Hepatitis E virus seroprevalence and risk factors for individuals in working contact with animals

Background: In industrial countries genotypes 3 and 4 of HEV are detected in swine, wild boar, deer and rabbits, and they are associated with autochthonous infections suggesting the existence of zoonotic HEV infections, compatible with the putative involvement of undercooked pork and big game products as a source of infection.

Objectives: To evaluate the prevalence of anti-HEV antibodies in different population groups in contact with animals and to investigate risk factors for HEV infection.

Study design: Serum samples were collected from 859 healthy French subjects, including pig farm workers, forestry workers and individuals without working contact with animals (control group). In addition, 58 swine veterinarians were included in the study. Subjects were interviewed using a structured questionnaire, and anti-HEV antibodies were investigated using a sensitive and specific sandwich ELISA.

Results: Anti-Hepatitis E virus (HEV) antibodies were detected in 26% of control population, and in 36% and 44% of forestry and pig farm workers, respectively. In addition, an increase in seroprevalence from the north to the south of France was observed (30.2% versus 40.7%). Consumption of pork liver sausage (AOR 4.4, p < 10(-4)), occupational contact with animals (AOR 1.58, p = 0.038 for forestry workers and AOR 2.51, p < 10(-4) for pig farm workers), and living in southern France (AOR 1.47, p = 0.02), were independent risk factors. Wearing working gloves and boots might reduce HEV infection.

Conclusions: Occupational exposure to animals and consuming raw or undercooked pork liver sausage or pork liver play a significant role in HEV transmission in industrial countries.