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

Epidemiological characteristics of swine pulmonary Pneumocystis (P.) carinii and concurrent infections were surveyed on Jeju Island, Korea, within a designated period in 172 pigs submitted from 54 farms to the Department of Veterinary Medicine, Jeju National University. The submitted cases were evaluated by histopathology, immunohistochemistry, PCR/RT-PCR, and bacteriology. P. carinii infection was confirmed in 39 (22.7%) of the 172 pigs. Histopathologically, the lungs had moderate to severe lymphohistioctyic interstitial pneumonia with variable numbers of fungal organisms within lesions. Furthermore, porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV-2) co-infection was a common phenomenon (12.8%, 20.5%, and 48.7% were positive for PRRS, PCV-2, or both, respectively, as determined by PCR/RT-PCR). Infection was much more concentrated during winter (December to March) and 53.8% of the infected pigs were 7- to 8-weeks old. In addition, three pigs showed co-infection with bacteria such as Pasteurella multocida and Streptococcus suis. The results of the present study suggest that the secondary P. carinii infection is common following primary viral infection in swine in Korea. They further suggest that co-infection of P. carinii might be enhanced by the virulence of primary pathogens or might have synergistic effects in the pigs with chronic wasting diseases.
Aging ; Animals ; *Circovirus/pathogenicity ; Incidence ; Pasteurella Infections/complications/epidemiology/veterinary ; Pasteurella multocida/i ; *Pneumocystis carinii/immunology/pathogenicity ; Pneumonia, Pneumocystis/complications/epidemiology/physiopathology/*veterinary ; Porcine Postweaning Multisystemic Wasting Syndrome/complications/*epidemiology ; Porcine Reproductive and Respiratory Syndrome/*epidemiology ; *Porcine respiratory and reproductive syndrome virus/pathogenicity ; Prevalence ; Republic of Korea/epidemiology ; Reverse Transcriptase Polymerase Chain Reaction ; Sea ; Streptococcal Infections/complications/epidemiology/veterinary ; Streptococcus suis/i ; Sus scrofa ; Swine Diseases/epidemiology/virology

A porcine reproductive and respiratory syndrome virus (PRRSV) was obtained from clinic samples. Genes 5 and 6 encoding for the viral glycoprotein 5 and a membrane protein of the PRRSV designated as HH08 were amplified by reverse transcription-PCR. These sequences were compared with reference sequences derived from different geographical locations. The results indicated that the virus belongs to the North American type rather than European. Comparative analyses of the genetic diversity between the PRRSV isolate HH08 and other Chinese as well as foreign reference strains of PRRSV were discussed based on the sequence comparison and the topology of phylogenetic trees constructed in this study.
Animals ; Base Sequence ; China/epidemiology ; Gene Expression Regulation, Viral/physiology ; Genetic Variation ; Molecular Sequence Data ; *Phylogeny ; Porcine Reproductive and Respiratory Syndrome/epidemiology/virology ; Porcine respiratory and reproductive syndrome virus/*genetics/*metabolism ; Sequence Alignment ; Swine ; Viral Envelope Proteins/genetics/*metabolism ; Viral Matrix Proteins/genetics/*metabolism