Porcine reproductive and respiratory syndrome virus and porcine circovirus type 2 infections in wild boar (Sus scrofa) in southwestern Germany

Samples were collected from 203 wild boars (Sus scrofa) hunted in Baden-Wurtemburg, Germany from November-January 2008 and 2009. Samples from the lung and tonsil were analyzed by quantitative polymerase chain reaction (qPCR) for porcine reproductive and respiratory syndrome virus (PRRSV) type 1 (European type) and type 2 (American type). A qPCR to detect porcine circovirus type 2 (PCV2)-specific genome was performed on tissue homogenates including lung, tonsils, and inguinal lymph nodes. Serum samples were tested for antibodies against PRRSV and PCV2 by enzyme-linked immunosorbent assay (ELISA). No PRRSV was detected in any of the 203 samples and one sample had detectable antibodies against PRRSV. We detected PCV2 in organ materials from 103 wild boars with a prevalence of 50.7%. The number of wild boars positive for PCV2 by PCR varied according to the population density of wild boars among woodlands. More positive samples were detected in woodlands with a high density of wild boars. We found no correlation between the number of PCV2-positive wild boars and the density of domestic pigs in the surrounding area. The number of wild boars positive for antibodies against PCV2 by the INGEZIM Circovirus IgG/IgM test kit was low (53 sera positive for IgG- and three sera positive for IgM-antibodies) in comparison to the higher positive results from the INGEZIM CIRCO IgG test kit (102 positive and 12 inconclusive results).