Detection of hepatitis E virus genotypes 3 and 4 in donkeys in northern China.

BACKGROUND

Hepatitis E virus (HEV) is the causative agent of acute self-limiting hepatitis in humans in developing countries. Hepatitis E virus RNA was first detected in donkeys in Spain, but little is known about the possible presence of HEV in donkeys in China.

OBJECTIVES

To investigate the prevalence of HEV in donkeys in northern China.

STUDY DESIGN

Investigation of the prevalence of HEV in donkeys using serological, molecular and phylogenetic approaches.

METHODS

A total of 401 donkey serum specimens were tested for serological and molecular detection of HEV via enzyme-linked immunosorbent assay and quantitative reverse transcription polymerase chain reaction. The amplified products were cloned in pMD18-T vector and sequenced. The alignment and phylogenetic analysis of partial HEV ORF2 genes were compared with the corresponding sequences of the obtained HEV representative strains.

RESULTS

Serological results showed that 49 donkeys (12.22%, 95% CI: 9.18-15.83%) were positive for anti-HEV-specific antibodies, and 17 donkeys (4.24%, 95% CI: 2.49-6.70%) were positive for HEV viral RNA. On the basis of sequence alignment and phylogenetic analysis, all isolated HEV strains belonged to genotype 3 (HEV-3) or HEV-4, sharing more than 76.2-96.3% identities with 67 other HEV representative strains of HEV-1 to HEV-8.

MAIN LIMITATIONS

Further studies about the prevalence of HEV in organs or faecal samples from donkeys are needed to evaluate the possible role of HEV reservoir and to determine the risk factors associated with the transmission of this zoonotic virus in donkeys in China.

CONCLUSIONS

This is the first report documenting the molecular analysis of donkey HEV strains worldwide and the serological evidence of HEV infection in donkeys in northern China. The results suggest that young donkeys are more susceptible to HEV infection compared with older donkeys. Further investigation is required to determine whether donkeys should be considered reservoirs for zoonotic HEV. The Summary is available in Chinese - see Supporting information.