Files
Abstract
The immune response to Histomonas meleagridis and dynamics of lateral transmission was investigated in turkeys. The inoculation of birds 2-16 weeks old produced no evidence of age differences in susceptibility. Commingling of uninoculated poults with infected poults in battery cages showed that litter type was not important in transmission, but infection rates were higher on bedding compared with wire floors. Repeated infection and treatment with dimetridazole produced birds resistant to reinfection, shown by reduced liver and cecal lesions. Immune protection was investigated by inoculation of poults with live or dead Histomonas from cultures. Vaccination by subcutaneous or intramuscular routes produced a protective response as shown by a reduction in the number of infected birds and the severity of lesions after commingling with infected birds. An ELISA test was devised to analyze the antibody response. Turkeys produced IgG antibodies in response to infection and after vaccination with killed histomonads.