The local effect of hypersensitive or inflammatory reactions to nymphal Amblyomma variegatum on simultaneous infections with Dermatophilus congolensis.

Amblyomma variegatum nymphs were applied to sites infected with Dermatophilus congolensis on eight rabbits. Four rabbits were previously sensitized to the feeding of nymphal A. variegatum to produce hypersensitive reactions to the tick feeding; the remaining four rabbits had no previous exposure to nymphal A. variegatum and produced inflammatory reactions to the tick feeding. The resulting dermatophilosis infections were assessed for three weeks and there was a correlation between the position of the inflammatory tick attachment sites and the foci of infection. There was a significant increase in the lesions at sites with inflammatory reactions to the ticks, compared with sites not exposed to tick feeding; these differences appeared to be due to individual variation in the host response and were not sustained throughout the assessment.