Atypical Porcine Pestivirus: A Possible Cause of Congenital Tremor Type A‐II in Newborn Piglets
Ad de Groof,
Martin Deijs,
Lars Guelen,
Lotte van Grinsven,
Laura van Os‐Galdos,
Wannes Vogels,
Carmen Derks,
Toine Cruijsen,
Victor Geurts,
Mieke Vrijenhoek,
Janneke Suijskens,
Peter van Doorn,
Leo van Leengoed,
Carla Schrier,
Lia van der Hoek
Affiliations
Ad de Groof
MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Martin Deijs
Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, 1105AZ, Amsterdam, The Netherlands
Lars Guelen
MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Lotte van Grinsven
MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Laura van Os‐Galdos
Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, 1105AZ, Amsterdam, The Netherlands
Wannes Vogels
MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Carmen Derks
MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Toine Cruijsen
MSD Animal Health/Intervet Nederland bv., Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Victor Geurts
MSD Animal Health/Intervet Nederland bv., Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Mieke Vrijenhoek
MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Janneke Suijskens
MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Peter van Doorn
MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Leo van Leengoed
Current address: Department of Biochemistry, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
Carla Schrier
MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands
Lia van der Hoek
Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, 1105AZ, Amsterdam, The Netherlands
Congenital tremor type A‐II in piglets has been regarded as a transmissible disease since the 1970s, possibly caused by a very recently‐described virus: atypical porcine pestivirus (APPV). Here, we describe several strains of APPV in piglets with clinical signs of congenital tremor (10 of 10 farms tested). Piglets on a farm with no history of congenital tremor were PCR‐negative for the virus. To demonstrate a causal relationship between APPV and disease, three gilts were inoculated via intramuscular injection at day 32 of pregnancy. In two of the three litters, vertical transmission of the virus occurred. Clinical signs of congenital tremor were observed in APPV‐infected newborns, yet also two asymptomatic carriers were among the offspring. Piglets of one litter were PCR‐negative for the virus, and these piglets were all without congenital tremors. Long‐term follow up of farm piglets born with congenital tremors showed that the initially high viremia in serum declines at five months of age, but shedding of the virus in feces continues, which explains why the virus remains present at affected farms and causes new outbreaks. We conclude that trans‐placental transmission of APPV and subsequent infection of the fetuses is a very likely cause of congenital tremor type A‐II in piglets.
