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Neonatal diarrhoea

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  1. Neonatal diarrhoea Rota and coronaviruses October 6, 2010

  2. Rotavirus Coronavirus BVD Bredavirus Calicivirus Parvovirus Astrovirus Viral causes of diarrhoea in neonates

  3. Rotaviruses 4 to 14 days Coronavirus 4 to 30 Susceptibility of neonates 4 days 0 Colostral Antibodies in gut Susceptible period

  4. Vaccination of pregnant animals Colostrum for 2 weeks Management Prevention of viral diarrhea in calves

  5. vaccines against calf diarrhoea

  6. Rotaviruses

  7. Viruses with ds RNA genomes rotaviruses Reoviridae bluetongue virus african horse sickness Birnaviridae infectious bursal disease (chickens) infectious pancreatic necrosis (salmonid fish)

  8. 7 groups and many serotypes DS, segmented genome Unenveloped Inactivated by phenolic disinfectants Relatively insensitive to chlorination Persistence? Rotaviruses

  9. Rotavirus structure, serogroups and serotypes VP1 VP2 VP4 12 serotypes (P) VP3 VP6 VP7 14 serotypes (G) 7 Groups (A->G)

  10. Segmented genomes of rotaviruses implications electropherotyping

  11. Bovine rotaviruses Group A > B>C Most Group A, serotypes G6 and G10

  12. http://www.bovilis.com/diseases/ncd/pathogenesis.asp Pathogenesis lactase water Undigested milk water Shortened and fused villi

  13. Maintenance of rotaviruses in populations • stable in environment • mucosal antibody more important than systemic antibody • persistence and periodic shedding

  14. Detection of virus in fecal smears by FAT FAT for GrA (PDS) feces, $22 includes coronavirus jejunum, ileum, $38.50, includes coronavirus EM and immune EM antigen capture ELISAs (human test for Gr A rotaviruses) 80 to 95% sensitivity and specificity compared to RT-PCR (Maes et al. 2003, J. clin micro 41:290) Diagnosis

  15. Coronaviruses

  16. Viruses with +ve RNA genomes foot and mouth disease virus Picornaviridae porcine enteroviruses Caliciviridae feline calicivirus coronaviruses Coronaviridae Arteriviridae equine arterivirus Flaviviridae pestiviruses (BVD) Togaviridae equine encephalitis viruses

  17. SS +ve RNA Enveloped Epithelial cells of gut and respiratory tract Persistent infections Increased shedding in winter and at calving (bovine corona virus) Coronaviruses

  18. FAT on fecal or gut samples ($22.50-38.50/sample) EM ($45/sample) Diagnosis

  19. Transmissible gastroenteritis and respiratory disease in pigs Infectious bronchitis in poultry Feline enteric coronavirus (FEC) and infectious peritonitis (FIP) Ferret (catarrhal enteritis and FIP-like) SARS coronavirus Some other coronaviruses

  20. feline infectious peritonitis M.C. Horzinek and H. Lutz An update on FIP Veterinary Sience Tomorrow Jan, 2001 www.vetscite.org

  21. FIP • fatal disease of young (3-18 mo), or very old in multi-cat houses or catteries • not seen before 1950 • new virus? • old virus, new disease • systemic antibodies not protective, may even be harmful

  22. feline enteric coronavirus • closely related to dog, pig (TGE), human coronaviruses • species specific but K9CV can infect cats • two serotypes • serotype I • more common, 70-95% of isolates, does not cross react with K9CV • difficult to isolate

  23. FeCV, serotype 2 Both serotypes can lead to FIP causing strains

  24. epidemiology • Exposure to FeCV • 25% of cats from 1-2 cat households are seropositive • 75-100% of cats from catteries seropositive • susceptible cats become infected immediately following exposure • kittens can become infected in utero or soon after maternal antibodies drop below protective levels

  25. epidemiology (FIP) • 1:5,000 in 1-2 cat households • 1:20 in catteries • sporadic • clustered (2-3 cats) - rare • rarely epidemic • no gender or breed predisposition

  26. FIP pathogenesis FEC Mild diarrhoea or respiratory illness virus immune system persistent infection low level of replication in epithelial and lymphoid cells

  27. stress pregnancy in young queens elective surgery concurrent infections (FeLV, FIV ?) weaning, sale, shipment, adoption

  28. Virus immune system increased virus replication -> virulent mutants increased ability to grow in macrophages immune-mediated lysis of infected cells cytokines draw in more susceptible cells vascular permeability immune complex related damage

  29. M.C. Horzinek and H. Lutz An update on FIP Veterinary Sience Tomorrow Jan, 2001 www.vetscite.org

  30. clinical signs • common signs • chronic antibiotic unresponsive fever • progressive anorexia, weight loss • stunting of growth • blood abnormalities • progressive increase in serum proteins • increase in globulins • anemia • serum, urine brown due to bilirubin

  31. clinical signs • “wet” form (poor cell-mediated immunity) • peritonitis • pleuritis • “dry” form (some CMI) • granulomas • enlarged lymph nodes • cloudiness in eye • neurological signs • can change from dry to wet Sharif et al. 2010. Vet Med Int

  32. diagnosis • RT-PCR for FeCoV • Serology (ELISA for anti FeCoV antibodies) • prognosis? • no titre - no FIP but may still be infected • <100 - less chance of developing FIP • >100 - greater chance of getting FIP • increased globulins and protein (>35g/L) • cytology • degenerate and non-degenerate PMN, macrophages, some lymphocytes, protein background • FeCV positive cells (FAT)

  33. vaccine Primucell FIP Intranasal ts virus management early weaning and separation control