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1. RABIES
SUBMITTED BY-: RUDRA NARAYAN
TO THE DEPT OF PATHOLOGY,CVSC

2. WHAT IS RABIES-:
Rabies is a viral disease that causes acute encephalalitis (inflammation of the brain) in warm blooded
animals.
Rabies is endemic in india ,a vast country with a population exceeding 1.02 billion &a land area of3.2
million km.
Rabiess infects domestic&wild animals & is spread to people through close contact withinfected saliva
(via bites or scratches).
Once the symptoms of the disease develop,rabies is fatal.

3. HISTROY OF RABIES
➢Man described the disease in 2300 B.C.
➢The word “Rabies” originated from “rabhas” meaning “to do violence “.It described in ancient
Indian Sanskrit dating 3000B.C.
➢Since Roman times,manestablished the link between the infectivity of a rabid dogs saliva & the
spread of the disease.
➢Since there is no cure,they generally committed suicide to avoid painful death.

4. THINGS YOU SHOULD KNOW---
❖Mad Dog biting humans lead to Rabies.
❖Hydrophobia fear of Water,Saliva of Rabid Dogs
❖PASTURE’S SUCESSS-Vaccination

6. RABIES- A ZOONOTIC DISEASE
➢Etiology-;
Genus-Lyssavirus ,Family-Rhabdoviridae
➢ Most susceptible animals-Carnivors likeDog ,fox ,wolf& jackals
➢Highly susceptible animals- Wildcat, shunk ,mongoose
➢Moderately susceptible animals- Cattle ,goat, sheep , eqiuine
➢Dead end host- Cattle& equine
➢Rabies free countries- Australia,Japan,NewZealand ,Singapore , Great Britain ,Hong kong ,Antarctica

7. FIG -: Lyssavirus
As you can see ,these virionsare
bullet shaped & also enveloped.

8. MORE ABOUT LYSSAVIRUS--::
❖Rhabdovirus
❖Lyssavirus type 1
❖Bullet shaped virus
❖Size is 180*75 nm
❖Has a lipoprotein envelope
❖Knobs like spikes or glycoprotein G
❖Matrix protein layer
❖-Ve sense RNA ,linear ,unsegmented

9. HOST FACTORS

10. PATHOGENESIS----

11. RABIES IN DOGS

12. A RABID DOG
➢ FEVER
➢ DIFFICULTY IN SWALLOWING
➢ EXCESSIVE DROOLING
➢ STAGGERING
➢ SEIZURES
➢ PARALYSIS
➢ RESTLESSNESS
➢ INCREASED AGGRESION
➢ LOW ACTIVITY
➢ BITING
HOW TO KNOW YOR DOG HAS RABIES?

13. RABIES IN MAN--:
❑Known as hydrophobia (fear of water)
❑Duration of the disease-: 2-3 days prolonged to 5-6 day
❑Prodromal symptoms(3-4 days)is characterized by pain & numbness at the site of the bite
(Present in 50% -80% of cases) & nonspecific complaints such as fatigue ,headache & fever.
❑As the virus is neurotropic ,it results in exicitation & stimulationoff all parts of nervous system.
❑So the patient becomes intolerant to noise,brightlight,cold draught of air (sensory)
❑Aerophobia(fear of air) maybe present

14. ❑Increased reflexes& muscle spasms
❑Dialation of pupil & increased perspiration ,salivation,lacrimation.

15. ❑It followed by fear of death ,irritability ,anger & depression ( mental changes)
❑Patient dies abruptly due to convulsions or pass to coma & paralysis.

16. MORE ABOUT THIS DISEASE-
❑It has 2 forms.
1. FURIOUS FORM- It results due to irritationof the nerve cells induced by the virus
2. DUMBFORM- Which is also known as paralytic form results due to destruction of the
neurons
❑ Certain factors like the distance of bite fromCNS,degree of wound ,virulence&concentration
of virus or the host immune response play important role in pathogenesis.
❑The presence of hyalurodinase in the salivaof the biting animal particularly the wild
carnivores like wolvesincreases the permeability of the tissues & facilate the entry of the
virus.

17. GROSS PATHOLOGY-
❑As it’s the neurotropic virus,no specific gross regions are found.
❑In few cases post –mortem revealed severe congestion of meninges,cerebellum&cerebral
hemisphere with haemorrhage.
❑Edema of the cerebellum & cerebral hemisphere.In addition to,widening of the gyri&
narrowing of sulci of cerebral hemisphere were seen.

18. HISTOPATHOLOGY--::
❑Blood vessels of the brain are congested with perivascular lymphocytic infiltration.
❑Microglial cells proliferation & form small nodules -:”BABES NODULE”
❑Satellitosis around ganglion cells
❑Degeneration of ganglion cells – Neurophangis is seen in hippocampus
❑Acute catarrah of respiratory & digestive tract
❑ NEGRI BODIES- these are the intracytoplasmicinclusion bodies found in neurons
❑ In dogs –Hiippocamous impressionsmear
❑Cattle- Purkinje cells of cerebellumimpressionsmear

19. DEMONSTATIONOF NEGRIBODIES&PERI VASCULAR CUFFING:

20. THIS ARROW INDICATES NEGRIBODY

21. DIAGNOSIS--::
❑Histroy
❑Clinical signs
❑Demonstration of the negri bodies in brain impression smears
❑Histopathology-demonstration of negri bodies in Hippocampus of dog& Purkinje cells in the
cerebellumof the cow
❑FAT,ELISA for the demonstration of viral antigens
❑Isolation of the virus
❑Mouse inoculation Test

23. ❑Nursing personnel should be warned of risks & protect themselves with PPE
❑Persons with open wounds & cuts should not attend the patients
❑In places where rabbies are frequently encountered preexposure prohylaxis (2-3 doses of HDC
vaccine recommended)

24. HAPPY BIHU IN ADVANCE