A simple classification of different types of trypanosomiasis occurring in four camel herds in selected areas of Kenya.

Abstract

Jugular vein serum and blood samples were taken every 2 to 3 months for 9 to 15 month periods from a total of 508 camels from 4 herds in different areas in Kenya. Mouse inoculation tests and examination of stained samples showed Trypanosoma to be present to a varying degree in all 4 herds; the species responsible were mostly T. evansi and T. brucei but T. congolense was isolated from 4 camels (2 herds). The camels were divided into 5 types according to mortality, presence of circulating trypanosomes and antibodies and presence of anaemia and emaciation. Herd profiles are constructed according to the percentage of the different types present during the observation periods. The point prevalence rate for IHA antibody was high for all herds during most of the study period, showing trypanosomiasis to be endemic in the herds. There was no difference in the incidence rate (IR) of humoral antibody between the 3 age groups studied. The IR for circulating trypanosomes was significantly lower in calves (≤1 year) than in immatures (1-4 years) or adults (more than 4 years) and that of immatures was significantly higher than of adults. The high antibody IR in calves may be partly maternal antibody. Death due to Trypanosoma was confirmed in 4 animals from 2 herds.ADDITIONAL ABSTRACT:Jugular vein serum and blood samples were taken every 2 to 3 months for 9 to 15 month periods from a total of 508 camels from 4 areas in Kenya. Mouse inoculation tests and examination of stained samples showed Trypanosoma to be present to a varying degree in all 4 herds; the species responsible were mostly T. evansi and T. brucei but T. congolense was isolated from 4 camels (2 herds). The camels were divided into 5 types according to mortality, presence of circulating trypanosomes and antibodies and presence of anaemia and emaciation. Herd profiles are constructed according to the percentage of the different types present during the observation periods. The point prevalence rate for IHA antibody was high for all herds during most of the study period, showing trypanosomiasis to be endemic in the herds. There was no difference in the incidence rate (IR) of humoral antibody between the 3 age groups studied. The IR for circulating trypanosomes was significantly lower in calves (≤1 year) than in immatures (1-4 years) or adults ( more than 4 years) and that of immatures was significantly higher than of adults. The high antibody IR in calves may be partly maternal antibody. Death due to Trypanosoma was confirmed in 4 animals from 2 herds.