Rhabdoviruses are a family of viruses that contain negative-stranded RNA and infect vertebrates including humans. They are transmitted primarily through animal bites. The most common rhabdovirus that infects humans is the rabies virus. Rabies virus causes an acute viral infection of the central nervous system that is nearly always fatal if post-exposure prophylaxis is not administered.

1. RHABDO VIRUS

2. RHABDO VIRUS
Prepared by: Presentation with:
SAgun PAudel o Samjhana gurung
Health Assistant
o Sabita timilshina
Student of BPH @ LA
GRANDEE International o Sarala kumal
college, Simalchour
o Samjhana gurung
Pokhara, Nepal

3. INTRODUCTION:
The name is derived from the Greek “rhabdos’’
meaning rod referring to the shape of the viral
particles.
They contain a negative stranded RNA genome
and are very stable to drying.
This group of viruses has a broad host range but
there is only one that affects humans. The viruses
are generally introduced through a bite wound.

4. CHARACTERISTICS:
 Rhabdoviruses carry their genetic material in the
form of negative-sense single-stranded RNA.
They typically carry genes for five proteins:
 large protein (L)
 glycoprotein (G)
nucleoprotein (N)
phosphoprotein (P) and
matrix protein (M).
 Rhabdoviruses that infect vertebrates are bullet-
shaped.

5. CHARACTERISTICS :
 Animal rhabdo viruses infect insects, fish, and
mammals, including humans.
 Present in saliva and transmitted by animal bite.
 The most common virus of this family is rabies virus.

6. CLASSIFICATION:
 Group: Group V (-)ssRNA
 Order: Mononegavirales
 Family: Rhabdoviridae
 Genera:
 Vesiculovirus
 Lyssavirus
 Nucleorhabdovirus
 Nucleorhabdovirus
 Novirhabdovirus

7. MORPHOLOGY:

8. MORPHOLOGY
Electron
micrograph of
the rhabdovirus
at 64,000X
magnification:
Notice the bullet-
shaped virions
surrounding the
cell. The dark
circle in the cell
is the Negri
body:

9. MORPHOLOGY:
o The most outstanding characteristic of the
rhabdovirus is the bullet-shaped virion.
o Such a shape is caused by a lipid
envelope, embedded with glycoprotein
peplomers, surrounding a helically wound
nucleocapsid.
o The virions tend to be approximately 70 nm
wide and 170 nm long.
oMatrix proteins can also be found
under the lipoprotein envelope.

10. REPLICATION:
 Replication of many rhabdoviruses occurs in the
cytoplasm, although several of the plant infecting
viruses replicate in the nucleus.
 In order for replication, both the L and P protein
must be expressed to regulate transcription.
Transcription results in five monocistronic mRNAs
being produced because the intergenic sequences
act as both termination and promoter sequences for
adjacent genes

11. REPLICATION:
 During their synthesis the mRNAs are processed to
introduce a 5' cap and a 3’ polyadenylated tail to each of the
molecules.
 This structure is homologous to cellular mRNAs and can
thus be translated by cellular ribosomes to produce both
structural and non-structural proteins.
Genomic replication requires a source of newly
synthesized N protein to encapsidate the RNA.
This occurs during its synthesis and results in the
production of a full length anti-genomic copy.


12. REPLICATION:
 This in turn is used to produce more negative-
sense genomic RNA.
 Replication characteristically occurs in an
inclusion body within the cytoplasm, from where
they bud through various cytoplasmic
membranes and the outer membrane of the cell.
 This process results in the acquisition of the M +
G proteins, responsible for the characteristic
bullet- shaped morphology of the virus.

13. PATHOGENESIS:
 Rhabdoviruses generally enter via a bite or a
wound infected with saliva.
 Initially, the virus replicates at the site and then
infects CNS tissue.
Incubation period:
 6 days up to 1 year
 average 30-70 days.
 virus spreads rapidly via the nerves. CNS damage
produces the symptoms of disease.
 Neurons accumulate ribonucleoprotein as
intracytoplasmic inclusions. Infection of the
thalamus, hypothalamus or pons may occur.

14. CLINICAL PRESENTATION:
Most cases go through three stages. [classical
rabies]:
I. Prodromal Stage :
lasts from 2-10 days and presents in the form of
fever, headache, malaise, fatigue, and also
localized pain around area of initial
infection.
I. Sensory Excitation:
hyperactivity, hallucinations, disorientation, seizur
es and bizarre behavior.

15. CLINICAL PRESENTATION:
Also about 50% of infected individuals developed
painful spasms of the pharynx and larynx resulting
in a fear to eat or drink. Because of this fear they
drool rather than swallow.
Increased salivation is another symptom of the
disease, thus adding to the drooling problem.
This phase persists for 2-7 days.
III. Coma and Paralysis Phase:
as the disease persists deterioration of CNS tissue
leads to
paralysis and respiratory problems.

16. CLINICAL PRESENTATION:
About 20% of cases have only two phases [dump
rabies]:
patient skips the sensory excitation phase and
progresses right to the coma and paralysis phase.
Dumb rabies is almost 100% fatal with only three
known cases of survival.
In each of these cases the patients had high titers of
antibody in the CSF.

17. LABORATORY DIAGNOSIS:
 Diagnosis is perform best by FA staining or RT-PCR
of infected cells or tissues.
 Animals are diagnosed through histological
examination of the CNS for Negri bodies.
 The cytoplasmic Negri body is a diagnostic of rabies
encephalitis. size (7 micrometers) and color as a
mature RBC.
 brain biopsy.
 Indirect immunofluorescence is most often used to
detect rabies antigen [impression smear, oronasal
mucosa scrapings, or hair follicles of the neck].

18. A CYTOPLASMIC NEGRI BODY:

19. CONTROL
Sanitary : cleansing of a bite wound to reduce the
number of viral particles can help to prevent disease.
Use of the vaccine for all dogs (a modified live
vaccine) and cats (a dead virus suspension) is
important in preventing spread to humans.
Immunological : Both active and passive
vaccination may be used to prevent human disease.
The active vaccines are inactivated virus grown in
human diploid cell cultures (HDCV) while the passive
vaccine uses immunoglobulin.
There is no any chemotherapeutical control
available.

20. TREATMENT:
 Immediate First Aid :
The virus remains localized at the site of the wound for a
period of time. To help recovery, wash the wound with
soap and water as soon as possible, and follow with
application of an antiseptic.
 Vaccine :
 Human Diploid Cell Vaccine :
HDCV should be given intramuscularly on days
0, 3, 7, 14, and 28, followed by a booster dose on day 90.
 nervous tissue vaccine, or duck embryo vaccine.
 Human Rabies Immune Globulin.

21. PREVENTION:
 Rabies is the only human disease that can be
prevented by active immunization after infection. This
is possible due to the long
incubation period of the virus.
 Pre-Exposure Immunization:
Anyone at high risk of contact with rabid animals may
seek pre-exposure prophylaxis.