A infecção pelo vírus da diarréia viral bovina (BVDV) no Brasil: histórico, situação atual e perspectivas

Abstract

A infecção pelo vírus da Diarréia V A infecção pelo vírus da Diarréia V A infecção pelo vírus da Diarréia V A infecção pelo vírus da Diarréia V A infecção pelo vírus da Diarréia Viral Bovina (BVDV) In addition to variable levels of positive serology in beef and dairy cattle, BVDV antibodies have been occasionally detected in swine, wild boars, goats, cervids and water buffaloes. BVDV infection has been diagnosed in aborted fetuses, buffy coats of persistently infected (PI) animals, clinical specimens from animals suffering from different clinical syndromes, semen of bulls of artificial insemination (AI) centers, in healthy fetuses and in commercial fetal bovine serum and/or cultured cells. About 50 isolates have been genetically and/or antigenically characterized up to date, whilst roughly an equivalent number of isolates awaits characterization. Most of the characterized isolates belong to BVDV-1 genotype, non-cytopathic (NCP) biotype, yet some BVDV-2 (and some CP BVDV) have been identified as well. Brazilian BVDV isolates display a high antigenic variability and are markedly different from North American vaccine strains. A few inactivated, polyvalent vaccines are currently licensed in the country, yet vaccination is still incipient in many regions: only about 2.5 million doses were marketed in 2003. The low serological cross-reactivity between vaccine strains and field isolates has recently stimulated national industries to develop vaccines containing Brazilian BVDV-1 and BVDV-2 strains. The overall knowledge about BVDV infection in Brazil has grown considerably in the last years, due to an increasing number of laboratories performing diagnosis and research. Studies on the pathogenesis, serological and molecular epidemiology and production of reagents for diagnosis have contributed decisively for the recent growing knowledge on BVDV infections in the country.

Genetic characterization of Brazilian bovine viral diarrhea virus isolates by partial nucleotide sequencing of the 5'-UTR region

“…Twelve BVDV field strains isolated in tissue culture (Flores et al 2005) and seven BVDV field isolates directly detected by reverse transcription followed by PCR (RT-PCR) in clinical samples (Cortez et al 2005b) were submitted to partial sequencing of 5'UTR region for genotyping and subgenotyping. RNA extraction was performed using TRIzol reagent (Invitrogen).…”

Comparação dos testes de virusneutralização contra os genótipos 1 e 2 do vírus da diarreia viral bovina (BVDV-1 e BVDV-2) em bovinos de rebanhos naturalmente infectados

“…especificamente pelo BVDV-1 ou pelo BVDV-2, uma vez que os dois genótipos do BVDV já foram identificados no Brasil (BOTTON et al, 1998;FLORES et al, 2005;CORTEZ et al, 2006). Tendo em vista a diversidade antigênica do BVDV, em especial a existência de dois grupos antigênicos distintos, alguns pesquisadores enfatizaram a necessidade da utilização de cepas do BVDV-1 e do BVDV-2 nos testes de VN, pois, para uma mesma amostra de soro sanguíneo, podem ser encontrados diferentes resultados (DUBOVI, 1996;FLORES et al, 2000;CHASE et al, 2003;FULTON et al, 2003;SANDVIK, 2005).…”

Clinical and virological characteristics of calves experimentally infected with a Brazilian isolate of bovine viral diarrhea virus type 1a

“…The bovine viral diarrhea virus (BVDV) is a major pathogen of cattle present both in Brazilian herds and cattle worldwide (FLORES et al, 2005;MOENNIG et al, 2005). BVDV infection leads to production and economic losses due to its enteric, respiratory, reproductive, and hemorrhagic clinical manifestations (FLORES et al, 2005;CORTEZ et al, 2006;BIANCHI et al, 2011).…”

“…BVDV infection leads to production and economic losses due to its enteric, respiratory, reproductive, and hemorrhagic clinical manifestations (FLORES et al, 2005;CORTEZ et al, 2006;BIANCHI et al, 2011). It can induce immunosuppression and allows the establishment of secondary infections in the respiratory and enteric systems (POTGIETER, 1995;RIDPATH, 2010).…”

“…In Brazil, there are eight commercial vaccines for BVDV and all of them use inactivated strains of BVDV-1 and/ or BVDV-2. However, BVDV vaccination protects only a relatively small portion of the herd, and in many cases, it is not given systematically (FLORES et al, 2005;ANZILIERO et al, 2015). Therefore, the present study aimed to evaluate the pathogenicity of the Brazilian BVDV 241.10 isolate, classified as BVDV-1a, in calves.…”