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1. RHABDOVIRUS
Rabies
NAME: Yusuf Yusuf o
GROUP: 31

2. Introduction
Rabies(from Latin:rabies, “madness”) is viral
disease caused by encephalitis in warm
blooded animals.It is zoonotic, most
commonly by a bite of infected animal.The
rabies virus infects the central nervous system
, ultimately causing disease in the brain and
death.

3. Classification
• Order: Mononegavirales
• Family: Rhabdoviridae
• Genus: Lyssavirus
• Species: Rabies virus

5. Rhabdoviruses
• Features
• Bullet-shaped (75 x 180 nm)
• Enveloped
• Single stranded RNA genome, 12 kb
• Many viruses with broad host ranges
• Several structural proteins are present
in nucleocaspid
• Virus is coated by outer lipoprotein
envelope carrying spikes.

6. • Animal susceptibility
• All warm-blooded animals can be infected with varying susceptibility
• High - wolves, coyotes, foxes, dogs
• Intermediate - skunks, raccoons, bats
• Low - opossums
• Virus occurs in saliva, nervous system, urine, lymph, milk
• Recovery is rare and only occurs in bats; fatal in nearly all others
• Vampire bats can transmit virus for months
Rabies Virus

7. • Epidemiology
• Enzootic in wild and domesticated animals
• In the U.S., edible vaccines are dispersed to control wild animal rabies
• More than 200 people die from rabies in China each month
• Reservoirs might be bats
• But the slow-growing nature of rabies virus also contributes to its persistence in
nature
Rabies Virus

8. Resistance
• The virus is sensitiv to ethanol, iondine
preparation, lipid solvents such as ether
chloroform and acetone.It is inactivated by
phenol, formalin, UV irradiation and sem
light.
• Thermal inactivation occurs in 1 hour at
50°C and 5 min at 60°C.It dies at room
temp. but can survive for weeks when
stabilized by 50% glycerol.

9. Antigenic Properties
• The surface spike is composed of
glycoprotein 6, which induces the
formation of protective antibodies when
injected into animals.
• Rabies virus possesses hemoglutinating
activity optimally seen with goose
erythrocytes at 0-4°C and pH
6.2.Hemagglutination is property of the
glycoprotien spikes.The hemagglutinin
antigenic is species specific.

10. • The nucleocapsid protein induces
complement fixing antibodies.These are not
protective.This antigen is group specific and
cross reactions is seen with some rabies
related viruses.

11. Host range and growth
characteristics
• All warm blooded animals are susceptible
to rabies infection though in exist
susceptibility differences between the
species.Cattle,cats and foxes are highly
susceptible.Whereas skunks and fowl are
relatively resistance.
• Human being and dogs occupy intermediate
position.Puppies are more susceptible than
adult dogs.

12. • The rabies virus isolated from natural human or
animal infection is termed the street virus.
• Following inoculations by any route it can cause
fatal encephalitis in laboratory animals after a
long and variable incubation period(1-2 weeks)
• After several serial intracerebral passages in
rabies,the rabies undergoes several changes and
becomes fixed virus.The fixed virus is more
nurotropic and it is much less infective.
• Fixed virus is used for vaccine production.

13. Chicken embryos
• The rabies virus can grow in chicken
embryo.The usual mode of inoculation is
into yolk sac. They can also grow in
fibroblast, hamates kidney.

14. Rabies Virus
• Pathogenesis
• Requires several weeks for infection to become apparent
• Transmission through bite or scratch from infected animal
• Replication in muscle and connective tissues at site of inoculation
• Enters peripheral nervous system at neuromuscular junctions
• Spreads up the peripheral nerves to the central nervous system
• Encephalitis
• Virus grows to high titers in the salivary glands
• Rabies patients must be restrained
• Negri bodies appear in neuron cell bodies
• Clinical spectrum
• Prodrome - nausea, headaches, fever, sore throat,
photophobia
• Acute neurologic phase - apprehension, nervousness,
hallucinations, behavioral anomalies, salivation, perspiration,
hydrophobia, photophobia
• Coma - seizures and death (99+%)
Negri bodies

15. PATHOGENESISPATHOGENESIS
Live virusLive virus Epidermis, Mucus membraneEpidermis, Mucus membrane
Peripheral nervePeripheral nerve
CNS ( gray matter )CNS ( gray matter )
Other tissue (salivary glands,…)Other tissue (salivary glands,…)
centripettally
centrifugally

17. Laboratory diagnosis
• Demonstration of rabies virus antigenis
structure by immunofluorescence.The
specimens tested are corneal smear and
facial skin biopsy antemortem and brain
postemortem.Virus also may be detected
by virological method.

18. Rabies Virus
• Laboratory diagnosis
• PCR
• Serology (IFA)
• Animal control
• Rabid or suspected rabid animals are killed and examined by
histopathology for Negri bodies and viral antigen
• Vaccination of pets is required by law in most states
• Immunity and protection
• Vaccines
• First one developed by Pasteur by using spinal cords from infected dogs
• Today’s principal vaccine is the human diploid cell vaccine (HDCV) made in the WI-
38 fibroblast cell line
• Virus is inactivated by PLβ
• Post-exposure prophylaxis
• One dose of hyperimmune antiserum
• Five immunizations over 28 days

19. Prophylaxis
• Specific prophylaxis is ideally given before
exposure to infection.In animals this is
imperative but in human beings pre-exposure
immunization was only employed in persons at
high risk,such as veterinarians and dog handlers.
• Specific prophylaxis is generally employed after
exposure to infection and is called
treatment.This consist of local
treatment,antirabii vaccine and hyperimmune
serum.

20. Local treatment
• Cauterization of wound.
• The wound should be immediately washed
well with soap and water.
• Wounds treated with ammonium
compounds,iodine tincture,alcohol(40-70%)
• Antibiotics to prevent serum.

21. Vaccination
1.Neural vaccines
These vaccines consist of nervous tissues of animals
infected with the fixed rabies virus.
2.Nonneural vaccines
Egg vaccines,duck egg vaccine containes fixed adapted
for growth in duck eggs and innactivated by beta-
propolactone.This vaccine is pure immunogenic.

22. Thank You