title: Vaccinia virus Transmission through Experimentally Contaminated Milk Using a Murine Model.
abstract: Bovine vaccinia (BV) is a zoonosis caused by Vaccinia virus (VACV), which affects dairy cattle and humans. Previous studies have detected the presence of viable virus particles in bovine milk samples naturally and experimentally contaminated with VACV. However, it is not known whether milk contaminated with VACV could be a route of viral transmission. However, anti-Orthopoxvirus antibodies were detected in humans from BV endemic areas, whom had no contact with affected cows, which suggest that other VACV transmission routes are possible, such as consumption of contaminated milk and dairy products. Therefore, it is important to study the possibility of VACV transmission by contaminated milk. This study aimed to examine VACV transmission, pathogenesis and shedding in mice orally inoculated with experimentally contaminated milk. Thirty mice were orally inoculated with milk containing 107 PFU/ml of VACV, and ten mice were orally inoculated with uncontaminated milk. Clinical examinations were performed for 30 consecutive days, and fecal samples and oral swabs (OSs) were collected every other day. Mice were euthanized on predetermined days, and tissue and blood samples were collected. Nested-PCR, plaque reduction neutralization test (PRNT), viral isolation, histopathology, and immunohistochemistry (IHC) methods were performed on the collected samples. No clinical changes were observed in the animals. Viral DNA was detected in feces, blood, OSs and tissues, at least in one of the times tested. The lungs displayed moderate to severe interstitial lymphohistiocytic infiltrates, and only the heart, tonsils, tongue, and stomach did not show immunostaining at the IHC analysis. Neutralizing antibodies were detected at the 20th and 30th days post infection in 50% of infected mice. The results revealed that VACV contaminated milk could be a route of viral transmission in mice experimentally infected, showing systemic distribution and shedding through feces and oral mucosa, albeit without exhibiting any clinical signs.
authors.affiliation: Laboratório de Pesquisa em Virologia Animal (LPVA), Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Izabelle Silva
authors.initials: IS
authors.lastname: Rehfeld
authors.affiliation: Laboratório de Pesquisa em Virologia Animal (LPVA), Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Maria Isabel Maldonado Coelho
authors.initials: MI
authors.lastname: Guedes
authors.affiliation: Laboratório de Pesquisa em Virologia Animal (LPVA), Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Ana Luiza Soares
authors.initials: AL
authors.lastname: Fraiha
authors.affiliation: Laboratório de Pesquisa em Virologia Animal (LPVA), Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Aristóteles Gomes
authors.initials: AG
authors.lastname: Costa
authors.affiliation: Laboratório de Pesquisa em Virologia Animal (LPVA), Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Ana Carolina Diniz
authors.initials: AC
authors.lastname: Matos
authors.affiliation: Laboratório de Patologia Veterinária, Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Aparecida Tatiane Lino
authors.initials: AT
authors.lastname: Fiúza
authors.affiliation: Laboratório de Pesquisa em Virologia Animal (LPVA), Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Zélia Inês Portela
authors.initials: ZI
authors.lastname: Lobato
mesh_terms: D000818:Animals; D002417:Cattle; D004195:Disease Models, Animal; D005243:Feces / Q000821:virology*; D005260:Female; D051379:Mice; D008892:Milk / Q000821:virology*; D014615:Vaccinia / Q000635:transmission* / Q000821:virology; D014616:Vaccinia virus; D017201:Virus Shedding