First description of Theiler's disease-associated virus infection and epidemiological investigation of equine pegivirus and equine hepacivirus coinfection in Brazil.

Recent advances in the study of equine pegivirus (EPgV), Theiler's disease-associated virus (TDAV) and equine hepacivirus (EqHV) highlight their importance to veterinary and human health. To gain some insight into virus distribution, possible risk factors, presence of liver damage and genetic variability of these viruses in Brazil, we performed a cross-sectional study of EPgV and TDAV infections using a simultaneous detection assay, and assessed EqHV coinfection in different horse cohorts. Of the 500 serum samples screened, TDAV, EPgV and EPgV-EqHV were present in 1.6%, 14.2% and 18.3%, respectively. EPgV-positive horses were present in four Brazilian states: Espírito Santo, Mato Grosso do Sul, Minas Gerais and Rio de Janeiro. Serum biochemical alterations were present in 40.4% of EPgV-infected horses, two of them presenting current liver injury. Chance of infection was 2.7 times higher in horses ≤5 years old (p = 0.0008) and 4.9 times higher in horses raised under intensive production systems (p = 0.0009). EPgV-EqHV coinfection was 75% less likely in horses older than 5 years comparatively to those with ≤5 years old (p = 0.047). TDAV-positive animals were detected in different horse categories without biochemical alteration. Nucleotide sequences were highly conserved among isolates from this study and previous field and commercial product isolates (≥88% identity). Tree topology revealed the formation of two clades (pp = 1) for both EPgV and TDAV NS3 partial sequences. In conclusion, the widespread presence of EPgV-RNA suggests an enzootic infection with subclinical viremia in Brazil. Horse management can influence virus spread. This first report of TDAV-infected horses outside the USA reveals the existence of subclinical viremic horses in distant geographical regions. EPgV and TDAV have similar circulating isolates worldwide. These findings contribute to global efforts to understand the epidemiology and pathogenesis of these equine viruses.

First report of equine Pegivirus in South America, Brazil.

The human Pegivirus (HPgV, also known as GBV-C virus or hepatitis G virus) is a lymphotropic RNA-virus phylogenetically related to the Hepatitis C virus, which infects approximately 5% of the world's human population. Recently, two novel, presumably hepatotropic, pegiviruses, designated as equine Pegivirus (EPgV) and Theiler's Disease Associated Virus (TDAV), were discovered in horses with clinical and laboratory evidence of hepatic disease. To verify the occurrence of pegiviruses infection in horses from Pará State, northern Brazil, serum samples from 114 horses located in four cities (Acará, Belém, Dom Eliseu and Ananindeua) were submitted for the molecular analysis of EPgV by nested RT-PCR. The results of nucleotide sequencing and phylogenetic analysis of EPgV NS3 and NS5B genomic regions confirmed one positive sample among 114 tested samples (1/114; 0.8%). No evidence of TDAV infection was found, but despite the low prevalence and unknown clinical significance among the studied population, these results represent the first molecular detection of EPgV in horses in South America.

Prevalência e fatores associados à infecção pelo vírus da diarréia viralbovina na região Sul do Rio Grande do Sul / Prevalence and factors associated with bovine viral diarrhea virus infection in South of Rio Grande do Sul

O presente estudo teve como objetivo estimar a prevalência e determinar os principais fatores associadosà infecção pelo vírus da diarréia viral bovina (BVDV) no rebanho bovino dos municípios de Santa Vitóriado Palmar e Chuí, na região sul do estado do Rio Grande do Sul. Amostras de soro foram submetidas àprova de soroneutralização e, em cada propriedade avaliada, aplicou-se um questionário epidemiológicopara investigar fatores que poderiam estar associados à infecção. As amostras de soro foram coletadasem 85 propriedades, cujos animais apresentavam ou não sinais clínicos de infecção pelo BVDV. Das1.734 amostras de soro analisadas, 1.150 (66,32%) foram positivas com a detecção de bovinossorologicamente positivos em 70 (82,35%) propriedades. Dentre os fatores avaliados, exploração mista,criação extensiva, realização de ordenha mecânica, uso de inseminação artificial ou de inseminaçãoartificial associada à monta natural, uso de piquete de parição e ausência de assistência veterinária,apresentaram significância estatística (P<0,05) associada à soropositividade. Os resultados obtidosdemonstram a expressiva disseminação do BVDV no rebanho bovino dessa região do Rio Grande do Sul.

This study was performed in order to estimate the prevalence of bovine viral diarrhea virus (BVDV), andto determine the main factors related to the prevalence of the infection in cattle of Santa Vitória do Palmarand Chuí counties, in Rio Grande do Sul State. Sera were submitted to the serum neutralization test andan epidemiological questionnaire was filled out in each herd to investigate variables that could beassociated with this infection. The sera samples were collected in 85 farms, with or without clinical signsof BVDV infection. From 1.734 serum samples examined, 1.150 (66.32%) in 70 (82.35%) herds were positive.Variables that were identified as risk factors to seropositivity were mixed (dairy and beef) herds, extensive production, use of mechanical milking, use of artificial insemination or artificial insemination associated with natural service, use of the maternity unit at calving and absence of veterinarian assistance (P<0.05).The results demonstrate the expressive dissemination of the BVDV in cattle of this region in Rio Grande do Sul