Age-related and regional differences in the prevalence of hepatitis E virus-specific antibodies in pigs in Germany.
An increasing number of acute autochthonous human hepatitis E virus (HEV)-infections was noticed in Germany and other developed countries, most likely the result of a zoonotic virus transmission from pig, wild boar and deer. Currently there is still a lack of profound data concerning the actual prevalence of HEV-specific antibodies in domestic pig herds in Germany, in particular for regions with high pig density, and its age-dependency. 2273 domestic pig sera were collected in 2011 mainly from Bavaria, North Rhine-Westphalia and Lower Saxony from areas having a high pig density. Initially, 420 randomly selected pig sera were tested in three commercially available and in two in-house HEV-antibody ELISAs. 43.6% (183/420) to 65.5% (275/420) of the sera were demonstrated to be reactive against human pathogenic HEV genotypes 1 and/or 3. The majority of sera reacted only weakly or not at all with the rat HEV antigen with very few sera showing a stronger reactivity to this antigen compared to the genotype 3 antigen. The results of all three HEV-IgG tests, i.e. the PrioCHECK(®) HEV Ab porcine ELISA kit, the ID Screen(®) Hepatitis E Indirect Multi-species ELISA kit and the genotype 3 in-house ELISA were in good accordance. Therefore, the remaining sera were tested using the PrioCHECK(®) HEV Ab porcine ELISA kit. Samples with a borderline result were finally determined by application of the conjugate-modified recomLine HEV IgG assay. A total of 1065 of the 2273 sera (46.9%) were found to be anti-HEV IgG-positive. While 38.4% (306/796) of fatteners (age between 3 and 9 months) exhibited HEV-specific antibodies, 51.4% (759/1477) of sows (age older than 9 months) exhibited anti-HEV antibodies (P<0.001). Fatteners kept in Southern Germany had a significantly higher HEV IgG prevalence compared to fatteners kept in the high pig density federal states North Rhine-Westphalia and Lower Saxony but also in German federal states with a low pig density. In conclusion, the present study clearly demonstrates that a high percentage of domestic pigs in Germany have had contact with HEV. Seroprevalence depends on the pig's age and herd origin with the most significant regional variations for fatteners. The presence of anti-HEV-free herds may indicate that it is feasible to establish and sustain HEV-free pig herds. HEV seroprevalence still depends on the assay used for testing. This demonstrates an urgent need for test validation.
Institute for Infection Medicine, Christian Albrecht University of Kiel and University Medical Center Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany; Department of Virology and Antiviral Therapy, Jena University Hospital, Friedrich Schiller University Jena, 07740 Jena, Germany. Electronic address: krumbholz@infmed.uni-kiel.de.
Andi
A
Krumbholz
Sebastian
S
Joel
Anne
A
Neubert
Paul
P
Dremsek
Ralf
R
Dürrwald
Reimar
R
Johne
Andreas
A
Hlinak
Mario
M
Walther
Jeannette
J
Lange
Peter
P
Wutzler
Andreas
A
Sauerbrei
Rainer G
RG
Ulrich
Roland
R
Zell
D000367:Age Factors; D000818:Animals; D005843:Geography; D005858:Germany / Q000453:epidemiology; D006508:Hepatitis Antibodies / Q000097:blood*; D016751:Hepatitis E / Q000453:epidemiology / Q000662:veterinary*; D016752:Hepatitis E virus / Q000502:physiology; D007074:Immunoglobulin G / Q000097:blood; D016036:Seroepidemiologic Studies; D012698:Serologic Tests / Q000592:standards / Q000662:veterinary; D034421:Sus scrofa / Q000821:virology; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology*
D006508:Hepatitis Antibodies; D007074:Immunoglobulin G
Age-dependency; Domestic pig; Germany; HEV; IgG; Regional variations