Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
United States Food and Drug Administration, Silver Spring, MD 20993-0002, USA.
Viruses. 2017 Nov 15;9(11):340. doi: 10.3390/v9110340.
The orthopoxviruses (OPV) comprise several emerging viruses with great importance to human and veterinary medicine, including vaccinia virus (VACV), which causes outbreaks of bovine vaccinia (BV) in South America. Historically, VACV is the most comprehensively studied virus, however, its origin and natural hosts remain unknown. VACV was the primary component of the smallpox vaccine, largely used during the smallpox eradication campaign. After smallpox was declared eradicated, the vaccination that conferred immunity to OPV was discontinued, favoring a new contingent of susceptible individuals to OPV. VACV infections occur naturally after direct contact with infected dairy cattle, in recently vaccinated individuals, or through alternative routes of exposure. In Brazil, VACV outbreaks are frequently reported in rural areas, affecting mainly farm animals and humans. Recent studies have shown the role of wildlife in the VACV transmission chain, exploring the role of wild rodents as reservoirs that facilitate VACV spread throughout rural areas. Furthermore, VACV circulation in urban environments and the significance of this with respect to public health, have also been explored. In this review, we discuss the history, epidemiological, ecological and clinical aspects of natural VACV infections in Brazil, also highlighting alternative routes of VACV transmission, the factors involved in susceptibility to infection, and the natural history of the disease in humans and animals, and the potential for dissemination to urban environments.
正痘病毒（OPV）包括几种对人类和兽医医学具有重要意义的新兴病毒，包括引起南美洲牛痘（BV）爆发的牛痘病毒（VACV）。历史上，VACV 是研究最全面的病毒，但它的起源和自然宿主仍然未知。VACV 是天花疫苗的主要成分，在天花根除运动中广泛使用。天花被宣布根除后，赋予 OPV 免疫力的疫苗接种停止，有利于新的易感人群接触 OPV。VACV 感染是在与受感染的奶牛直接接触、最近接种疫苗的个体或通过其他暴露途径后自然发生的。在巴西，农村地区经常报告 VACV 爆发，主要影响农场动物和人类。最近的研究表明，野生动物在 VACV 传播链中发挥作用，探索野生啮齿动物作为储主的作用，促进 VACV 在农村地区的传播。此外，还探讨了 VACV 在城市环境中的循环及其对公共卫生的意义。在这篇综述中，我们讨论了巴西自然发生的 VACV 感染的历史、流行病学、生态学和临床方面，还强调了 VACV 传播的替代途径、感染易感性涉及的因素、人类和动物疾病的自然史，以及向城市环境传播的潜力。
