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第17号公告板 - Winter 2003
VirologyPMWS-Circovirus-PDNS
NAUWYNCK H, SANCHEZ R, MEERTS P, MATEUSEN B, PENSAERT M
New insights in the pathogenesis of PCV2 infections in fetuses.
Proceedings of the 1st APVS Congress, Seoul, September 2003, 3-6
Late abortion, mummification, stillbirth and prolonged gestation are the main reproductive symptoms associated with PCV2 infection. A summary of the research performed on PCV2-related reproductive failure is provided together with the main relative statements. PCV2 infection of fetuses is a rather rare event but seronegative gilts and sows are more at risk to be affected by reproductive failure than infection-immune sows. When dealing with possible routes of infection, there is yet no indication of transplacental transmission of the virus to fetuses whereas semen containing infectious virus was demonstrated to infect both seronegative dam and fetuses after insemination. Intrafetal inoculation of PCV2 at different stage of gestation showed that fetuses inoculated at 57 days of gestation were more susceptible to PCV2 infection compared to those inoculated at 75 or 92 days of gestation. Such increased susceptibility was associated with higher virus titers and higher number of infected cells and myocarditis whereas fetuses inoculated later showed no pathological lesions at day 21pi. The clinical and pathological outcome of these fetuses were also different since those inoculated at 57 days of gestation died, became mummified and transmitted PCV2 to the other fetuses of the litter, those inoculated at 75 days of gestation were stillborn at birth while those inoculated at 92 days of gestation did not show any pathology. Cardiomyocytes, hepatocytes and cells of the monocyte/macrpophage lineage were found to be the target cells of PCV2 in these fetuses.
