DIAGNOSIS OF CHRONIC TRYPANOSOMA EVANSI INFECTION AMONG SEROLOGICALLY POSITIVE CAMELS USING A LATEX AGGLUTINATION TEST FOR THE DETECTION OF CIRCULATING TRYPANOSOMAL ANTIGENS

A total of 10⁴ imported Sudanese camels were tested for Trypanosoma evansi infection aiming to determine the prevalence of camels with chronic latent disease that may act as an exotic source of infection. The research employed direct blood smear examination, micro-haematocrit centrifugation technique (MHCT),  card agglutination test (CATT/T. evansi) for antibody detection and latex agglutination test for detection of circulating trypanosomal antigens. Blood smear examination and MHCT have detected patent parasitemia in 5 camels (4.8%). Thirty (28.84%) serologically positive camels had also circulating trypanosomal antigens. Eight (7.69%) serological reactors were negative for antigens, while 12 (11.5%) camels with detectable levels of circulating antigens, tested negative for antibodies. A total of 42 (40.30%) camels were positive for circulating antigens, an indication of current infection. It was evident that the existence of circulating trypanosomal antigens dose not correlate with the presence of specific antibodies. Detection of circulating T-.evansi antigens using latex agglutination test was found to be a more sensitive and reliable means of practical diagnosis of carrier camels suffering chronic latent infection. The epidemiological importance of results is discussed.