Field and experimental symptomless infections support wandering donkeys as healthy carriers of Trypanosoma vivax in the Brazilian Semiarid, a region of outbreaks of high mortality in cattle and sheep.

摘要: The Brazilian Semiarid is the home of largest herd donkeys in South America and outbreaks Trypanosoma vivax infection high mortality dairy cattle sheep. For a comprehensive understanding underlying mechanisms these epidemiological role donkeys, we surveyed for T. wandering follow experimental sheep with highly virulent isolate from Semiarid. Blood samples 180 randomly selected region were employed PCV parasitemia assessments tested using vivax-specific TviCATL-PCR assay. PCR-amplifed Cathepsin L (CATL) sequences genotyping phylogenetic analysis. Four experimentally infected obtained during an outbreak Semiarid; control group consisted two non-inoculated donkeys. We detected 30 (16.6 %) TviCATL-PCR. prevalence was higher dry (15.5 %) than wet season (1.1 %) more females (23.1 %) males (8.9 %) infected. All PCR-positive lacked patent showed normal values body condition score (BCS) packed cell volume (PCV). To evaluate probable tolerance to vivax, inoculated five (TviBrRp) became PCR-positive, but their always subpatent. A goat TviBrRp increasing concurrently fever, declining PCV, tachycardia, mucous membrane pallor, enlarged lymph nodes anorexia. None signs observed However, shared identical or similar genotypes (identified by sequences) isolates acute disease This first report Brazil and, our knowledge, vivax. symptomless field infections corroborated that are tolerant other livestock species as shown African countries. Therefore, farmers, veterinaries programmes should be aware healthy carrier possible source susceptible