Porcine parvovirus, Erysipelothrix (E.) rhusiopathiae, and Leptospira (L.) interrogans are considered major etiologic agents of reproductive failure in pigs, causing economic loss in the swine industry. In this study, the safety and immunogenicity of a new octavalent inactivated vaccine were evaluated. The vaccine contained inactivated porcine parvovirus, E. rhusiopathiae, and six L. interrogans serovars (Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona). Safety test results showed no notable side effects or clinical signs after vaccination in mice, guinea pigs, and sows. In addition, we assessed immunogenicity of the vaccine in 25 sows under field conditions. The vaccinated group (n = 20) had a significantly higher antibody level than the non-vaccinated group (n = 5). Moreover, the stillbirth rate decreased in piglets born from vaccinated sows, resulting in an increased fertility rate. The results of this study demonstrate that the new octavalent inactivated vaccine can be applied safely and effectively to improve reproductive performance in sows.

Postweaning multisystemic wasting syndrome (PMWS), which was first identified in western Canada in 1991 and more recently in the United States, Europe and Asia, is an emerging disease in pigs. Porcine circovirus type 2 (PCV-2) is the primary infectious viral agent causing PMWS, but the full expression of the disease may require the presence of other agents. It is reported that there is apparent synergism between PCV-2 and porcine parvovirus (PPV) in increasing the severity of the clinical signs and lesions of PMWS. From January 2006 to May 2008, a total of the 154 lymph node samples were collected from 4~12 weeks old pigs which had been submitted to the College of Veterinary Medicine, Jeju National University, Korea. These pigs were diagnosed as PMWS on the basis of clinical and pathological examination from 48 commercial herds in Jeju Island. Based on the immunohistochemistry, porcine parvovirus was detected in 69 cases (44.8%) from 154 weaned or grower pigs. PPV antigens were detected in the cytoplasm of histiocytic cells multifocally infiltrated in the cortex and paracortex of lymph nodes. The results of this study clarify that PPV is prevalent in pigs with PMWS on Jeju Island. Therefore PPV is one of the most important co-agents in the development of naturally acquired PMWS. This study may be helpful to the control of this disease and to epidemiological aspects.

The role of porcine parvovirus (PPV) in inducing reproductive failure in swine has been extensively documented. However, information is not available as to the risk of ppv transmission by embryo transfer. Using the polymerase chain reaction (PCR) technique, PPV-specific DNA was detected in association with 4-day-old porcine embryos incubated in vitro in the presence of NADL-8 strain of PPV, despite attempts to rid the embryos of virus by either washing or treatment with pronase or trypsin. The presence of PPV in embryos collected from acutely infected swine was not detected by PCR, although PPV DNA was detected in the proximal portion of the reproductive tract during the early stages of infection. Viral-specific nucleic acid was not detected in embryos transferred from infected donors to seronegative recipients and retrieved and assayed on the 15th and 32nd days of gestation. Results of the use of PCR to detect PPV associated with swine female reproductive tract and embryos ascribe minimal risk to the transmission of PPV to seronegative recipients through embryo transfer.

To detect viral agents and isolate porcine circovirus 2 (PCV2), 60 samples of lung and lymph node were collected from 5 to 12 week-old pigs that had showed clinical signs of postweaning multisystemic wasting syndrome (PMWS). Polymerase chain reactions (PCRs) were conducted to identify the viral pathogens including PCV1, PCV2, porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV) that have been considered to be the causal agents of PMWS. Among 60 samples, PCV 2 was detected from 57 samples but no PCV 1 was detected.

The putative binding of porcine parvovirus (PPV) to semen components in vitro was examined along with the shedding pattern of PPV in oronasally infected boars. Porcine parvovirus DNA was determined to be bound to spermatozoa that had been incubated in vitro with PPV and washed to remove loosely adherent virus. To determine whether PPV was shed in the semen, four 8-month-old boars, seronegative for PPV, were inoculated oronasally with a virulent strain of PPV. Prior to virus inoculation, a catheter was surgically implanted in the vas deferens for the purpose of collecting cauda epididymal semen free of extrinsic contamination. Epididymal semen specimens were collected prior to inoculation and daily thereafter for 21 days. A fifth boar was inoculated oronasally with PPV, but semen was collected by electroejaculation twice weekly for an equal period of time. Reproductive glands and semen specimens from all boars were examined by nucleic acid hybridization for the presence of viral DNA. All boars seroconverted to PPV, as evidenced by serum antibody titers ranging from 512 to 8,192 hemagglutinating inhibition units/50 microliter. Porcine parvovirus DNA was detected in epididymal semen of 3 of 4 catheterized boars on postinoculation days 5 through 9, but not in semen obtained by electroejaculation. Viral DNA was consistently detected in tissue samples collected on postinoculation days 8 and 21 from the scrotal lymph nodes (4 of 5 boars) and epididymides (3 of 5 boars).