Seroprevalence in blood donors reveals widespread, multi-source exposure to hepatitis E virus, southern France, October 2011

The apparent seroprevalence of hepatitis E Virus (HEV) varies greatly among developed countries depending on the geographical area and the sensitivity of immunoassays. We used a validated assay to determine the prevalence of HEV IgG and IgM antibodies among 3,353 blood donors living in southern France, who gave blood during the two first weeks of October 2011 and participated in the study. Demographic and epidemiological information was collected using a specific questionnaire. We also screened 591 samples for HEV RNA. Overall IgG seroprevalence was 39.1% and varied from 20% to 71.3% depending on the geographical area (p < 0.001) while IgM seroprevalence was 3.31%. Anti-HEV IgG was significantly correlated with increasing age (p < 0.001), eating uncooked pork liver sausages (p < 0.001), offal (p = 0.003), or mussels (p = 0.02). Anti-HEV IgM was associated with being male (p = 0.01) and eating uncooked pork liver sausages (p = 0.02). HEV RNA was detected in one of the 99 anti-HEV IgM-positive samples, but in none of the 492 anti-HEV IgM-negative samples. HEV is hyperendemic in southern France. Dietary and culinary habits alone cannot explain the epidemiology of HEV in this region, indicating that other modes of contamination should be investigated.