Prevalence of viruses associated with reproductive failure in Lithuanian swine herds

Abstract

Swine herds experience the huge losses because of reproductive failure (stillbirths, mummified fetuses, abortion, early embryonic death) due to viral diseases. The main viral pathogenes influencing swine reproduction are porcine reproductive and respiratory syndrome (PRRS) virus, classical swine fever (CSF) virus, Aujeszky’s disease (AD) virus, porcine parvovirus (PPV) and transmissible gastroenteritis (TGE) virus. Therefore, the study of epizootic situation have been performed for classical swine fever, Aujeszky’s disease, porcine reproductive and respiratory syndrome, porcine parvovirus infection and transmissible gastroenteritis in Lithuanian swine herds which had experienced the cases of reproductive failure in 2001. For the serological and virological studies the samples of blood sera and pathological material were taken in 2001-2002. The sera samples were tested due to: ELISA (IDEXX, USA; Test - Line, Czech Republic) with respect to AD ELISA (NARVAK, Russia with respect to CSF ELISA (IDEXX, USA; Test - Line, Czech Republic) with respect to PRRS and RT-PCR using primers to european and american strains of PRRSV. Haemagglutination inhibition reaction (Bioveta, Czech Republic) with respect PPV infection. Also the pathological material was tested due to: RT-PCR with respect to PRRSV Virus isolation and haemagglutination reaction with respect to PPV. Our study show that Lithuania is free from CSF and AD. All tested sera samples were negative for CSF virus and AD virus antibodies. The seroprevalence of PRRSV was significantly higher (61.6% ) in 1997 when PRRS disease first recognized in Lithuania and late in 1998-2001 the number of seropositive pigs have shown 38.7%, 40.7%, 36.1%, 29.2%, respectively. Furthermore, our studies indicated that the prevalence of PRRS virus antibody in the Lithuania swine population tested was relatively high (42.2 %) and swine farms with seropositive pigs were widely distribut[...].