Use of Trypanosoma antigen detection ELISA during an epidemiological survey in the Sideradougou area, Burkina Faso

Abstract

Plasmas taken during a parasitological survey on bovine trypanosomosis were tested a posteriori with an antigen detection ELISA test. The objective was to evaluate the value of this test for epidemiological monitoring. The results were compared to those obtained using the usual parasitological technique (buffy coat examination). Of the 297 zebu cattle heads studied, 216 came from four villages in the pastoral zone of Sideradougou. A large eradication programme had led to the disappearance of tsetse in the area. Blood samples were taken during the rainy saison (September 1986), at the beginning (january 1987) and at the end (May 1987) of the dry season. The parasitological diagnosis was carried out in the field and plasmas were stored at -20°C. The serological test was performed in August 1993. The incidence rates of bovine trypanosomosis obtained with antigen detection ELISA were low in the tenter of the zone. These rates decreased proportionally to the distance between the blood sampling area and the limit of the infested area. The results of the parasitological diagnosis were similar except for a village located on the border of the treated zone. The use of antigen detection ELISA confirmed the low incidence of trypanosomosis in the center of the area of Sideradougou following the eradication campaign. It also enables to obtain finer parasitological results pointing out the trypanosome persistence in peripheric zones, more exposed to reinfestations.