title: Detection of Vaccinia Virus in Milk: Evidence of a Systemic and Persistent Infection in Experimentally Infected Cows.
abstract: Bovine vaccinia (BV) is a zoonosis caused by Vaccinia virus (VACV), which affects lactating cows and milkers. VACV DNA and infectious particles have been detected in milk of naturally infected cows. However, the period and pattern of VACV shedding in milk is unknown, as is whether the presence of VACV in milk is due to a localized or a systemic infection. To address those questions, eight lactating cows were inoculated with VACV in previously scarified teats. The experiment was divided in two phases. In Phase 1, milk samples were collected daily for 33 days, and in Phase 2, four animals from the first phase were immunosuppressed. In both phases, milk was collected with a sterile catheter on even days and by hand milking on odd days. All animals showed typical BV lesions in the inoculated teats. All milk samples were subjected to nested polymerase chain reaction (PCR) and real-time quantitative PCR to detect VACV DNA. PCR-positive samples were subjected to virus isolation. VACV DNA was intermittently detected in milk in both phases and infectious viral particles could be detected only in phase 2, on the 69th, 73rd, 74th, 77th, 79th, and 81st days postinfection. Despite the possibility of propagation of VACV through milk, it is known that milk continues to be drawn and marketed normally during outbreaks of the disease. The detection of both VACV DNA and infectious particles in milk samples draws attention to the potential public health risk associated with the consumption of milk from BV outbreaks. Detection of VACV in the milk from noninfected teats demonstrated that VACV shedding in milk might be related to a systemic infection. Moreover, it was shown that VACV DNA and viral infectious particles could be detected in milk even after healing of the lesions, demonstrating that VACV may cause a persistent infection in cattle.
authors.affiliation: 1 Laboratório de Pesquisa em Virologia Animal, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .
authors.forename: Tércia Moreira Ludolfo
authors.initials: TM
authors.lastname: de Oliveira
authors.affiliation: 1 Laboratório de Pesquisa em Virologia Animal, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .
authors.forename: Maria Isabel Maldonado Coelho
authors.initials: MI
authors.lastname: Guedes
authors.affiliation: 1 Laboratório de Pesquisa em Virologia Animal, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .
authors.forename: Izabelle Silva
authors.initials: IS
authors.lastname: Rehfeld
authors.affiliation: 1 Laboratório de Pesquisa em Virologia Animal, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .
authors.forename: Ana Carolina Diniz
authors.initials: AC
authors.lastname: Matos
authors.affiliation: 1 Laboratório de Pesquisa em Virologia Animal, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .|2 LANAGRO-Laboratório Nacional Agropecuário de Minas Gerais Ministério da Agricultura, Pecuária e Abastecimento (MAPA) , Pedro Leopoldo, Brazil .
authors.forename: Anselmo Vasconcelos
authors.initials: AV
authors.lastname: Rivetti
authors.affiliation: 3 Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .
authors.forename: Pedro Augusto
authors.initials: PA
authors.lastname: Alves
authors.affiliation: 1 Laboratório de Pesquisa em Virologia Animal, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .
authors.forename: Grazielle Cossenzo Florentino
authors.initials: GC
authors.lastname: Galinari
authors.affiliation: 4 Laboratório de Microbiologia de Leite, Departamento de Tecnologia e Inspeção de Produtos de Origem Animal, Escola de Veterinária, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .
authors.forename: Mônica Maria Oliveira Pinho
authors.initials: MM
authors.lastname: Cerqueira
authors.affiliation: 3 Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .
authors.forename: Jônatas Santos
authors.initials: JS
authors.lastname: Abrahão
authors.affiliation: 1 Laboratório de Pesquisa em Virologia Animal, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais , Belo Horizonte, Brazil .
authors.forename: Zélia Inês Portela
authors.initials: ZI
authors.lastname: Lobato
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000378:metabolism* / Q000821:virology; D004279:DNA, Viral / Q000032:analysis*; D004196:Disease Outbreaks / Q000662:veterinary; D005260:Female; D007774:Lactation / Q000378:metabolism; D008892:Milk / Q000821:virology*; D016133:Polymerase Chain Reaction; D014615:Vaccinia / Q000378:metabolism* / Q000662:veterinary / Q000821:virology; D014616:Vaccinia virus / Q000235:genetics / Q000302:isolation & purification*; D014771:Virion / Q000302:isolation & purification; D017201:Virus Shedding
chemical_list: D004279:DNA, Viral