PREVALENCIA DE Trypanosoma vivax EN BOVINOS DE LA PROVINCIA DE CORONEL PORTILLO, UCAYALI

Abstract

The objective of the study was to determine the prevalence of Trypanosoma sp. in healthy cattle that are reared in four districts (Callería, Campo Verde, Masisea and Yarina) of the Coronel Portillo Province, Ucayali, using the Woo and the buffy coat stained with Giemsa techniques. The latter was also used to determine the species of trypanosome involved. A total of 289 blood samples were collected in May-July, 2000 from crossbred Zebu cattle. Animals were 8 months till 16 years of age, and managed under an extensive rearing system. The morphometric identification showed that the prevalent species was Trypanosoma vivax. The prevalence of T. vivax was 22.2 ± 4.8% when the Woo technique was used and 5.9 ± 2.7 when the stained smear was used. The Campo Verde district had the higher frequency of positive animals (97%, 62/64). None of the animals showed clinical signs of the disease and only 8 animals had a low hematocrit value. No significant relationship between the presence of the parasite and the low hematocrit was found (p>0.05). It was concluded that the observed prevalence was relatively high, whereas animals have a subclinic or benign infection.Key word: Trypanosoma sp., bovine, Trypanosoma vivax, haemoparasite, Ucayali RESUMENEl objetivo del estudio fue determinar la prevalencia de Trypanosoma sp. en bovinos aparentemente sanos de cuatro distritos (Callería, Campo Verde, Masisea y Yarina) de la provincia de Coronel Portillo, Ucayali, a través de las técnicas de Woo y el frotís delgado de "buffy coat" coloreado con Giemsa; usándose además este último para determinar la especie de tripanosoma involucrado. Se examinó muestras de sangre colectada entre mayo a julio del 2000 de 289 bovinos de cruces cebuinos, con edades entre 8 meses y 16 años, criados en forma extensiva. La identificación morfométrica determinó que la especie prevalente era Trypanosoma vivax. Se obtuvo una prevalencia de T. vivax mediante la técnica de Woo de 22.2 ± 4.8% y mediante la técnica de frotís coloreado de 5.9 ± 2.7%. El distrito de Campoverde presentó la mayor frecuencia de animales positivos (97%, 62/64). Ningún animal mostró signos de la enfermedad y sólo 8 tuvieron hematocrito bajo. No se encontró relación estadística entre la presencia del parásito y el hematocrito bajo (p>0.05). Se concluyó que la prevalencia hallada fue medianamente alta, siendo la infección aparentemente subclínica o benigna.

Detecção de anticorpos IgG anti-Trypanosoma vivax em bovinos através do teste de Imunofluorescência indireta

“…Os resultados aqui foram superiores às taxas de prevalên-cia encontradas em Uganda, Zambia, Guyana, Etiópia e Perú que variaram de 0,05% a 4,8% (Craig 1975, Magona et al 1999, Quispe et al 2003, Sinyangwe 2004, Mulaw 2011) e inferiores àquelas registradas por Toro (1976), Omotainse (1993) Abebe & Jobre (1996), Abenga et al (2004) A variação nas prevalências podem ser reflexo de diferentes formas de manejo, uso de anti-parasitários em algumas regiões além de fatores ligados aos vetores como sua distribuição e competência vetorial (Swai & Kaaya 2012). Além disso, esses estudos foram realizados em diferentes estações do ano o que implica em taxas de infecção por T. vivax variadas pois sabe-se que a densidade dos vetores aumenta na dependência das estações climáticas (Onditi et al 2007).…”

First report of Trypanosoma vivax outbreak in dairy cattle in São Paulo state, Brazil

“…on direct examination, but all 12 samples examined showed trypomastigotes in stained blood smears, although the sensitivity of blood smears for diagnosing infections due to T. vivax is about 10% (QUISPE et al, 2003). The most highly parasitized cow had been raised at a farm in MS, and presented persistent anemia and weight loss.…”

“…In South America, it was probably introduced around 1830 through infected cattle from Africa, and mechanical transmission occurs by means of tabanids such as Stomoxys calcitrans and probably other biting flies (SILVA et al, 1996;VENTURA et al, 2001;JONES;OSÓRIO et al, 2008). Natural infection with T. vivax has been reported in cattle in several countries: Surinam, Venezuela, Colombia, Brazil, Bolivia, Paraguay, Peru and Costa Rica (CLARKSON, 1976;SILVA et al, 1998b;QUISPE et al, 2003;GARCIA et al, 2005;OSÓRIO et al, 2008;OLIVEIRA et al, 2009).…”

“…However, infected cattle may sometimes be asymptomatic (GARDINER, 1989;PAIVA et al, 2000;QUISPE et al, 2003;DÁVILA et al, 2003;BATISTA et al, 2007BATISTA et al, , 2009. If no treatment were made, the estimated financial impact of bovine trypanosomiasis due to T. vivax occurring in the Brazilian Pantanal region (states of Mato Grosso and Mato Grosso do Sul) would be 17% of the total herd value (SEIDL et al, 1997).…”

Diagnostic, Clinical and Epidemiological aspects of dairy cows naturally infected by Trypanosoma vivax in the states of Pernambuco and Alagoas, Brazil

“…In the Americas, the main route of transmission is through the mechanic vectors tabanidae, Stomoxys calcitrans and Haematobia irritans, and through the iatrogenic route (Oliveira et al, 2009;Cadioli et al, 2012). Natural infection by this hemoparasite is already well known and reported in several countries, such as; Venezuela, Paraguay, Colombia, Suriname, Guyana, Bolivia, Peru, and Costa Rica (Quispe et al 2003;Suárez et al, 2009).…”