Beiras Camila G, Malembi Emile, Escrig-Sarreta Roser, Ahuka Steve, Mbala Placide, Mavoko Hypolite M, Subissi Lorenzo, Abecasis Ana B, Marks Michael, Mitjà Oriol
Skin Neglected Tropical Diseases and Sexually Transmitted Infections Section, Fight Infectious Diseases Foundation, University Hospital Germans Trias i Pujol, Badalona, Spain; Department of Medicine, Universitat Autónoma de Barcelona, Bellaterra, Spain.
Program National Lutte Contre MPX-VHF, Kinshasa, Democratic Republic of the Congo.
Lancet. 2025 Jan 4;405(10472):86-96. doi: 10.1016/S0140-6736(24)02353-5. Epub 2024 Dec 12.
In this Review, we examine the concurrent outbreaks of mpox in Africa, focusing on clade 1a, the newly emerged clade 1b, and clade 2b lineage A, and how they differ from the 2022 global outbreak caused by clade 2b lineage B.1. Historically, clades 1a and 2a have caused sporadic, small outbreaks in central and west Africa, respectively, primarily through zoonotic transmission. Clade 2b first caused an outbreak in Nigeria in 2017, and later spread globally via sexual contact in 2022. In August, 2024, WHO declared a global health emergency due to the newly identified clade 1b outbreak in eastern Democratic Republic of the Congo. This outbreak has now expanded to several other countries and is spreading through direct and sexual contact in urban centres and refugee camps. Clades, route of exposure, infectious dose, and host immune response are the main factors influencing clinical presentation of mpox. For clades 1a and 2a, zoonotic transmission plays an important role, whereas for clades 1b and 2b, the spread occurs through sustained human-to-human transmission without zoonotic exposure. For both clades 1a and 2a, lesions have a generalised centrifugal distribution, whereas for clade 2b they are mainly localised to the anogenital area. For clade 1b, data are still emerging, but current cases show a mix of localised lesions and centrifugal distribution. The severity of the disease is higher for clade 1a (case fatality rate up to 12%) compared with other clades (case fatality rates 0-3·6%). Diagnostic challenges include false negative results for clade 1b with existing PCR assays and poor testing access in remote areas. Tecovirimat, the primary antiviral during the 2022 outbreak, has shown reduced effectiveness against clade 1a in preliminary study results, whereas its efficacy against other clades is still under investigation. The modified vaccinia Ankara-Bavarian Nordic vaccine has been shown to be up to 90% effective against clade 2b after two doses and is safe for children, although its effectiveness drops to 20% when used as post-exposure prophylaxis. Given the evolving nature of the monkeypox virus, ongoing research and strong public health responses are key to managing potential future outbreaks.
在本综述中，我们研究了非洲同时发生的猴痘疫情，重点关注1a分支、新出现的1b分支和2b分支A，以及它们与由2b分支B.1引起的2022年全球疫情有何不同。从历史上看，1a分支和2a分支分别在中非和西非引发了零星的小规模疫情，主要通过人畜共患病传播。2b分支于2017年首次在尼日利亚引发疫情，随后在2022年通过性接触在全球传播。2024年8月，世界卫生组织因刚果民主共和国东部新发现的1b分支疫情宣布全球卫生紧急情况。此次疫情现已蔓延至其他几个国家，并在城市中心和难民营通过直接接触和性接触传播。分支、接触途径、感染剂量和宿主免疫反应是影响猴痘临床表现的主要因素。对于1a分支和2a分支，人畜共患病传播起重要作用，而对于1b分支和2b分支，传播是通过持续的人际传播，无人畜共患病暴露。对于1a分支和2a分支，皮疹呈全身性离心性分布，而对于2b分支，皮疹主要局限于肛门生殖器区域。对于1b分支，数据仍在不断涌现，但目前的病例显示既有局限性皮疹，也有离心性分布。与其他分支（病死率0-3.6%）相比,1a分支疾病的严重程度更高（病死率高达12%）。诊断方面的挑战包括现有PCR检测对1b分支出现假阴性结果，以及偏远地区检测机会不足。2022年疫情期间的主要抗病毒药物特考韦瑞在初步研究结果中显示对1a分支的有效性降低，而其对其他分支的疗效仍在研究中。改良安卡拉痘苗-巴伐利亚北欧疫苗在接种两剂后对2b分支的有效性高达90%，对儿童安全，不过用作暴露后预防时有效性降至20%。鉴于猴痘病毒不断演变的特性,持续开展研究和强有力的公共卫生应对措施是应对未来潜在疫情的关键。
