ABSTRACT
In a study of the prevalence and incidence of trypanosomosis in horses and donkeys in two regions of the Gambia, surveys were carried out at Niamina east and Bansang south with a high and low to moderate tsetse challenge, respectively. Eleven horses and 67 donkeys were sampled monthly from August 1997 to September 1998. Blood samples were examined for trypanosomes using the buffy-coat (BC) method and polymerase chain reaction (PCR). Three primer sets were used, specific for either Trypanosoma vivax (TVW), Trypanosoma congolense (GOL) or Trypanosoma brucei (ORPHON5J). The BC results showed that the prevalence (August 1997) and the average monthly incidence (September 1997-1998) of trypanosome infections in horses (45.5 and 16%, respectively) were significantly higher than in donkeys (6.2 and 9%, respectively). Using PCR, the number of detected cases was seven times higher than using the BC. T. congolense was the most frequently observed species, followed by T. vivax and T. brucei. This study confirms earlier observations by other authors that donkeys, which are exposed to a similar tsetse challenge as horses, are significantly less infected with trypanosomes than the latter.
Subject(s)
Equidae/parasitology , Horse Diseases/epidemiology , Trypanosoma/isolation & purification , Trypanosomiasis/veterinary , Animals , DNA, Protozoan/analysis , Gambia/epidemiology , Horse Diseases/blood , Horse Diseases/diagnosis , Horses , Incidence , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/veterinary , Prevalence , Sensitivity and Specificity , Seroepidemiologic Studies , Trypanosoma/genetics , Trypanosomiasis/diagnosis , Trypanosomiasis/epidemiologyABSTRACT
The buffy coat of 76 roaming goats from the Bansang and Missira regions in Gambia, was examined for the presence of trypanosomes. From these animals, extractions from dry blood samples on filter paper were subjected to PCR using three different primer sets, ORPHON5J, GOL and TVW, specific for Trypanosoma brucei/Trypanosoma evansi, Trypanosoma congolense and Trypanosoma vivax, respectively. PCR results for T. congolense were 100% concordant with buffy coat examination. Besides the three T. vivax buffy coat-positive samples, another 15 yielded positive with the TVW primers. The ORPHON5J primers yielded no positive results. Analyses with the GOL primers of putatively negative samples, yielded aberrant band patterns whose diagnostic significance still remains to be determined.
