The changing reservoir of the zoonotic Hepatitis E virus in Türkiye: A novel potential threat to public health?

Pigs are considered the main reservoir of the zoonotic Hepatitis E virus (HEV) world-wide. However, in countries where there is no pork industry or pork consumption, the adaptation of zoonotic HEV (genotype 3) to different species has remained a controversial issue. The objective of our study was to investigate wild rodents as a potential new reservoir or host animal for the transmission of HEV to humans. In this study, HEV RNA was investigated in liver, lung, and spleen samples from 391 rodents of the genus Microtus collected from areas close to rural settlements and in blood samples taken from 50 anti-HEV IgG/IgM-positive individuals living in these regions. Sequence analyses and molecular characterizations of the HEV strains identified in both species were performed and phylogenetic trees were constructed. HEV RNA was detected in 8 of 50 human blood samples (16 %) and 6 of 391 rodents (1.5 %). When compared with the reference sequences obtained from NCBI, our rodent and human HEV strains were found to be genotype 3. It was determined that the rodent and human HEV sequences obtained from our study were 97.6–98.6 % identical. Reference rodent HEV strains formed a separate phylogenetic branch from the study strains and clustered within the Rocahepevirus group. Our study has shown that wild small mammals may play a role in the epidemiology of zoonotic HEV infection and therefore should be considered as potential reservoirs of the disease. Multidisciplinary collaboration (“One Health” approach) is required for the surveillance and control of HEV infection which threatens the public health.