TRYPANOSOMA-CONGOLENSE INFECTION IN SHEEP - ULTRASTRUCTURAL-CHANGES IN THE SKIN PRIOR TO DEVELOPMENT OF LOCAL SKIN REACTIONS

Events occurring in the skin of sheep prior to development of Trypanos oma congolense-induced local skin reactions (chancres) were studied us ing electron microscopy. Three days after infection, few trypanosomes were present in the dermal collagen. However, these parasites were mor e abundant 5 days after infection, and were also found in dermal lymph atics and in the connective tissue matrix between collagen bundles. Ma st cells in the skin obtained 5 days after infection showed evidence o f degranulation. These events may play a role during the induction pha se of trypanosomal chancres,