BRIEF ABOUT RABIES VIRUS

1. CLASSIFICATION-
FAMILY = RHABDOVIRIDAR
GENERA= VESICULOVIRUS

2. MORPHOLOGY
 BULLET SHAPED
 ENVELOPED-LIPID ENVELOPED
 - PEPLOMERS OR
SPIKES(GLYCOPROTEIN G)
 INTERNALLY LINED BY MATRIX PROTEIN
 NUCLOCAPSID=HELICAL SYMMETRY,(-
)SENSE ssRNA,RNA ,NUCLEOPROTEIN
AND POLYMERASE PROTEIN

3. DIAGRAM

4. ANTIGENIC PROPERTIES
 MAJOR FACTOR IS “GLYCOPROTEIN-G”
RESPONSIBLE FOR ITS NEUROINVASIVENESS AND
PATHOGENICITY

5. ANIMAL SUSCEPTIBILITY
 INFECT ALL WARM BLOODED ANIMALS
INCLUDING HUMANS.
 SUSCEPTIBLE ANIMALS ARE MAINLY Dogs, Cattles,
Sheep, Goats, Bats, cats, foxes Cotton Rats

6. Changes on propagation in animals
 STREET VIRUSES: these are freshly isolated strains from lab.
 *mimic wild viruses
 *long and variable incubation period
 Produce INTRACYTOPLASMIC inclusion bodies( NEGRI bodies)
 FIXED VIRUSES: are street viruses propagated in rabbit by brain to
brain passage loose certain properties and become fixed
 *don’t produce inclusion bodies
 *don’t multiply in extraneural tissue
 *don’t infect salivary gland
 *multiply rapidly in 4-6 days
 Used for vaccination

7. PATHOGENESIS
 TRANSMISSION:
 TO HUMANS MAINLY BY BITE OF INFECTED
ANIMAL
 DOG BITE IS MOST COMMON
 BAT BITE MOSTLY GOES UNNOTICED
 LINK ON ABRASION OR MUCOSA
 INHALATION OF INFECTED AEROSOLS OF BATS
 CORNEA TRANSPLANTATION

8. SPREAD OF VIRUS
 MULTIPLY LOCALLY: AT SITE OF INOCULATION
IN MUSCLE OR CONNECTIVE TISSUE
 VIRAL ENTRY TO PERIPHERAL NEURONS: VIRUS
BINDS TO NICOTONIC ACETYLCHOLINE
RECEPTOR AT NEUROMUSCULAR JUNCTION
 NEURONAL SPREAD: CENTEPRATELLY ALONG
MOTOR NERVES VIA RETROGRADE FAST AXON
TRANSPORT
 CNS INFECTION: MOSTLY MENTAL SYSTEM SUCH
AS HIPPOCAMPUS AND CEREBELLUM

9. SPREAD OF VIRUS
 CENTRIFUGAL SPREAD: FROM CNS THROUGH
SENSORY AND AUTONOMIC NERVES TO TISSUES
AS SALIVARY GLANDS TO PANCREAS ,KIDNEY
,HEART, RETINA AND CORNEA
 VIREMIA DOESN'T OCCUR
 SHED IN SALIVA

10. PATHOGENESIS OF RABIES

11. CLINICAL MANIFESTATIONS
 INCUBATION PERIOD
 20-90 DAYS (CAN BE 1 WEEK -19 YEARS)
 INVERSELY RELATED TO DISTANCE FOR VIRUS TO
TRAVEL FROM SITE OF INCUBATION ;HENCE
SHORTER IN
 CHILDRENS,SHORT PEOPLE, BITES ON HEAD,
NECK AND UPPER LIMBS, LOW HOST IMMUNITY

12. CLINICAL SPECTRUM OF RABIES
 1) SHORT PRODOMINAL PHASE:
 LASTS FOR 2-10 DAYS
 CHARACTERIZED BY NON SPECIFIC SYMPTOMS
 FEVER,PHOTOPHOBIA,SORETHROAT,ABNORMSL
SENSATION AROUNMD WOUND, NAUSEA

13.  2)ACUTE NEUROLOGICAL PHASE:
 *ENCEPHALITIC RABIES. SYMPTOMS ARE
.HYPEREXCITABILITY
ANXIETY,HYPERACTIVITY,AGITATION,BIZARRE
BEHAVIOUR
 HYPEREXCITABILITY IS FOLLOWED BY LUCID
INTERVAL
 AUTONOMIC (SYMPATHETIC)
DYSFUNCTION:↑SALIVATION,↑LACRIMATION
↑PERSPIRATION,CARDIAC ARRHYTHMIA
 PARALYTIC OR DUMB RABIES: IN PARTIALLY
VACCINATED AND BAT RABIES INFECTED PEOPLE
 CHARACTERIZED BY FLACCID PARALYSIS USUALLY
FROM BITTEN LIMB

14.  3) COMA AND DEATH
 PATIENT DEVELOPS COMA LEADING DEATH
AFTER ACUTE NEUROLOGICAL PHASE
 DEATH OCCOURS IN 14 DAYS SOMETIMES IN 30
DAYS

15. LAB DIAGNOSIS
 ANTIGEN DETECTION -BY IF
 VIRAL ISOLATION-MOUSE AND CELL LINE
INOCULATION
 ANTIBODY DETECTION FROM SERUM AND CSF-BY
MNT,RFT-IT,FAVN,IFA,HAI AND CFT.
 VIRAL RNA DETECTION BY-RT-PCR
 NEGRI BODY DETECTION IN
HISTOPATHOLOGICAL STAINING OF BRAIN
BIOPESIS

16. FULL FORMS OF TESTS
 MOUSE NEUTRALIZATION TEST (MNT)
 RAPID FLUORESCENT FOCUS INHIBITION TEST
(RFFIT)
 FLUORESCENT Ab VIRUS NEUTRALIZATION
TEST (FAVN)
 INDIRECT FLUORESCENCE ASSAY (IFA)
 HEMAGGLUTINATION YTEST (HAI)
 COMPLEMENT FIXATION TEST (CFT)

17. NEGRI BODIES DETECTION
 USEFUL FOR POSTMORTEM DIAGNOSIS OF
RABIES
 IT IS AN INTRACYTOPLASMIC EOSINOPHILIC
INCULSIONS WITH CHARACTERISTIC
BASOPHILIC GRANULES
 SPHERICAL OR OVAL IN SHAPE

18. THANK YOU
PREPARED BY: ANSAR
AHMAD PARAY
Bsc.MLT