Serodiagnosis of infection withTrypanosoma evansi in camels in the Sudan

Abstract

Five diagnostic tests for infection with Trypanosoma evansi have been compared in groups of camels experimentally infected or exposed to natural infection in the Sudan. The correlation of positive results obtained by assays of IgM levels, the mercuric chloride test and the formol gel test with the presence of active infection was unsatisfactory, but there was a good correlation between results obtained using IFAT and ELISA and proven infection. Sera from a high proportion of apparently uninfected camels from endemic areas gave positive reactions with all 5 tests, possibly indicating inadequate parasitological diagnosis or persistence of antibody after unsatisfactory chemotherapy. It was concluded that serological tests using trypanosomal antigens to detect antibodies were more sensitive for diagnosis than indirect tests based on raised euglobulin levels. Serodiagnostic tests may therefore have a place in future programmes for surveillance and control of T. evansi infections in camels.

Clinical, Parasitological and Immunological Aspects of Experimental Infection with Trypanosoma evansi in Dogs

“…by Elisa-test. These findings are similar to those described by other workers using both tests in sera of rabbits (Luckins et al 1978) and camels (Luckins et al 1979) where antibodies were revealed within 10 to 15 days after infection. Even though IFAT was precocious in detecting trypanosomal antibodies, the pattern of antibody production measured by Elisa and IFAT was very similar revealing a good agreement between both tests.…”

Evaluation of enzyme immunoassays in the diagnosis of camel (Camelus dromedarius) trypanosomiasis: a preliminary investigation

“…Serological assays may provide a convenient alternative to examination of blood films for identification of infection with T. evansi. Previous surveys for trypanosomiasis in camels have shown that in areas where the disease occurs large numbers of camels show serological evidence of infection (Luckins et al 1979). However, problems in the interpretation of the results of serological assays such as ELISA tests means that it is difficult to determine the infection status of individual animals.…”

“…Thus, in camels and rabbits infected with T. evansi, antibodies appear within 14 days of infection and remain throughout the duration of -the infection. Following treatment and elimination of infection, although there is decline, antibodies persist in the circulation for up to 100 days after treatment (Luckins, Gray & Rae, 1978;Luckins et al 1979). Antigens released by the parasites can be detected in serum as early as 5 days after infection.…”

“…In order to improve diagnostic efficiency, several serological tests have been used to detect T. evansi antibodies in the camel. These include the complement fixation test (Schoening, 1924), indirect fluorescent antibody assays (Luckins et al 1979) and indirect haemagglutination tests (Wilson et al 1983).…”

“…antibodies and antigens in animal sera (Luckins & Mehlitz, 1978;Luckins et al 1979;Rae & Luckins, 1984).…”