Paton David J, Di Nardo Antonello, Knowles Nick J, Wadsworth Jemma, Pituco Edviges M, Cosivi Ottorino, Rivera Alejandro M, Kassimi Labib Bakkali, Brocchi Emiliana, de Clercq Kris, Carrillo Consuelo, Maree Francois F, Singh Raj K, Vosloo Wilna, Park Min-Kyung, Sumption Keith J, Ludi Anna B, King Donald P
The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
Pan American Foot-and-Mouth Disease and Veterinary Public Health Center, Pan American Health Organization/World Health Organization (PANAFTOSA/VPH-PAHO/WHO), Rio de Janeiro, Brazil.
Virus Evol. 2021 Mar 19;7(1):veab009. doi: 10.1093/ve/veab009. eCollection 2021 Jan.
Foot-and-mouth disease (FMD) is a highly contagious animal disease caused by an RNA virus subdivided into seven serotypes that are unevenly distributed in Asia, Africa, and South America. Despite the challenges of controlling FMD, since 1996 there have been only two outbreaks attributed to serotype C, in Brazil and in Kenya, in 2004. This article describes the historical distribution and origins of serotype C and its disappearance. The serotype was first described in Europe in the 1920s, where it mainly affected pigs and cattle but as a less common cause of outbreaks than serotypes O and A. No serotype C outbreaks have been reported in Europe since vaccination stopped in 1990. FMD virus is presumed to have been introduced into South America from Europe in the nineteenth century, although whether serotype C evolved there or in Europe is not known. As in Europe, this serotype was less widely distributed and caused fewer outbreaks than serotypes O and A. Since 1994, serotype C had not been reported from South America until four small outbreaks were detected in the Amazon region in 2004. Elsewhere, serotype C was introduced to Asia, in the 1950s to the 1970s, persisting and evolving for several decades in the Indian subcontinent and for eighteen years in the Philippines. Serotype C virus also circulated in East Africa between 1957 and 2004. Many serotype C viruses from European and Kenyan outbreaks were closely related to vaccine strains, including the most recently recovered Kenyan isolate from 2004. International surveillance has not confirmed any serotype C cases, worldwide, for over 15 years, despite more than 2,000 clinical submissions per year to reference laboratories. Serology provides limited evidence for absence of this serotype, as unequivocal interpretation is hampered by incomplete intra-serotype specificity of immunoassays and the continued use of this serotype in vaccines. It is recommended to continue strengthening surveillance in regions of FMD endemicity, to stop vaccination against serotype C and to reduce working with the virus in laboratories, since inadvertent escape of virus during such activities is now the biggest risk for its reappearance in the field.
口蹄疫（FMD）是一种由RNA病毒引起的高度传染性动物疾病，该病毒分为七种血清型，在亚洲、非洲和南美洲分布不均。尽管控制口蹄疫存在挑战，但自1996年以来，仅在2004年巴西和肯尼亚发生过两起因C型血清型导致的疫情。本文描述了C型血清型的历史分布、起源及其消失情况。该血清型于20世纪20年代在欧洲首次被描述，在欧洲主要感染猪和牛，但与O型和A型血清型相比，引发疫情的情况较少见。自1990年停止疫苗接种以来，欧洲未报告过C型血清型疫情。口蹄疫病毒据推测于19世纪从欧洲传入南美洲，不过C型血清型是在南美洲还是欧洲进化而来尚不清楚。与在欧洲的情况一样，该血清型的分布不如O型和A型广泛，引发的疫情也较少。自1994年以来，南美洲未报告过C型血清型疫情，直到2004年在亚马逊地区检测到四起小规模疫情。在其他地方，C型血清型于20世纪50年代至70年代传入亚洲，在印度次大陆持续存在并演变了几十年，在菲律宾存在了18年。C型血清型病毒在1957年至2004年间也在东非传播。许多来自欧洲和肯尼亚疫情的C型血清型病毒与疫苗株密切相关，包括2004年最近从肯尼亚分离出的毒株。尽管每年向参考实验室提交超过2000份临床样本，但国际监测在全球范围内15年多来未确认任何C型血清型病例。血清学提供的该血清型不存在的证据有限，因为免疫测定的血清型内特异性不完全以及该血清型仍在疫苗中使用，妨碍了明确的解释。建议继续加强口蹄疫流行地区的监测，停止针对C型血清型的疫苗接种，并减少实验室中对该病毒的操作，因为在此类活动中病毒意外泄漏现在是其在野外再次出现的最大风险。
