de Oliveira Tércia Moreira Ludolfo, Guedes Maria Isabel Maldonado Coelho, Rehfeld Izabelle Silva, Matos Ana Carolina Diniz, Rivetti Anselmo Vasconcelos, Alves Pedro Augusto, Galinari Grazielle Cossenzo Florentino, Cerqueira Mônica Maria Oliveira Pinho, Abrahão Jônatas Santos, Lobato Zélia Inês Portela
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 .
Foodborne Pathog Dis. 2015 Nov;12(11):898-903. doi: 10.1089/fpd.2015.1974.
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.
牛痘（BV）是由痘苗病毒（VACV）引起的一种人畜共患病，可感染泌乳奶牛和挤奶工。在自然感染奶牛的乳汁中已检测到VACV DNA和感染性颗粒。然而，VACV在乳汁中的排出时期和模式尚不清楚，乳汁中VACV的存在是由于局部感染还是全身感染也不清楚。为了解决这些问题，对8头泌乳奶牛先前划破的乳头接种VACV。实验分为两个阶段。在第1阶段，连续33天每天采集乳汁样本，在第2阶段，对第1阶段的4只动物进行免疫抑制。在两个阶段中，偶数日用无菌导管采集乳汁，奇数日用手工挤奶。所有动物在接种的乳头处均出现典型的BV病变。所有乳汁样本均进行巢式聚合酶链反应（PCR）和实时定量PCR以检测VACV DNA。PCR阳性样本进行病毒分离。在两个阶段的乳汁中均间歇性检测到VACV DNA，仅在感染后第69、73、74、77、79和81天的第2阶段检测到感染性病毒颗粒。尽管VACV有可能通过乳汁传播，但已知在疾病暴发期间牛奶仍正常抽取和销售。乳汁样本中VACV DNA和感染性颗粒的检测引起了人们对与BV暴发期间牛奶消费相关的潜在公共卫生风险的关注。在未感染乳头的乳汁中检测到VACV表明乳汁中VACV的排出可能与全身感染有关。此外，还表明即使病变愈合后，乳汁中仍可检测到VACV DNA和病毒感染性颗粒，这表明VACV可能在牛中引起持续性感染。
