Congenital tremor type A 3 in pigs: an hereditary sex-linked cerebrospinal hypomyelinogenesis

Abstract Background Congenital tremor (CT) type A-II is a neurological disorder characterized by tremor of the head and body of newborn piglets. The suggested causative agent of the disease is the recently found atypical porcine pestivirus (APPV). The virus has been detected in piglets suffering from congenital tremor in central Europe, South and North America and in China but no studies has so far been performed in the Nordic countries. The overarching goal of this study was to investigate if APPV is present in the brain tissue of Swedish piglets suffering from congenital tremor. From June 2017 – June 2018, 15 piglets from four Swedish farms with ongoing outbreaks of congenital tremor and 13 piglets with splay leg originating from four different farms, were investigated for presence of APPV RNA in brain tissue. Matched healthy control piglets (n=8) were also investigated. Two APPV-specific RT-qPCR methods targeting the NS3 and NS5B region, respectively, were used. A retrospective study was performed on material from Swedish piglets with congenital tremor sampled in 2004 (n = 11) and 2011/2012 (n = 3) using the described APPV-specific RT-qPCR methods. The total number of piglets with signs of CT in this study was 29. Results Atypical porcine pestivirus-RNA was detected in 93% (27/29) of the piglets suffering from congenital tremor. All piglets with congenital tremor from 2004 (n = 11) and 2012 (n = 3) were PCR-positive with respect to APPV, whereas, all of the healthy controls (n = 11) were negative. The piglets with congenital tremor sampled 2017-2018 had an odds ratio of 91,8 (95% CI 3.9128 to 2153.7842, z = 2.807, P = 0.0050) to test positive for APPV by qRT-PCR compared to the healthy piglets (Fishers exact test p < 0.0001). These findings make it interesting to continue investigating APPV in the Swedish pig population. Conclusion This is the first description of atypical porcine pestivirus in piglets suffering from congenital tremor type A-II in Sweden and the Nordic countries. The virus has been present in the Swedish pig population since at least 2004.

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Pestivirus K (Atypical Porcine Pestivirus): Update on the Virus, Viral Infection, and the Association with Congenital Tremor in Newborn Piglets

Viruses ◽

10.3390/v12080903 ◽

2020 ◽

Vol 12 (8) ◽

pp. 903 ◽

Cited By ~ 1

Author(s):

Alais M. Dall Agnol ◽

Alice F. Alfieri ◽

Amauri A. Alfieri

Keyword(s):

Immune Response ◽

Viral Infection ◽

Type A ◽

Prevention Measures ◽

Pig Production ◽

Newborn Piglets ◽

The Family ◽

Control And Prevention ◽

And Control ◽

Congenital Tremor

The atypical porcine pestivirus (APPV) belongs to the species Pestivirus K of the genus Pestivirus and the family Flaviviridae, and it has been associated with congenital tremor (CT) type A-II in newborn piglets. Although APPV was discovered in 2015, evidence shows that APPV has circulated in pig herds for many years, at least since 1986. Due to the frequently reported outbreaks of CT on different continents, the importance of this virus for global pig production is notable. Since 2015, several studies have been conducted to clarify the association between APPV and CT. However, some findings regarding APPV infection and the measures taken to control and prevent the spread of this virus need to be contextualized to understand the infection better. This review attempts to highlight advances in the understanding of APPV associated with type A-II CT, such as etiology, epidemiology, diagnosis, and control and prevention measures, and also describes the pathophysiology of the infection and its consequences for pig production. Further research still needs to be conducted to elucidate the host’s immune response to APPV infection, the control and prevention of this infection, and the possible development of vaccines.

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Atypical Porcine Pestivirus: A Possible Cause of Congenital Tremor Type A‐II in Newborn Piglets

Viruses ◽

10.3390/v8100271 ◽

2016 ◽

Vol 8 (10) ◽

pp. 271 ◽

Cited By ~ 56

Author(s):

Ad de Groof ◽

Martin Deijs ◽

Lars Guelen ◽

Lotte van Grinsven ◽

Laura van Os‐Galdos ◽

...

