Hepatitis E Virus: An emerging enigmatic and underestimated pathogen

Abstract

Hepatitis E virus (HEV) is an RNA virus causing hepatitis E disease. The virus is of one serotype but has diverse genotypes infecting both humans and animals. Based on evidence from seroprevalence studies, about 2 billion people are estimated to have been infected with HEV globally. HEV, therefore, poses a significant public health and economic challenge worldwide. HEV was discovered in the 1980s and was traced back to the 1955 – 1956 outbreak of hepatitis that occurred in India. Subsequently, several HEV epidemics involving thousands of individuals have occurred nearly annually in different countries in Asia and Africa. Initially, the virus was thought to be only enterically transmitted, and endemic in developing countries. Due to the environmental hygiene and sanitation challenges in those parts of the world. However, recent studies have suggested otherwise with the report of autochthonous cases in industrialised countries with no history of travel to the so-called endemic countries. Thus, suggesting that HEV has a global distribution with endemicity in both developing and industrialised nations. Studies have also revealed that HEV has multiple risk factors, and modes of transmission as well as zoonotic potentials. Additionally, recent findings have shown that HEV leads to severe disease, particularly among pregnant women. In contrast to the previous narration of a strictly mild and self-limiting infection. Studies have likewise demonstrated chronic HEV infection among immunocompromised persons. Consequent to these recent discoveries, this pathogen is considered a re – emerging virus, particularly in the developed nations. However, despite the growing public health challenges of this pathogen, the burden is still underestimated. The underestimation is often attributed to poor awareness among clinicians and a lack of routine checks for the disease in the hospitals. Thus, leading to misdiagnosis and underdiagnosis. Hence, this review provides a concise overview of epidemiology, diagnosis, and prevention of hepatitis E.

Global public health implications of human exposure to viral contaminated water

“…Hepatitis E virus (HEV) is a member of the family Hepeviridae and belongs to the Orthohepevirus genus and the Orthohepevirus A species. HEV is a non-enveloped, positive sense, ssRNA virus ( Denner, 2019 ) that causes significant acute hepatitis worldwide thereby resulting in sporadic infections and epidemics ( Raji et al, 2021 ). The infection is usually asymptomatic in the general population ( Khuroo and Kamili, 2003 ).…”

“…The virus is regarded as zoonotic with swine and other animals such as rabbits serving as the reservoir for human infections ( Ruggeri et al, 2013 ; Syed et al, 2018 ). Hepatitis E virus is another waterborne pathogen threatening global health in developing and developed countries ( Raji et al, 2021 ). Currently, eight HEV genotypes have been identified ( Upfold et al, 2021 ), and genotypes 1–4 and 7 are known to be the main threats to humans.…”

Placenta as a site of HEV replication and inflammatory cytokines modulating the immunopathogenesis of HEV in pregnant women

“…Conventionally, fecal-oral transmission has been attributed to person-to-person, or vertical transmission from mother to fetus, nosocomial spread, and by blood products transfusion. 20,21 As the site of infection is crucial for virus replication and dissemination, it can be one of the declining factors for recently identified infection routes. Studies indicated placenta as a source of TLR-induced cytokines and apoptosis, which play an important role as host immune factors.…”

Comparative prevalence of different types of viral hepatitis in the district Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan

“…Both hepatitis A virus (HAV) and hepatitis E virus (HEV) is transmitted through the fecal-oral route and sources of infection are contaminated water and food [2,4,5]. Both HAV and HEV are the most common causes of acute hepatitis in humans [6], and both are a serious public health concern in developing countries [7] and have multiple modes of transmission [8] as well as zoonotic potentials globally [8,9]. It is estimated that approximately 2 billion people are infected with HEV globally [8].…”

“…Both HAV and HEV are the most common causes of acute hepatitis in humans [6], and both are a serious public health concern in developing countries [7] and have multiple modes of transmission [8] as well as zoonotic potentials globally [8,9]. It is estimated that approximately 2 billion people are infected with HEV globally [8].…”