Epidemiology of Mammalian Hepatitis E Virus Infection

Abstract

Mammalian hepatitis E virus (HEV), the etiological agent of hepatitis E in humans, is a recently discovered infectious agent. It was identified for the first time in 1983 using electron microscopy on a faecal specimen of a person infected with non-A, non-B enterically-transmitted hepatitis. Based on retrospective and prospective studies, HEV was long described as one of the leading causes of acute viral hepatitis in tropical and subtropical countries, whereas in developed countries hepatitis E was considered an imported disease from HEV hyperendemic countries. Data from studies conducted during the past decade have greatly shifted our knowledge on the epidemiology and clinical spectrum of HEV. Recently, it has been shown that contrary to previous beliefs, hepatitis E is also an endemic disease in several developed countries, particularly in Japan and in Europe, as evidenced by reports of high anti-HEV immunoglobulin G prevalence in healthy individuals and an increasing number of non-travel-related acute hepatitis E cases. Moreover, a porcine reservoir and growing evidence of zoonotic transmission have been reported in these countries. This review summarizes the current knowledge on the epidemiology and prevention of transmission of mammalian HEV.

Hepatitis E Virus Genotype 1 Infection of Swine Kidney Cells In Vitro Is Inhibited at Multiple Levels

“…Genotypes 1 and 2 infect humans and nonhuman primates exclusively, whereas genotype 3 and 4 viruses are enzootic, ubiquitous in swine, and present to a lesser extent in other human food sources, such as deer, rabbits, and cows (6,7). Genotype 1 commonly causes sporadic cases and epidemic waterborne acute hepatitis in developing countries with inadequate sanitation.…”

Seroprevalence of hepatitis E virus in Lithuanian domestic pigs and wildlife

“…Nowadays, hepatitis E is common not just in developing countries with inadequate water supply and environmental sanitation, but more autochthonous sporadic cases are diagnosed also in industrialized countries (Mansuy et al 2008;Kaba et al 2013), possibly mediated by the international trade of pigs, migration of wild animals, human contact with animals and their biological material, etc.…”

“…In contrast, a study from the UK indicated that 92.8% of 640 pigs sampled at slaughter were seropositive to HEV (Tedder 2014). Approximately 62% and 73% of serum from domestic pigs were positive for anti-HEV IgG antibodies in Estonia (Ivanova et al 2015) and Denmark (Kaba et al 2013), respectively.…”

“…The consumption of raw or undercooked contaminated meat of domestic pig, wild boar or deer and also seafood receiving sewage sludge or direct contact with infected animals have been identified as modes of transmission linked to autochthonous sporadic cases of acute hepatitis E in humans (Pavio et al 2010;Kaba et al 2013). Moreover, increased distribution and availability of game meat poses a major risk for foodborne transmission of HEV worldwide.…”

“…Up to date, at least seven genotypes of HEV have been reported, and five of them have been described in humans (HEV-1 and HEV-2 anthroponotic, HEV-3 and HEV-4 zoonotic, HEV-7 zoonotic potential is still being questioned) (Roth et al 2016). In contrast to humans, pigs and wild boar infected by HEV do not show obvious clinical manifestations.The consumption of raw or undercooked contaminated meat of domestic pig, wild boar or deer and also seafood receiving sewage sludge or direct contact with infected animals have been identified as modes of transmission linked to autochthonous sporadic cases of acute hepatitis E in humans (Pavio et al 2010;Kaba et al 2013). Moreover, increased distribution and availability of game meat poses a major risk for foodborne transmission of HEV worldwide.…”