Interaction between Trypanosoma brucei and Haemonchus contortus infection in West African Dwarf Goats

In order to investigate the immunomodulatory influence of concurrent T. brucei and H. contortus infection in West African Dwarf (WAD) goats, 28 infected and 7 uninfected (control) of 8-9 months old male WAD goats were studied. The infected goats were separated into resistant (Class 1) and susceptible (Class 2) Faecal Eggs Count (FEC) phenotypes. They were infected with 3000 infective larvae (L3) of H. contortus and 5 x 106 T. brucei. Another group of these phenotypes received only the H. contortus challenge. The responses were measured by parasitological response through FEC and Worm Burden (WB), and by host immune response through IgG levels. Class 2 animals with or without T. brucei infection exhibited non-significant (P > 0.05) higher FEC compared to those of Class 1. Worm burdens were not significantly different between FEC classes but were different (P=0.038) in relation to T. brucei infection. There was an overall increase in worm burdens of T. brucei infected goats, more pronounced in Class 2 than in Class 1. There was a significant upward drift of antibody levels with time across all groups without significant interactions. However, there was a significant effect of FEC Class (P=0.017) and trypanosome infection (P=0.041) with no significant interaction. Animals in Class 1 had generally higher antibody levels than those in Class 2, irrespective of T. brucei infection. Infection status had a highly significant (P=0.0001) effect on IgG. H. contortus only infected goats had the highest antibody levels and trypanosome infection reduced this response, irrespective of FEC phenotype. There was a highly significant (P=0.001) positive correlation (r = +0.719) between FEC and total worm counts. This work showed that the two response phenotypes identified in earlier immunizing infections were still clearly recognizable following homologous challenge and dual infections. This suggests that under field conditions where repeated H. contortus challenge occurs and trypanosomosis is endemic, the phenotypes could remain unchanged.© 2016 International Formulae Group. All rights reserved.Keywords: Haemoparasite, Gastrointestinal parasite, concurrent infection, immune response, domestic animal

Observations sur les infestations par les strongles, durant la saison sèche, des pâturages à bovins inondés en permanence dans la région de Yom, État du Plateau, Nigeria

Des échantillons d'herbes ont été récoltés dans les environs de 4 mares permanentes (2 très pâturées et 2 peu pâturées), situées dans la région de Vom. Les collectes ont eu lieu tous les 15 jours de novembre 1985 à avril 1986 et de novembre 1986 à avril 1987. Les larves ont été extraites par lavage et sédimentation et les décomptes effectués ont été exprimés en nombre de larves par kg de matière sèche. Parmi les larves de vers présentes dans les coprocultures, on distinguait Haemonchus, Cooperia et Oesophagostomum qui étaient les plus importants. Trichostrongylus, Bunostomum et Strongyloides étaient présents aussi, mais en très petit nombre. Les alentours des mares permanentes très peu pâturés étaient faiblement infestés, alors que ceux très pâturés se révélaient contaminés par de fortes infestations. Les pâturages fortement contaminés deviennent un milieu à risque de la moitié jusqu'à la fin de la saison sèche. Les traitements de routine durant la saison sèche sur les bovins qui ont accès aux pâturages, en particulier dans les zones fortement contaminées, sont dès lors nécessaires