Keyword(s):

Type A ◽

Newborn Piglets ◽

Congenital Tremor ◽

Possible Cause

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Detection of Atypical porcine pestivirus in Swedish pigs with congenital tremor type A-II

10.21203/rs.2.16766/v1 ◽

2019 ◽

Author(s):

Hedvig Stenberg ◽

Magdalena Jacobson ◽

Maja Malmberg

Keyword(s):

Odds Ratio ◽

Type A ◽

Nordic Countries ◽

Ns5b Region ◽

Healthy Controls ◽

Exact Test ◽

Qrt Pcr ◽

Matched Healthy Control ◽

Healthy Control ◽

Congenital Tremor

Abstract Background Congenital tremor type A-II is a neurological disorder characterized by tremor of the head and body of new-born piglets. The suggestive causative agent of the disease is the recently found atypical porcine pestivirus. The virus has been detected in piglets suffering from congenital tremor in central Europe, South and North America and in China but no studies has so far not been performed in the Nordic countries, hence, the aim of this study was to investigate the prevalence of atypical porcine pestivirus in Swedish piglets. From June 2017 – June 2018, 15 piglets from four Swedish farms with ongoing outbreaks of congenital tremor, and 13 piglets with splay leg, from four different farms, were investigated for presence of APPV RNA in brain tissue. Matched healthy control piglets (n=8) were also studied. Two APPV-specific RT-qPCR:s targeting the NS3 and NS5B region, respectively, were used. A retrospective study was performed in the same manner on material from Swedish piglets with congenital tremor sampled in 2004 (n=11) and 2011/2012 (n=6). Results Atypical porcine pestivirus-RNA was detected in 93% (27/29) of the piglets suffering from congenital tremor. All samples from piglets with congenital tremor from 2004 (n = 11) and 2012 (n = 3) were PCR-positive with respect to APPV. All of the healthy controls (n=8) were negative for APPV. The piglets with congenital tremor sampled 2017-2018 had an odds ratio of 271 (95% CI 12.1 to 6096.8, z = 3.5, P = 0.0004) to test positive for APPV by qRT-PCR compared to the healthy piglets (Fishers exact test p < 0.0001). These findings make it interesting to continue investigating APPV in pigs in Sweden, as most of the virus details is unknown to date. Conclusion This is the first description of atypical porcine pestivirus in piglets with congenital tremor type A-II in Sweden and the Nordic countries. The virus has been present in the Swedish pig population since at least 2004.

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Detection of Atypical porcine pestivirus in Swedish pigs with congenital tremor type A-II

10.21203/rs.2.16766/v2 ◽

2020 ◽

Author(s):

Hedvig Stenberg ◽

Magdalena Jacobson ◽

Maja Malmberg

Keyword(s):

Brain Tissue ◽

Odds Ratio ◽

Type A ◽

Nordic Countries ◽

Exact Test ◽

Qrt Pcr ◽

Matched Healthy Control ◽

Healthy Control ◽

Congenital Tremor ◽

The Brain

Abstract Background Congenital tremor (CT) type A-II is a neurological disorder characterized by tremor of the head and body of new-born piglets. The suggested causative agent of the disease is the recently found atypical porcine pestivirus. The virus has been detected in piglets suffering from congenital tremor in central Europe, South and North America and in China but no studies has so far been performed in the Nordic countries. The overarching goal of this study was to investigate if atypical porcine pestivirus are present in the brain tissue of Swedish piglets suffering from congenital tremor. From June 2017 – June 2018, 15 piglets from four Swedish farms with ongoing outbreaks of CT and 13 piglets with splay leg originating from four different farms, were investigated for presence of APPV RNA in brain tissue. Matched healthy control piglets (n=8) were also studied. Two APPV-specific RT-qPCR methods targeting the NS3 and NS5B region, respectively, were used. A retrospective study was performed on material from Swedish piglets with CT sampled in 2004 (n = 11) and 2011/2012 (n = 3) using the described APPV-specific RT-qPCR methods. The total number of piglets with signs of CT in this study was 29. Results Atypical porcine pestivirus-RNA was detected in 93% (27/29) of the piglets suffering from congenital tremor. All piglets with congenital tremor from 2004 (n = 11) and 2012 (n = 3) were PCR-positive with respect to APPV, whereas, all of the healthy controls (n = 11) were negative. The piglets with CT sampled 2017-2018 had an odds ratio of 271 (95% CI 12.1 to 6096.8, z = 3.5, P = 0.0004) to test positive for APPV by qRT-PCR compared to the healthy piglets (Fishers exact test p < 0.0001). These findings make it interesting to continue investigating APPV in the Swedish pig population. Conclusion This is the first description of atypical porcine pestivirus in piglets suffering from congenital tremor type A-II in Sweden and the Nordic countries. The virus has been present in the Swedish pig population since at least 2004. Keywords: congenital tremor, type A-II, atypical porcine pestivirus, splay legs, Sweden, pigs, piglets.

