Exploratory Epidemiological Study on Porcine Circovirus Type 2 Infection and Postweaning Multisystemic Wasting Syndrome in the Czech Republic

Abstract

The objective of our study was to diagnose the postweaning multisystemic wasting syndrome (PMWS) and to determine the prevalence of the disease in 33 swine herds in the Czech Republic using the results of laboratory examinations of 100 pigs expressing the signs of wasting at the end of 2007. Microscopic lesions associated with the presence of porcine circovirus 2 (PCV2) antigen were detected in the lymph nodes from 39 of 100 diseased pigs (39%). Based on individual assessment of severity of microscopic lymphoid lesions associated with high amounts of PCV2 antigen, PMWS was confirmed in 4 out of 39 pigs originating from 3 of 33 herds (9%). The epidemiological study indicates that PCV2 infections associated with PMWS disease are only sporadically present in the Czech Republic. Subsequently used real time PCR technique confirmed the relation between PMWS status at the individual pig level and PCV2 DNA concentration. PCV2 DNA load in lymph nodes of PMWS-affected pigs were about 3 logs higher than the levels detected in the PMWS-nonaffected group (P < 0.05). Other parallel viral infections (PRRSV, PPV) were detected by real time PCR techniques in 21 out of 39 PCV2 infected pigs (54%). The results of serological examination of blood samples collected during the necropsy of 100 pigs are suggestive of great prevalence of PCV2 infections in pig herds; nevertheless serum samples collected from individual pigs at a single point in time had a low diagnostic value.