Hepatitis E: Genotypes, strategies to prevent and manage, and the existing knowledge gaps

Abstract

Hepatitis E virus (HEV) is considered an emergent source of viral hepatitis worldwide, with an increasing burden of jaundice, liver failure, extrahepatic illnesses, and deaths in developed countries. With the scarcity of data from efficient animal models, there are still open‐ended questions about designing new models to study pathogenesis, types, virology, and evolution of these viruses. With an emphasis on available data and updates, there is still enough information to understand the HEV life cycle, pathogen interaction with the host, and the valuation of the role of vaccine and new anti‐HEV therapies. However, the World Health Organization (WHO) and the European Association for the Study of the Liver (EASL) preferred to stress prevention and control measures of HEV infections in animals, zoonotic transmission, and foodborne transmission. It is being reviewed that with current knowledge on HEV and existing prevention tools, there is an excellent room for in‐depth information about the virus strains, their replication, pathogenicity, and virulence. The current knowledge set also has gaps regarding standardized and validated diagnostic tools, efficacy and safety of the vaccine, and extrahepatic manifestations specifically in pregnant females, immunocompromised patients, and others. This review highlights the areas for more research exploration, focusing on enlisted research questions based on HEV infection to endorse the need for significant improvement in the current set of knowledge for this public health problem.

Label-Free Quantitative Analysis of Pig Liver Proteome after Hepatitis E Virus Infection

“…With reference to this aspect, it is important to underline that HEV-1 and HEV-2 have the possibility to infect only humans, while HEV-3 and HEV-4 represent zoonotic agents since they are able to infect domesticated animals, which therefore represent the main reservoirs in the transmission of the infection to humans. Besides this, it is also important to specify that HEV-4 is considered endemic in the Asian region, while HEV-3 is characterized by a global circulation [ 5 ].…”

Hepatitis E Virus (HEV) in Makkah, Saudi Arabia: A Population-Based Seroprevalence Study

“…The symptoms include jaundice, vomiting, nausea, abdominal pain, malaise, and anorexia, and they last typically for less than a month with recovery in nearly all individuals with an effective immune system [ 5 ]. The World Health Organization (WHO) estimates that 20 million new HEV cases occur annually, with 44,000 associated fatalities reported in 2015 [ 6 ]. HEV is mainly transmitted through the fecal-oral route by drinking contaminated water in endemic areas where HEV genotypes 1 and 2 are most prevalent [ 7 ], or by consuming contaminated animal products, particularly pork, in industrialized countries where genotypes 3 and 4 are most prevalent [ 8 , 9 ].…”

Acalculous cholecystitis is a common extrahepatic manifestation of hepatitis E and suggests a more serious condition

“…ORF2 encodes the capsid protein, that is used for vaccine preparation. ORF3 partially overlaps with ORF2 and encodes a multifunctional protein that may be involved in viral secretion [ 4 ]. Recently, a new ORF4 was discovered in genotype 1, which may mediate the interaction of the virus with the host protein to participate in its replication [ 5 ].…”