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A review of congenital tremor type A-II in piglets

Animal Health Research Reviews ◽

10.1017/s146625232000002x ◽

2020 ◽

Vol 21 (1) ◽

pp. 84-88 ◽

Cited By ~ 1

Author(s):

Hedvig Stenberg ◽

Magdalena Jacobson ◽

Maja Malmberg

Keyword(s):

Neurological Disease ◽

Current Knowledge ◽

Clinical Signs ◽

Type A ◽

Porcine Circovirus ◽

Placental Barrier ◽

Type B ◽

Causative Agents ◽

The Central Nervous System ◽

Congenital Tremor

AbstractCongenital tremor (CT) is a neurological disease that affects new-born piglets. It was described in 1922 and six different forms, designated type AI-V and type B, are described based on the causative agents, as well as specific histological findings in the central nervous system (CNS). The various forms present with identical clinical signs consisting of mild to severe tremor of the head and body, sometimes complicated with ataxia. By definition, all A-forms have hypomyelination of the CNS, whereas there are no histopathological lesions with the B-form. The cause of the A-II form was long unknown, however, at present several different viruses have been proposed as the causative agent: porcine circovirus-II (PCV-II), astrovirus, PCV-like virus P1, and atypical porcine pestivirus (APPV). Currently, APPV is the only virus that has been proven to fulfill Mokili's Metagenomic Koch's Postulates. Following infection of the pregnant sow, the virus passes the placental barrier and infects the fetus. Interestingly, no clinical signs of disease have been associated with APPV in adult pigs. Furthermore, other viruses cannot be ruled out as additional potential causes of CT. Given the increased interest and research in CT type A-II, the aim of this review is to summarize current knowledge.

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Biological and Morphological Studies on Low-Leukemia-Strain Mice with Hodgkin's-Like Neoplasia Induced by Serial Cell-Free Transmission of Leukemic Organs of SJL/J Strain Mice

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100792 ◽

1968 ◽

Vol 26 ◽

pp. 210-211

Author(s):

S. Fujinaga ◽

K. Maruyama ◽

C.W. Williams ◽

K. Sekhri ◽

L. Dmochowski

Keyword(s):

Tissue Culture ◽

Type A ◽

Reticulum Cell ◽

Type B ◽

Viral Origin ◽

Serial Transfer ◽

Strain Mouse ◽

Morphological Studies ◽

Cell Neoplasm ◽

Free Material

Yumoto and Dmochowski (Cancer Res.27, 2098 (1967)) reported the presence of mature and immature type C leukemia virus particles in leukemic organs and tissues such as lymph nodes, spleen, thymus, liver, and kidneys of SJL/J strain mice with Hodgki's-like disease or reticulum cell neoplasm (type B). In an attempt to ascertain the possibility that this neoplasia may be of viral origin, experiments with induction and transmission of this neoplasm were carried out using cell-free extracts of leukemic organs from an SJL/J strain mouse with spontaneous disease.It has been possible to induce the disease in low-leukemia BALB/c and C3HZB strain mice and serially transfer the neoplasia by cell-free extracts of leukemic organs of these mice. Histological examination revealed the neoplasia to be of either reticulum cell-type A or type B. Serial transfer is now in its fifth passage. In addition leukemic spleen from another SJL/J strain mouse with spontaneous reticulum cell neoplasm (type A) was set up in tissue culture and is now in its 141st serial passage in vitro. Preliminary results indicate that cell-free material of 39th tissue culture passage can reproduce neoplasia in BALB/c mice.

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Hepatitis A Antigen in Liver, Bile and Stool

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100115328 ◽

1975 ◽

Vol 33 ◽

pp. 340-341

Author(s):

D.R. Jackson ◽

J.H. Hoofnagle ◽

A.N. Schulman ◽

J.L. Dienstag ◽

R.H. Purcell ◽

...

Keyword(s):

Hepatitis A ◽

Liver Enzymes ◽

Hepatitis A Virus ◽

Type A ◽

Initial Study ◽

Virus Like Particle ◽

Elevated Liver Enzymes ◽

Ag Particles ◽

Ag Particle ◽

Human Stool

Using immune electron microscopy Feinstone et. al. demonstrated the presence of a 27 nm virus-like particle in acute-phase stools of patients with viral hepatitis, type A, These hepatitis A antigen (HA Ag) particles were aggregated by convalescent serum from patients with type A hepatitis but not by pre-infection serum. Subsequently Dienstag et. al. and Maynard et. al. produced acute hepatitis in chimpanzees by inoculation with human stool containing HA Ag. During the early acute disease, virus like particles antigenically, morphologically and biophysically identical to the human HA Ag particle were found in chimpanzee stool. Recently Hilleman et. al. have described similar particles in liver and serum of marmosets infected with hepatitis A virus (HAV). We have investigated liver, bile and stool from chimpanzees and marmosets experimentally infected with HAV. In an initial study, a chimpanzee (no.785) inoculated with HA Ag-containing stool developed elevated liver enzymes 21 days after exposure.

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