PDF(Pubmed)
Abstract：
Hepatitis E virus (HEV) is hyperendemic in South Asia and Africa accounting for half of total Global HEV burden. There are eight genotypes of HEV. Among them, the four common ones known to infect humans, genotypes 1 and 2 are prevalent in the developing world and genotypes 3 and 4 are causing challenge in the industrialized world. Asymptomatic HEV viremia in the general population, especially among blood donors, has been reported in the literature worldwide. The clinical implications related to this asymptomatic viremia are unclear and need further exploration. Detection of viremia due to HEV genotype 1 infection, apparently among healthy blood donors is also reported without much knowledge about its infection rate. Similarly, while HEV genotype 3 is known to be transmitted via blood transfusion in humans and has been subjected to screening in many European nations, instances of transmission have also been documented albeit without significant clinical consequences. Epidemiology of HEV genotype 1 in endemic areas often show waxing and waning pattern. Occasional sporadic occurrence of HEV infection interrupted by outbreaks have been frequently seen. In absence of known animal reservoir, where HEV exists in between outbreak is a mystery that needs further exploration. However, occurrence of asymptomatic HEV viremia due to HEV genotype 1 during epidemiologically quiescent period may explain that this phenomenon may act as a dynamic reservoir. Since HEV genotype 1 infection cannot cause chronicity, subclinical transient infection and transmission of virus might be the reason it sustains in interepidemic period. This might be the similar phenomenon with SARS COVID-19 corona virus infection which is circulating worldwide in distinct phases with peaks and plateaus despite vaccination against it. In view of existing evidence, we propose the concept of \"Dynamic Human Reservoir.\" Quiescent subclinical infection of HEV without any clinical consequences and subsequent transmission may contribute to the existence of the virus in a community. The potential for transmitting HEV infection by asymptomatic HEV infected individuals by fecal shedding of virus has not been reported in literature. This missing link may be a key to Pandora\'s box in understanding epidemiology of HEV infection in genotype 1 predominant region.
摘要：
戊型肝炎病毒（HEV）在南亚和非洲流行，占全球HEV总负担的一半。HEV有八种基因型。其中,已知感染人类的四种常见病毒，基因型1和2在发展中国家很普遍，基因型3和4在工业化世界引起了挑战。一般人群中的无症状HEV病毒血症，尤其是在献血者中，在全世界的文献中都有报道。与这种无症状病毒血症相关的临床意义尚不清楚，需要进一步探索。检测由HEV基因型1感染引起的病毒血症，显然，在健康的献血者中，也有报道对其感染率没有太多了解。同样，虽然已知HEV基因型3在人类中通过输血传播，并且已经在许多欧洲国家接受了筛查，尽管没有明显的临床后果,但也已记录了传播实例.流行地区的HEV基因型1的流行病学通常显示出打蜡和衰落的模式。经常会出现因爆发而中断的偶发性偶发性的HEV感染。在没有已知动物水库的情况下，HEV在爆发之间存在的地方是一个需要进一步探索的谜。然而,在流行病学静止期，由于HEV基因型1引起的无症状HEV病毒血症的发生可以解释这种现象可能是一个动态的水库。由于HEV基因型1感染不能引起慢性，亚临床短暂感染和病毒传播可能是其在血脂间期持续的原因。这可能是与SARSCOVID-19冠状病毒感染类似的现象，尽管接种了疫苗，但它在全球范围内以不同的阶段传播，具有高峰和平台。鉴于现有证据,我们提出了“动态人类水库”的概念。“HEV的静态亚临床感染，没有任何临床后果，随后的传播可能导致该病毒在社区中的存在。文献中尚未报道过无症状HEV感染个体通过病毒的粪便脱落传播HEV感染的可能性。这个缺失的环节可能是Pandora了解基因型1优势区域HEV感染流行病学的关键。
