Marchio Agnès, Sitbounlang Philavanh, Deharo Eric, Paboriboune Phimpha, Pineau Pascal
Institut Pasteur, Université Paris Cité, Unité "Organisation Nucléaire et Oncogenèse", INSERM U993, 75015 Paris, France.
Centre d'Infectiologie Lao-Christophe Mérieux (CILM), Vientiane 3888, Laos.
Microorganisms. 2023 Aug 31;11(9):2204. doi: 10.3390/microorganisms11092204.
Genotype I, the penultimate HBV genotype to date, was granted the status of a bona fide genotype only in the XXIst century after some hesitations. The reason for these hesitations was that genotype I is a complex recombinant virus formed with segments from three original genotypes, A, C, and G. It was estimated that genotype I is responsible for only an infinitesimal fraction (<1.0%) of the chronic HBV infection burden worldwide. Furthermore, most probably due to its recent discovery and rarity, the natural history of infection with genotype I is poorly known in comparison with those of genotypes B or C that predominate in their area of circulation. Overall, genotype I is a minor genotype infecting ethnic minorities. It is endemic to the Southeast Asian Massif or Eastern Zomia, a vast mountainous or hilly region of 2.5 million km spreading from Eastern India to China, inhabited by a little more than 100 million persons belonging primarily to ethnic minorities speaking various types of languages (Tibeto-Burman, Austroasiatic, and Tai-Kadai) who managed to escape the authority of central states during historical times. Genotype I consists of two subtypes: I1, present in China, Laos, Thailand, and Vietnam; and I2, encountered in India, Laos, and Vietnam.
基因I型是迄今为止倒数第二种被确认的乙肝病毒基因型，在经过一段时间的犹豫之后，直到21世纪才被确认为真正的基因型。犹豫的原因在于基因I型是一种复杂的重组病毒，由来自三种原始基因型A、C和G的片段组成。据估计，基因I型在全球慢性乙肝病毒感染负担中所占比例极小（<1.0%）。此外，很可能由于其发现较晚且较为罕见，与在其传播区域占主导地位的基因B型或C型相比，基因I型感染的自然史鲜为人知。总体而言，基因I型是一种感染少数民族的次要基因型。它在东南亚地块或东掸邦呈地方性流行，这是一个从印度东部延伸至中国的广袤山区或丘陵地区，面积达250万平方公里，居住着1亿多人口，主要是少数民族，他们说各种语言（藏缅语族、南亚语系和泰-卡岱语系），在历史时期设法摆脱了中央政权的统治。基因I型由两个亚型组成：I1型存在于中国、老挝、泰国和越南；I2型在印度、老挝和越南被发现。
