Hepatitis E virus was not detected in feces and milk of cows in Hebei province of China: No evidence for HEV prevalence in cows

Abstract

Hepatitis E virus (HEV) is an important human pathogen, with pigs and other species serving as natural animal reservoirs. Recently, the report of detection of genotype 4 HEV in dairy milk with high positive rate in Yunnan province of China has attracted extensive attention. To assess the zoonotic risk of cows as HEV reservoir and transmission of HEV through dairy milk, 467 fecal samples of cows, 276 fresh milk samples, and 140 retail milk samples were collected across Hebei Province, China, from March 2017 to May 2018, and detected for HEV RNA. Fecal samples of rabbit or pig were also collected for HEV detection from farms of mixed farming with cows or farms neighboring cow farms. HEV RNA was not detected in any cow feces or in any milk samples, but 9.3% feces of pigs and 18.9% feces of rabbits were positive for HEV RNA. In addition, all of the dairy milk samples undergone HEV antigen and anti-HEV antibody detections, but none was positive. Phylogenetic analysis showed that all of the HEV isolates from pigs belonged to genotype 4 and those from rabbits were genotype 3-rabbit HEV. The results indicate that, currently in Hebei province of China, HEV is not apparently prevalent in cows and hence there is no zoonotic transmission risk through dairy milk towards humans, albeit the genotype 4 and 3 (rabbit) HEV are prevalent in pigs and rabbits respectively.