title: Atypical Porcine Pestivirus: A Possible Cause of Congenital Tremor Type A-II in Newborn Piglets.
abstract: 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.
authors: MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. ad.de.groof@merck.com.
authors: Ad
authors: A
authors: de Groof
authors: 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. m.deijs@amc.uva.nl.
authors: Martin
authors: M
authors: Deijs
authors: MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. LGuelen@aduro.com.|Current address: Aduro Biotech Europe, 5349AB, Oss, The Netherlands. LGuelen@aduro.com.
authors: Lars
authors: L
authors: Guelen
authors: MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. lotte.van.grinsven@merck.com.
authors: Lotte
authors: L
authors: van Grinsven
authors: 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. laura_v1310@hotmail.com.
authors: Laura
authors: L
authors: van Os-Galdos
authors: MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. wannes.vogels@merck.com.
authors: Wannes
authors: W
authors: Vogels
authors: MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. carmen.derks@merck.com.
authors: Carmen
authors: C
authors: Derks
authors: MSD Animal Health/Intervet Nederland bv., Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. toine.cruijsen@merck.com.
authors: Toine
authors: T
authors: Cruijsen
authors: MSD Animal Health/Intervet Nederland bv., Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. victor.geurts@merck.com.
authors: Victor
authors: V
authors: Geurts
authors: MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. mieke.vrijenhoek@merck.com.
authors: Mieke
authors: M
authors: Vrijenhoek
authors: MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. jannekesuijskens@hotmail.com.
authors: Janneke
authors: J
authors: Suijskens
authors: MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. petervandoorn@gmail.com.|Department of Farm Animal Health, Faculty of Veterinary Medicine, University of Utrecht, 3584CL, Utrecht, The Netherlands. petervandoorn@gmail.com.
authors: Peter
authors: P
authors: van Doorn
authors: Current address: Department of Biochemistry, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. l.vanleengoed@uu.nl.
authors: Leo
authors: L
authors: van Leengoed
authors: MSD Animal Health/Intervet International bv., Department Discovery & Technology, Wim de Körverstraat 35, P.O. Box 31, 5830AA Boxmeer, The Netherlands. carla.schrier@vaxxinova.com.|Current address: Vaxxinova GmbH, 48149, Münster, Germany. carla.schrier@vaxxinova.com.
authors: Carla
authors: C
authors: Schrier
authors: 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. c.m.vanderhoek@amc.uva.nl.
authors: Lia
authors: van der Hoek
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005243:Feces / Q000821:virology; D010576:Pestivirus / Q000302:isolation & purification / Q000472:pathogenicity*; D018182:Pestivirus Infections / Q000151:congenital / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000151:congenital*; D013997:Time Factors; D014202:Tremor / Q000151:congenital / Q000662:veterinary*; D014766:Viremia / Q000662:veterinary / Q000821:virology; D017201:Virus Shedding
keywords: pestivirus;  APPV;  congenital tremor;  persistent infection;  swine