Longitudinal study of hepatitis E virus infection in Spanish farrow-to-finish swine herds.
Hepatitis E is a zoonotic disease and is highly prevalent in European swine livestock. There is a need to compare the infection dynamics of hepatitis E virus (HEV) between herds with the same production system and determine the percentage of animals that could arrive infected at slaughter age. Therefore, a longitudinal study was performed in six Spanish farrow-to-finish affected farms. Twenty piglets per farm were monitored from nursery to slaughter. RT-PCR and serology techniques were applied to analyze longitudinally collected sera and/or faecal samples. Liver and bile samples were also taken at the abattoir. Anti-HEV IgM were firstly detected at 7 weeks of age in 5 farms whereas at 13 weeks of age in 1 farm (farm 2). At slaughter age 50-100% of pigs had seroconverted to anti-HEV IgG in the former 5 farms whereas in the other herd only 5% of pigs were IgG seropositive (farm 2). Six out of 96 livers and 5 out of 80 biles analyzed were HEV positive at the abattoir (total percentage of infected animals: 11.5%). All these positive animals had already seroconverted except 2 pigs of farm 2. Hence, pigs can be seronegative at slaughter age being infected during the latest fattening period. Manipulation of HEV-infected livers or other organs from pigs could be considered a possible route of transmission in Spanish abattoirs. This study represents the first longitudinal survey on swine HEV infection dynamics conducted in different herds.
Casas
Maribel
M
Centre de Recerca en Sanitat Animal (CReSA), Bellaterra, Barcelona, Spain. mcasas@creal.cat
Cortés
Raquel
R
Pina
Sonia
S
Peralta
Bibiana
B
Allepuz
Alberto
A
Cortey
Martí
M
Casal
Jordi
J
Martín
Marga
M
D000003:Abattoirs; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001646:Bile / Q000821:virology; D005243:Feces / Q000821:virology; D005260:Female; D016751:Hepatitis E / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary*; D016752:Hepatitis E virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008099:Liver / Q000821:virology; D058751:Livestock / Q000821:virology; D008137:Longitudinal Studies; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D017423:Sequence Analysis, RNA; D013030:Spain / Q000453:epidemiology; D013552:Swine / Q000821:virology*; D013553:Swine Diseases / Q000453:epidemiology / Q000276:immunology / Q000821:virology*
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012367:RNA, Viral