Hepatitis E virus seroprevalence of domestic pigs in Germany determined by a novel in-house and two reference ELISAs

• A capsid protein-based ELISA for the detection of HEV-specific IgG antibodies in domestic pigs was established.
• A carboxy-terminal segment of HEV capsid protein has the best diagnostic value.
• Comparison of the in-house test to a commercial IgG test shows a high concordance.
• The mean seroprevalence of domestic pigs from Germany was determined to be 42.7%.
• The seroprevalences diverge highly when viewed on herd level.

Autochthonous hepatitis E virus (HEV) infections by zoonotic transmission of genotype 3 (GT3) have been reported increasingly from industrialized countries. In this paper the development and validation of an IgG ELISA for the detection of HEV-specific antibodies in domestic pigs is described. Comparison of the diagnostic value of Escherichia coli-expressed HEV-GT3 capsid protein (CP) derivatives revealed a carboxy-terminal derivative as most suitable. Validation of the in-house assay using a commercially available IgG ELISA revealed a high diagnostic specificity and sensitivity. The average HEV seroprevalence of domestic pigs from Germany and the federal state Baden–Wuerttemberg determined by the in-house test was 42.7% and 50.3%, respectively. The seroprevalence in different districts of Baden–Wuerttemberg ranged from 34.9% to 60%, but from 0% to 100% between different herds. These data were compared to those achieved by two commercially available ELISA kits and an in-house ratHEV-based ELISA. In conclusion, the CP-based in-house test proved sensitive and specific, indicating that the ORF3-encoded protein might be dispensable for diagnostics. The novel assay also allowed a parallel analysis by a homologous ratHEV-derived antigen. Thus, the novel IgG ELISA represents a useful tool for future standardized seroprevalence studies in domestic pigs from Germany and other regions of Europe.