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 a...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.展开更多
目的了解广西地区猪、鼠、狗、猕猴和鱼5种动物戌型肝炎病毒（HEV）基因型和亚型分布。方法对广西地区猪、鼠、狗HEV抗体阳性血清170份,鼠肝组织150份,3月龄以下狗粪便标本80份,鱼胆汁标本120份,3月龄以下猪粪便标本129份,龙虎山自然景...目的了解广西地区猪、鼠、狗、猕猴和鱼5种动物戌型肝炎病毒（HEV）基因型和亚型分布。方法对广西地区猪、鼠、狗HEV抗体阳性血清170份,鼠肝组织150份,3月龄以下狗粪便标本80份,鱼胆汁标本120份,3月龄以下猪粪便标本129份,龙虎山自然景区猴粪便标本130份,用巢式逆转录聚合酶链反应法（RT-nPCR）检测戊型肝炎病毒核糖核酸（HEV RNA）,对RT-nPCR阳性扩增产物进行克隆测序,用Vector NTI Suite 9.0和Treeview软件与目前新分型方法所选参考序列进行核苷酸序列相似性比较和生物进化树分析。结果广西地区170份猪、鼠和狗血清HEV RNA检测均为阴性。在150份鼠肝组织,120份鱼胆汁标本,80份狗和130份猕猴粪便标本中均未检出HEV RNA;3月龄以下猪粪便标本HEV RNA阳性率10.08（13/129）。对13株猪HEV开放读码框架（ORF）1区部分核酸序列进行分析,其与Ⅰ、Ⅱ、Ⅲ和Ⅳ型HEV的相似性分别为73%～77%,76%～79%,76%～81%,82%～97%;与6个亚型的相似分别为4a：82%～94%;4b：82%～98%;4c：82%～87%;4d：81%～87%;4f：84%～86%;4g：81%～84%,其中2株与Ⅳa亚型相似性是高为82%～94%,11株与Ⅳb亚型相似性最高为82%～98%。结论广西地区猪HEV均为基因型4,2株属于基因型Ⅳa,Ⅱ株为Ⅳb。HEV在猪、鼠、狗血清、鼠肝组织、鱼胆汁、狗和猕猴粪便标本中均未检出。展开更多
文摘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.
文摘目的了解广西地区猪、鼠、狗、猕猴和鱼5种动物戌型肝炎病毒（HEV）基因型和亚型分布。方法对广西地区猪、鼠、狗HEV抗体阳性血清170份,鼠肝组织150份,3月龄以下狗粪便标本80份,鱼胆汁标本120份,3月龄以下猪粪便标本129份,龙虎山自然景区猴粪便标本130份,用巢式逆转录聚合酶链反应法（RT-nPCR）检测戊型肝炎病毒核糖核酸（HEV RNA）,对RT-nPCR阳性扩增产物进行克隆测序,用Vector NTI Suite 9.0和Treeview软件与目前新分型方法所选参考序列进行核苷酸序列相似性比较和生物进化树分析。结果广西地区170份猪、鼠和狗血清HEV RNA检测均为阴性。在150份鼠肝组织,120份鱼胆汁标本,80份狗和130份猕猴粪便标本中均未检出HEV RNA;3月龄以下猪粪便标本HEV RNA阳性率10.08（13/129）。对13株猪HEV开放读码框架（ORF）1区部分核酸序列进行分析,其与Ⅰ、Ⅱ、Ⅲ和Ⅳ型HEV的相似性分别为73%～77%,76%～79%,76%～81%,82%～97%;与6个亚型的相似分别为4a：82%～94%;4b：82%～98%;4c：82%～87%;4d：81%～87%;4f：84%～86%;4g：81%～84%,其中2株与Ⅳa亚型相似性是高为82%～94%,11株与Ⅳb亚型相似性最高为82%～98%。结论广西地区猪HEV均为基因型4,2株属于基因型Ⅳa,Ⅱ株为Ⅳb。HEV在猪、鼠、狗血清、鼠肝组织、鱼胆汁、狗和猕猴粪便标本中均未检出。
