Phylogenetic and Case‐Control Study on Hepatitis E Virus Infection in Germany

Abstract

Background. Hepatitis E is a classic water-borne disease in developing countries. In Germany, hepatitis E virus (HEV) infections are notifiable. The number of non-travel-associated infections has increased in recent years, but the route of transmission in most is unknown. Our objective was to determine risk factors for autochthonous HEV infections in Germany.Methods. Cases of HEV met clinical definitions and were confirmed by laboratory analysis (defined as detection of HEV by polymerase chain reaction [PCR] or immunoglobulin M by serologic testing). PCR products from blood or stool samples were genotyped for phylogenetic analysis. A case-control study included case subjects with autochthonous HEV infection and matched control subjects who were randomly recruited from a population-based telephone list.Results. From May 2006 through August 2007, 76 of 96 persons for whom HEV infection had been reported to the routine surveillance system were interviewed. Sixty-six persons had disease that fulfilled the inclusion criteria: 45 (68%) had autochthonous infection, and 21 (32%) had travel-associated disease. Genotypes 3 or 4 were present in 15 of 15 persons with autochthonous infection, and genotype 1 was present in 8 of 9 persons with travel-associated infection. In conditional logistic regression involving 45 case subjects and 135 control subjects, consumption of offal (41% vs. 19%; odds ratio [OR], 2.7; 95% confidence interval [CI], 1.2-6.2) and wild-boar meat (20% vs. 7%; OR, 4.3; 95% CI, 1.2-15.9) were independently associated with autochthonous HEV infection.Conclusion. Hepatitis E is endemic in Germany and likely exists as a food-borne zoonosis. Implicated meat products should be investigated to provide recommendations for preventive measures.

Detection of hepatitis E virus genome in pig livers in Antioquia, Colombia

“…In Germany, the consumption of offal, such as pig liver and parts of wild animals (wild boar), was associated with native infections by HEV (Wichmann et al, 2008). Similar cases were reported from the consumption of venison with HEV in Japan (Tei et al, 2003).…”

“…Pig liver is a common dietary component in many countries and is used as an ingredient in sausages or is grilled for consumption. In Germany, pig liver consumption was associated with HEV infection in a case study (Wichmann et al, 2008). Additionally, the consumption of raw sausages containing pig liver was identified as the probable source of an HEV infection in France (Colson et al, 2010).…”

Transmission routes and risk factors for autochthonous hepatitis E virus infection in Europe: a systematic review

“…In a risk factor EL2 analysis using a structured questionnaire, dried sausages and uncooked shellfish (mussels, oysters, or both) were considered risk factors associated with cases in The Netherlands and France, respectively, but these studies did not use controls [19,51]. In the EL3 case-control study in Germany, Wichmann et al found that eating any offal or wild boar was independently associated with autochthonous HEV infection [52]. No significant association was found for other food products from other animals including shellfish.…”

“…In the EL2 enhanced surveillance conducted by Borgen et al in The Netherlands it was specifically asked if any family members or close contacts had signs of hepatitis in the months preceding or following the disease period of the cases, but no positive responses were elicited and a limited contact investigation found no evidence of HEV infection [19]. During the enhanced surveillance conducted for the case-control study in Germany, unstructured household investigations identified five additional IgM-positive HEV cases in three households of autochthonous cases [52], one of whom was PCR-positive. All were asymptomatic or complained only of mild abdominal pain or fatigue.…”

Hepatitis E virus (HEV)-specific T-cell responses are associated with control of HEV infection

“…3 At least five different HEV genotypes have been described, with four of them being able to infect humans. HEV genotype 3 has frequently been associated with zoonotic infections, 4,5 whereas HEV genotypes 1 and 2 appear to primarily infect humans. We recently confirmed the anthropo-zoonotic capacity of HEV genotype 3 by experimentally infecting pigs with a serum sample of a chronic HEV-infected patient.…”