Rinderpest vpm

Rinderpest is a severe disease in dairy animals like cattle and buffalo.

1. RINDERPEST CATTLE PLAGUE Dr Ashish Tanwer Teaching Associate V. C.C, C.V.A.S Bikaner

2. INTRODUCTION  Acute, highly contagious, viral disease of cattle, domesticated buffalo and other ruminants  Characterized by Fever Necrotic stomatitis Oral erosions Diarrhoea Lymphoid necrosis High mortality

3. ETIOLOGY  Family: Paramyxoviridae  Genus: Morbillivirus  Negative sense, Single stranded RNA virus  Only 1 serotype of this virus  Three genetically distinct lineages  African Lineages 1 and 2  Asian Lineage 3  All are immunologically identical  Antigenically related to PPR, CD & measles

4. HOST  Most cloven-hooved animals (order Artiodactyla) are susceptible to rinderpest virus to some degree  Cattle, water buffalo, yaks, African buffalo, giraffes, warthogs and Tragelaphinae (spiral-horned antelope) are particularly susceptible to disease  Gazelles, sheep and goats - mildly susceptible  Rinderpest is rare in camelids

5. TR A NSMISSION  By direct or close indirect contact between infected and susceptible animals  Virus is excreted by the infected host in their urine, feces, nasal discharge  Airborne transmission is limited but possible  Feed and water contaminated with the secretions of infected host  RPV is sensitive to direct sunlight thus fomites are not a viable means of transmission  Failure of the virus to persist outside the body – easy to control

6.  Because rinderpest virus is inactivated quickly by autolysis and putrefaction, this virus is destroyed within 24 hours in carcasses  Freezing or chilling of the carcass in some climates could slow these processes and allow the virus to survive longer  High morbidity and mortality

7. SOURCE OF VIRUS  Incubation period is around – 1 to 2 weeks  Shedding of virus begins 1–2 days before pyrexia, in tears, nasal secretions, saliva, urine and faeces  Blood and all tissues are infectious before the appearance of clinical signs  During periods of clinical disease, high levels of RPV can be found in expired air, nasal and ocular discharges, saliva, faeces, semen, vaginal discharges, urine and milk  Infection is via the epithelium of the upper or lower respiratory tract  No carrier state

8. VIRUS- U R T ,t o nsi l s lymphnode VIREMIA Lymphocytes Apoptosis & necrosis Lymphopenia Replication in epithelial cells of alimentary tract Focal, necrotic stomatitis & enteritis Severe dehydration Parasitic or bacterial D e a th PATHOGENESIS

9. PRODROMAL PHASE  Lasts approximately 3 days  Pyrexia of between 40 and 41.5°c  Partial anorexia  Depression  Reduction of rumination  Constipation  Lowered milk production, Increase of respiratory and cardiac rate  Congestion of visible mucosae  Serous to mucopurulent ocular and nasal discharges  Drying of the muzzle

10. EROSIVE PHASE  Development of necrotic mouth lesions  at height of fever:  flecks of necrotic epithelium appear on the lower lip and gum  In rapid succession may appear on the upper gum and dental pad  Underside of the tongue  Cheeks and cheek papillae  Hard palate; erosions or blunting of the cheek papillae

11. Bovine, oral mucosa. There is severe diffuse necrosis ulceration of the dental pad; mandibular mucosa contains smaller erosions

12. Bovine, hard palate. Palate erosion .

13. Bovine, hard palate. The mucosa contains many small, coalescing, pale to dark red erosions or foci of necrosis .

14. Bovine, oral mucosa. There are numerous erosions on and between the buccal papillae.

15. GASTROINTESTINAL SIGNS  Appear when the fever drops or about 1–2 days after the onset of mouth lesions  Diarrhoea is usually copious and watery at first  later may contain mucus, blood and shreds of epithelium; accompanied, in severe cases, by tenesmus  Diarrhoea or dysentery leads to dehydration, abdominal pain, abdominal respiration, and weakness  Terminal stages of the illness, animals may become recumbent for 24–48 hours prior to death

16. Shooting Diarrhoea

17. The mucosa is hyperemic and covered by abundant mucopurulent exudate . BOVINE TRACHEA

18. The mucosa is hemorrhagic and edematous, and the Peyer's patch is depressed (necrosis). BOVINE ILEUM

19. The mucosa is edematous and contains many small hemorrhages and shallow erosions. BOVINE COLON There are many petechiae on the crests of the mucosal folds, and there are several small blood clots on the mucosal surface.

