During the period from January to December of 2001, a total of 3,391 swine sera were submitted to our laboratory from 256 farms for the diagnosis of porcine reproductive and respiratory syndrome (PRRS). The antibody to porcine reproductive and respiratory syndrome virus (PRRSV) was tested by the indirect immunofluorescent antibody (IFA) test. Of the 256 farms tested, 230 farms (89.8%) were positive for the PRRSV antibody. The overall seroprevalence of the PRRSV antibody was 52.1% (1765/3391). Most of the pigs seemed to be infected with PRRSV at around 50 to 60 days old. The seroprevalence of the antibody became higher with age, and peaked at around 100 days old. More than one-third of the adult pigs, including boars, gilts, and sows, was positive for the PRRSV antibody. The infection of PRRSV was chronic and confined to growers and/or finishers in most farms. However, the antibody was detected in all production phases at some farms.
Age Factors ; Animals ; Antibodies, Viral/blood ; Female ; Fluorescent Antibody Technique, Indirect/veterinary ; Korea/epidemiology ; Male ; Porcine Reproductive and Respiratory Syndrome/diagnosis/epidemiology/*virology ; Porcine respiratory and reproductive syndrome virus/immunology/*isolation &purification ; Seroepidemiologic Studies ; Sex Factors ; Swine

Porcine reproductive and respiratory syndrome virus(PRRSV)0, porcine circovirus type 2(PCV-2) and porcine parvovirus (PPV)0 infections were investigated as possible causes of the postweaning multisystemic wasting syndrome(PMWS). Specific primers for RT-PCR and PCR were designed for the differential detection of PRRSV, PCV-2 and PPV. Using PCR, these viruses were detected in homogenized tissue samples from pigs that had respiratory of reproductive problems in the time period between 1998 and 2000; the overall prevalences were: PRRSV 31.4%, PCV-2 46.5%, and PPV 8.1%. PCV-2 was also detected in aborted fetal tissues.
Aborted Fetus/virology ; Animals ; Base Sequence ; Circoviridae Infections/diagnosis/epidemiology/*veterinary ; Circovirus/genetics/isolation&purification ; DNA Primers ; Diagnosis, Differential ; Korea/epidemiology ; Parvoviridae Infections/diagnosis/epidemiology/*veterinary ; Parvovirus, Porcine/genetics/isolation&purification ; Polymerase Chain Reaction/methods/veterinary ; Porcine Reproductive and Respiratory Syndrome/diagnosis/*epidemiology ; Porcine respiratory and reproductive syndrome virus/genetics/isolation & purification ; Prevalence ; Respiratory Tract Infections/veterinary/virology ; Reverse Transcriptase Polymerase Chain Reaction/methods/veterinary ; Sequence Homology ; Swine ; Swine Diseases/diagnosis/*epidemiology ; Wasting Syndrome/*veterinary/virology