens in IL-13 knockout (KO), IL-4 KO and wild-type mice at day 35 post-Trichuris muris infection.

Artis, D., Potten, C.S., Else, K.J., Finkelman, F.D. and Grencis, R.K. (1999b) Trichuris muris. host intestinal epithelial cell hyperproliferation during chronic infection is regulated by interferon-y. Experimental Parasitology 92, 144-153. 

Betts, C.J. and Else, K.J. (1999) Mast cells, eosinophils, and antibody-mediated-cellular-cytotoxicity are not critical in resistance to Trichuris muris. Parasite Immunology 21, 45-52. 

Else, K.J. and Wakelin, D. (1988) The effects of H-2 and non H-2 genes on the expulsion of the nematode Trichuris muris from inbred and congenic mice. Parasitology 96, 543-550. 

Else, KJ. and Wakelin, D. (1989) Genetic variation in the humoral immune response of mice to the nematode Trichuris muris. Parasite Immunology 11, 77-90. 

Else, KJ., Wakelin, D., Wassom, D.L. and Hauda, KM. (1990a) The influence of genes mapping within the major histocompatibility complex on resistance to Trichuris muris infections in mice. Parasitology 101, 61-67. 

Faulkner H.F., Renauld, J.C., Van Snick, J. and Grencis, R.K (1998) Interleukin-9 enhances resistance to the intestinal nematode Trichuris muris. Infection and Immunity 66, 3832-3840. 

Grencis, R.K. and Cooper, E.S. (1996) Enterobius, Trichuris, Capillaria, and hookworm including Ancylostoma caninum. Gastroenterology Clinics of North America 25, 579-597. 

Ito, Y. (1991) The absence of resistance in congenitally athymic nude mice toward infection with the intestinal nematode, Trichuris muiis. resistance restored by lymphoid cell transfer. InternationalJournal of Parasitology 21, 65-69. 

Koyama, K., Tamanchi, H. and Ito, Y. (1995) The role of CD4+ and CD8+ T cells in protective immunity to the murine parasite Trichuris muris. Parasite Immunology 17, 161-165. 

Koyama, K., Tamauchi, H., Tomita, M., Kitajima, T. and Ito, Y. (1999) B cell activation in the mesenteric lymph nodes of resistant BALB/c mice infected with the murine nematode parasite Trichuris muris. Parasitology Research 85, 194—199. 

Needham, C.S., Lillywhite, J.E., Didier, J.M., Bianco, A.E. and Bundy, D.A.P. (1994) Temporal changes in Trichuris trichiura infection and serum isotype responses in children. Parasitology 109,197-200. 

Soltys, J., Goyal, P.K. and Wakelin, D. (1999) Cellular immune responses in mice infected with the intestinal nematode Trichuris muris. Experimental Parasitology 92, 40-47. 

Else, KJ., Hultner, L. and Grencis, R.K. (1992) Cellular immune responses to the murine nematode parasite Trichuris muris. II. Differential induction of TH-cell subsets in resistant versus susceptible mice. Immunology 75, 232-237. 

Hall, GA., Rutter, J.M. and Beer, R.J. (1976) A comparative study of the histopathology of the large intestine of conventionally reared, specific pathogen free and gnotobiotic pigs infected with Trichuris suis. Journal of Comparative Pathology 86, 285—292. 

MacDonald, T.T., Choy, M.Y., Spencer, J., Richman, P.I., Diss, T., Hanchard, B., Venugopal, S., Bundy, D.A. and Cooper, E.S. (1991) Histopathology and immunohistochemistry of the caecum in children with the Trichuris dysentery syndrome. Journal of Clinical Pathology 44, 194-199. 

Larsen, M. N. and Roepstorff, A. (1999). Seasonal Variation in Development and Survival of Ascaris suum and Trichuris suis Eggs on Pastures. 17th International Conference of the World Association for the Advancement of Veterinary Parasitology, Copenhagen. 

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