RESUMO
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.
Assuntos
Equidae/parasitologia , Doenças dos Cavalos/epidemiologia , Trypanosoma/isolamento & purificação , Tripanossomíase/veterinária , Animais , DNA de Protozoário/análise , Gâmbia/epidemiologia , Doenças dos Cavalos/sangue , Doenças dos Cavalos/diagnóstico , Cavalos , Incidência , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Prevalência , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Trypanosoma/genética , Tripanossomíase/diagnóstico , Tripanossomíase/epidemiologiaRESUMO
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.
Assuntos
DNA de Protozoário/sangue , Doenças das Cabras/diagnóstico , Reação em Cadeia da Polimerase/veterinária , Trypanosoma/genética , Tripanossomíase Africana/veterinária , Animais , Primers do DNA/química , Eletroforese em Gel de Ágar/veterinária , Gâmbia/epidemiologia , Doenças das Cabras/epidemiologia , Cabras , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Trypanosoma/isolamento & purificação , Tripanossomíase Africana/diagnóstico , Tripanossomíase Africana/epidemiologiaRESUMO
Six goats were experimentally infected with a stock of Trypanosoma vivax. Parasitaemia was weekly monitored by buffy coat and wet blood film examination during a period of 15 weeks and another 3 weeks following drug-treatment. Dried blood samples were tested by the polymerase chain reaction (PCR), using an extraction method with Chelex 100 (BioRad). PCR proved consistently more sensitive than the parasitological techniques.