20. The mucosa contains multiple longitudinal linear hemorrhages BOVINE COLON

21. Erosions with ulceration; dark areas of mucosal necrosis and hemorrhage zebra striping’ - haemorrhages of the longitudinal folds of the large intestine

22.  Some animals die while showing severe necrotic lesions  High fever and diarrhoea  Others after a sharp fall in body temperature  Often to subnormal values  In rare cases, clinical signs regress by day 10 and recovery occurs by day 20–25

23. PERACUTE FORM No prodromal signs except  high fever (>40–42°C)  sometimes congested mucous membranes  death within 2–3 days  This form occurs in highly susceptible young and new born animals

24. MILD SUBACUTE OR ENDEMIC FORM  Clinical signs limited to one or more of the classic signs  Usually no associated diarrhoea  May show a slight, serous, ocular or nasal secretion  Fever: variable, short-lived (3–4 days) and low (38–40°C)  No actual depression; animals may continue to graze, water and trek  Low or no mortality; except in highly susceptible species

25. ATYPICAL FORM  Irregular pyrexia and mild or no diarrhoea  Fever may remit slightly in the middle of the erosive period, and 2–3 days later, return rapidly to normal accompanied by a quick resolution of the mouth lesions, a halt to the diarrhoea and an uncomplicated convalescence  The lymphotropic nature of RPV leads to immunosuppression and favours recrudescence of latent infections and/or increased susceptibility to other infectious agents

26. SHEEP AND GOAT  Variable signs; some pyrexia, anorexia and minor ocular discharge  Sometimes diarrhoea  Asian RPV strains can be transmitted to cattle by contact with infected small ruminants

27. DIFFERENTIAL DIAGNOSIS  Bovine viral diarrhoea/mucosal disease  Malignant catarrhal fever  Infectious bovine rhinotracheitis  Foot and mouth disease  Papular stomatitis  Vesicular stomatitis  Contagious bovine pleuropneumonia  Theileriosis  Salmonellosis  Necrobacillosis  Paratuberculosis  Arsenic poisoning

28. LABORATORY DIAGNOSIS SAMPLES  pyrexia - blood  Spleen, prescapular or mesenteric lymph nodes of dead animals chilled to sub-zero temperatures for virus isolation  base of the tongue, retropharyngeal lymph node and third eyelid - histopathology and immunohistochemistry  Ocular and nasal secretions –prodromal phase

29. VIRUS ISOLATION  RPV virus can be cultured from the leukocyte fraction of whole blood (heparin or EDTA) or uncoagulated blood  Virus can also be isolated from samples of the spleen, prescapular or mesenteric lymph nodes of dead animals  presence of syncytial cell formation, and cells with intranuclear viral inclusion bodies  R inde r pe s t antigens c a n be demon s tr a ted in t he f ormali n - fixed tissues by immunoperoxidase staining

30. DIAGN O SIS For rapid differentiation between rinderpest and PPR Antigen detection by agar gel immunodiffusion Differential immunocapture ELISA Lineage identification using the reverse-transcription PCR VIRUS NEUTRALIZATION TEST –Gold standard ELISA CHROMATOGRAPHIC STRIP TEST Developed for assisting field personnel in investigating suspected outbreaks of rinderpest Any positive result should be treated as indicating a highly suspicious rinderpest case that must be immediately be subjected to a thorough investigation

31. TRE A TMENT  Treatment is ineffective  Vaccines are of no value in treating already infected animals

32. CONTROL AND ERADICATION  Slaughter and rigid quarantine measures  In endemic areas, control used to be by annual vaccination and surveillance  vaccine prepared from one strain will protect against all other strains  Rinderpest vaccine protects goats against infection with the virus of PPR  Prevention of the introduction of ruminants from known infected areas

33. DISINFE C TION  Rinderpest virus can be killed by most common disinfectants including phenol, cresol, sodium hydroxide (2% for 24 hours) and lipid solvents  The FAO recommends that premises, equipment and clothing be cleaned, then decontaminated with oxidizing agents such as sodium or calcium hypochlorite, or alkalies such as sodium hydroxide or sodium carbonate  Faeces and effluents should be treated with sodium carbonate, before they are burned or buried  Pasteurization or heat treatment can inactivate the virus in milk.

34. Th e rmo V ax  The new vaccine, named ThermoVax ,  shelf life of 30 days outside the cold-chain and it was required to hold the minimum titre for 14 days at 45°C, sufficient to dramatically extend the reach of field vaccination programmes  The transfer of technology to African production facilities led to the commercial availability of ThermoVax in quantities sufficient for rinderpest eradication by 1992.