Studies on host resistance to secondary infections of Raillietina cesticillus Molin, 1858 in the fowl.

TLDR: Worms of secondary infections of Raillietina cesticillus established in 10-week-old birds but failed to grow mature strobilae were taken as an indication of resistance to the cestode as discussed by the authors.

Abstract: Worms of secondary infections of Raillietina cesticillus established in 10-week-old birds but failed to grow mature strobilae. This was taken as an indication of resistance to the cestode. The resistance was inhibited by the immunosuppressant and anti-inflammatory drug dexamethasone, which prevented the local inflammation around attached scolices characteristic of secondary infections of R. cesticillus. Mast cell hyperactivity and eosinophil infiltration in intestinal tissues and immunofluorescent antibodies in sera of infected birds were also demonstrated. Scolices without strobilae from refractory hosts with both primary and secondary infections regrew their strobilae when transplanted into susceptible hosts.