Evidence of hepatitis E virus in milk and feces from rural cattle farms in Mazandaran province, Iran.

Hepatitis E virus (HEV) is a zoonotic pathogen that can cause acute viral hepatitis in both humans and animals. Some animals, such as swine, rabbits, cattle, and sheep are recognized as primary reservoirs of HEV. Recently, HEV has emerged as a significant public health concern in both industrialized and developing countries. Up to now, there is no information about zoonotic sources and prevalence of HEV in wild and domestic animals in Iran. This cross-sectional study aims to determine the prevalence of HEV. Multi-stage cluster sampling approach was used to collect 400 fecal swabs and 400 milk samples between September and February 2022. These samples were collected from rural cattle dairy farms in northern Iran. The viral genome was extracted, and semi-nested reverse transcription polymerase chain reaction was used to detect the HEV RNA genome. The overall estimated herd-level prevalence of HEV was found to be 6.25% (5/80, 95.00% CI: 2.06 - 13.99%). Among the 400 fecal and 400 milk samples obtained from 80 farms, the prevalence of HEV was 3.75% (3/80, 95.00% CI: 0.78 -10.57%), and 2.50% (2/80, 95.00% CI: 0.80 - 30.74%), respectively. Positive fecal samples were detected in Abbas-abad and Amol cities, while positive milk samples were found in Tonekabon City. Based on our findings, Hepatitis E is present in the cattle population of Mazandaran province, Iran. Further, more in-depth investigations are recommended due to the zoonotic nature of this disease. It is crucial to consider control and preventive measures in order to mitigate the spread of HEV.