![]() ![]() Blood-borne transmission is rare but has been documented in some cases involving blood transfusions. Potential exists for food-borne transmission and some cases have been observed where consumption of raw or uncooked meat from wild boar and deer has led to HEV infection. The most common mode of transmission of HEV, also responsible for the majority of the HEV infection outbreaks, is through the faecal-oral route, usually by ingestion of contaminated water. MODE OF TRANSMISSION: Four modes of transmission of HEV infection have been reported: faecal-oral transmission, food-borne transmission, blood-borne transmission, and vertical transmission Footnote 5 Footnote 7. Several animal species have been experimentally infected with strains of HEV, including nonhuman primates such as African green monkeys, chimpanzees, cynomolgus macaques, owl monkeys, rhesus monkeys, tamarins, noninbred white mice and Wistar rats. HOST RANGE: Humans and animals, including swine Footnote 1. Documented epidemic outbreaks have occurred in Algeria, Ivory Coast, Ghana, Chad, Ethiopia, Somalia, Namibia, India, former Soviet Union, Nepal, Pakistan, Burma, Myanmar, China, Vietnam, Indonesia, and Mexico Footnote 8. ![]() In developed countries, HEV infection is generally reported from people who travel to HEV endemic or epidemic areas however, some cases of locally-acquired (autochthonous) HEV infection have been observed in non-endemic countries including USA, Australia, France, Greece, New Zealand, Italy, and UK. Males are more likely to develop clinical hepatitis when infected with HEV as compared to females. The attack rate of HEV is highest in young adults between ages of 15-40. There have been some cases of food-borne HEV infections, but the majority of confirmed cases have been associated with the consumption of water contaminated with feces. Outbreaks and sporadic cases of HEV have occurred over a large geographic area, most notable in regions with poor sanitation. Genotypes 3 and 4 are somewhat less pathogenic, infect humans, pigs, and other animal species, and are generally responsible for sporadic HEV infection cases within endemic and non-endemic regions. Genotypes 1 and 2 are considered more pathogenic, restricted to humans, and are responsible for the large majority of cases and outbreaks in endemic regions. Hepatitis caused by HEV is clinically indistinguishable from hepatitis A disease Footnote 6.ĮPIDEMIOLOGY: Phylogenetic studies indicate at least four distinct genotypes of HEV (1 – 4) based on geographical origin Footnote 5 Footnote 7. Analysis of serum specimens collected from volunteer blood donors shows that the prevalence of HEV varies from region-to-region but is higher in endemic countries/regions as compared to developed countries Footnote 5. Mortality rate due to infection by hepatitis E have been reported to be as high as 1 % Footnote 2 however, the mortality rate may reach up to 20 % in pregnant women with each passing trimester, making HEV infection the most severe hepatitis in pregnancy of all recognized hepatitis viruses. ![]() ![]() Anicteric hepatitis and cholestasis are also observed in some cases. PATHOGENICITY/TOXICITY: The disease caused by HEV is generally self-limiting with symptoms typical of acute viral hepatitis including, jaundice, malaise, anorexia, abdominal pain, nausea, fever, diarrhea, discoloured stool and/or urine, and hepatomegaly Footnote 1 Footnote 2 Footnote 3 Footnote 5. The surface of the particle consists of indentations and spikes, resulting in an appearance similar to that of calciviruses and it is often found in faeces of infected individuals Footnote 3. It is identified as a non-enveloped, icosahedral shaped sphere Footnote 3, approximately 27-34 nm in diameter, and consisting of a single-stranded, positive sense RNA molecule about 7.5 kilobases (kb) in length Footnote 1 Footnote 2 Footnote 4 Footnote 5. SYNONYM OR CROSS REFERENCE: HEV, enterically transmitted or enteric non-A non-B hepatitis (ENANB), epidemic non-A non-B hepatitis Footnote 1 Footnote 2 Footnote 3 Footnote 4, faecal-oral non-A non-B hepatitis, and A-like non-A non-B hepatitis.ĬHARACTERISTICS: Hepatitis E virus (HEV) is classified as the only member of the genus Hepevirus in the family Hepeviridae Footnote 2 Footnote 4. PATHOGEN SAFETY DATA SHEET - INFECTIOUS SUBSTANCES SECTION I - INFECTIOUS AGENT ![]()
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