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.