7 ǀ CONCLUSION AND FUTURE PROSPECTS
In the past, the HEV was considered an infection of resources-limited
countries only. But after the discovery of new genotypes, different
animal reservoirs, the cross-species transmission had changed the
understanding of HEV worldwide and become a significant public health
problem. In recent years, the cases of HEV have been increased in
developed countries, which are mainly transmitted due to the consumption
of uncooked food. However, other modes of transmission including
visceral organs, sewage, fecal matter, discharges from the piggery, and
persons working there cannot be ignored for this zoonotic disease.
Genotype 1 & 2 are responsible for large outbreaks in low-income
countries, while genotype 3 & 4 are mainly responsible for sporadic
cases in the developed countries. Exposure to animal feces and
consumption of undercooked pork meat can cause HEV infection. HEV is
linked with the consumption of meat products from wild boars and pigs.
Therefore, the cross-species transmission is conceived the leading cause
of HEV infection in the developed countries.
Identification of virus in polluted pork products and mussels indicate
the circulation of HEV strains from water to food chain, and thus
necessitate a careful assessment of swine herds and food safety. Though
waterborne HEV-3 transmission remains uncertain, the occupational
contact with wastewater might be associated with autochthonous hepatitis
E, indicating the possible role of water in transmitting HEV-3. Animal
and human hosts of HEV-3 might pollute wastewater matrices by the
secreting faeces. HEV has also been identified in urban sewage samples
in various countries. HEV with a prevalence of G3 strains has been
monitored in effluent and influent water in drinking and WWTPs.
A better understanding of the viral dynamics and disease process can be
elucidated by developing models that are amicable to natural host or
disease pathology to support future research and minimize risks. Special
attention should be paid to vulnerable and high-risk groups including
pregnant women. In the absence of specific knowledge and lack of
interventions, general preventive measures can be helpful. Safety
measures and disease awareness are of worth importance while traveling
to HEV endemic areas. There is a dire need for effective treatment and
commercially available vaccines to prevent and control HEV infection
with particular emphasis on low-income countries as well as adopting the
concept of one health approach.