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RABIES Primarily a Zoonotic disease of warm
blooded animal such as :- Dogs, wild cats, Jackals, wolves etc.
It is caused by the Neurotropic RNA virus belongs to Rhabdoviridae type I (LYSSAVIRUS type I) is Bullet shaped virus
It is an acute Highly fatal viral dis: of CNS
Transmitted to man by: Bites
OR Licks of rabid animals
Rabies virus structure
EnvelopeMatrix protein
Source: http://www.cdc.gov
Glycoprotein
Nucleocapsid protein
History of Rabies Virus
Man described the disease in 2300 B.C.
The origin “rabhas”, meaning “to do violence” comes from ancient Indian Sanskrit dating 3000 B.C.
History of the Rabies VirusSince Roman times, man established the link between the infectivity of a rabid dogs saliva and the spread of the disease.
Because there is no cure for rabies, those that had been bitten by a rabid dog would commonly commit suicide to avoid the painful death that would inevitably follow.
History of the Rabies Virus Louis Pasteur was the first person to
diagnose that rabies targeted the CNS. Also determined that nervous tissue of an
infected human or animal also contained the virus.
In 1890 created the rabies vaccine and saved 9 year old child after he had been bit by a rabid dog.
Epidemiology87 countries contain Rabies, but more
cases are reported in Asia.In Indo-Pakistan rabies is a major
public health problem mainly due to presence of a large no: of stray dogs.
More than 30,000 people died of Rabies every year in Asia. Every year 10 million people require treatment and protection from Rabies which is great Financial loss.
RESERVOIR OF INFECTION
1) URBAN RABIES:
From Dogs and cats.
2) WILD LIFE RABIES: From jackals and foxes.
3) BAT RABIES: Vampire bats which live on the blood of animals and men.
These are one of the main causes of the death of bovine, around 0.5 to 1 million per year.
Source of Infection
Saliva of Rabid animal
Host Factors
All warm blooded animals including man.
Rabies in man is a dead-end infection.
Mode of Transmission
1. ANIMAL BITES
2. LICKS
3. AEROSOL
4. PERSON TO PERSON
INCUBATION PERIOD:
normally it is 3 - 8 wks
may be short that is 4 days
or may be prolonged for years.
CLINICAL PICTURE1. Prodromal symptoms
Headache, malaise, sore throat, low fever, pain at the site of bite
2. Excitation Symptoms sensory sys: involvement Aero phobia, excitation of N.S. Motor sys: inv: increase reflexes, muscle spasm,
Symp:inv: dilatation of Pupils. increase perspiration, salivation, and Lacrimation,
Mental changes: fear of death, anger, irritability and depression
Hydrophobia ( Fear of water)
sight or sound of water may produce spasm of degulation
the duration of illness is 2-3 days may be prolonged to 5-6 days
Stage of paralysis & coma
DEATH / Recovery
Clinical forms of rabies
encephalitic = furious ~ 80%
paralytic = dumb ~ 20%
Encephalitic rabies prodromal symptoms paresthesias/pain/pruritus at site of bite episodes of generalized arousal or
hyperexcitability separated by lucid periods
autonomic dysfunction hydrophobia
Paralytic rabies paresthesias/pain/pruritus at site of bite early flaccid muscle weakness
often begins in bitten extremity progresses to produce quadriparesis bilateral facial weakness
sensory examination is usually normal sphincter involvement fatal outcome often misdiagnosed as Guillain - Barré syndrome
DIAGNOSIS
1. History
2. Sign and symptom
3. Examination
4. Detection of Antigen by taking Skin Biopsy using Immunofluorescence
by virus isolation from Saliva & other secretions.
Control Measures Notification Isolation Disinfection Immunization
Prevention of human rabiespost Exposure prophylaxis
1. General consideration:- Aim is to neutralize virus before entering CNS
2. LOCAL WOUND TREATMENT a, Cleansing of wound(soap & water) b, Chemical treatment: Either Alcohol 400-700 ml /liter Tincture Iodine
c, Suturing not recommended
d, Anti Rabies Serum
e, Antibiotic and ATS
f, Observe the animal for 10 days
3, Immunization 1,NERVOUS TISSUE VACCINE (NTV
2, Human diploid cell vaccine (HDCV)
Evaluation of Animal Recommendation
Healthy and available for 10 days observation
No treatment unless animal develops clinical signs of rabies
Rabid or suspected rabid Immediate treatment*
Unknown (e.g., escaped) Consult local public health department
*Discontinue treatment if tests on animal prove negative.
Rabies postexposure guide: exposure to dogs, cats, and ferrets
Vaccines for immunizationDefinition:
it is fluid or dried preparation of Rabies “Fixed” virus grown in the Neural tissue of
Rabbits, Sheep, Goats, Mice or Rats OR in embryonated duck eggs OR in cell culture
Nervous Tissue vaccine
Duck embryo vaccine
Cell culture vaccine
preparation From fixed virus grown in brain of sheep or other animals
potency Low or variable Eliminate Neuroparalytic factors
More potent
more safer
Doses Large nos: are required Fewer doses of small volume
Side effects Severe & fatal reactions Allergic risks Fewer
Uses Exposed subjects Used in UK,USA in past 1, (HDC) safe, potent Pre & post expos:Immunization
Suckling mouse brain V Devoid of Neuroparalytic effect
Used in Latin America Improvement over adult animal nervous tissue V
Now purified DEV developed
Improvement over adult animal nervous tissue V
Not available in India & Pakistan
2Tissue culture 2nd G (Non-human)
Potent, low cost
WHO recommendatio
Type of VaccineNERVOUS TISSUE VACCINE (NTV)
a. Derived from adult animal nervous tissue eg. Sheep
b. Derived from suckling mouse brainType: Killed viral vaccineDose: 2.5 ml S/C (Ant. Abdominal wall)Schedule: 14 doses
Type of Vaccine (conti)Duck Embryo Vaccine (DEV)
Type: Killed viral vaccine
Dose: 1 ml S/C ( Ant. Abdominal wall)
Schedule: 14 doses OD
not available in Pakistan
Type of Vaccine (conti)CELL CULTURE VACCINES
a. Human diploid cell vaccine (HDCV)b. Second generation tissue culture vaccine
(non- Human)Type: Killed viral vaccineDose: 1 ml IM Schedule: on 0, 3, 7, 14, 28 day,
booster on day 90
Adverse Reactions to Rabies Vaccines
Most common side-effects of rabies vaccines:
Systemic reactions such as headache, myalgia, malaise (5-40%)
Mild to moderate local reactions at injection site (30-74%)
PASSIVE IMMUNIZATION Horse Anti Rabies serum: 40 iu / kg at
0 day Human rabies immunoglobin (HRIG):
20 iu / kg around the wound and rest in IM on 0 day
Booster doses are essential whenever anti rabies serum is given with the vaccine
IMMUNITY Duration of Immunity is upto 06 month If again bite by rapid animal than dose
according to blood titre
if more than 0.5 i.u. / ml than only two dose 0, 3 day
if less than 0.5 i.u. / ml than 0, 3, 7 day
General measures Regist:,licensing & taxation of dog. Muzzling of dogs Yearly mass vaccination of dog Destruction of stray dogs Facilities for diagnosis of rabies in dogs Destruction of wildlife where the animals are
known to be the reservoir of infection. Publicity
Preexposure rabies prophylaxis
3 doses of rabies vaccine (days 0, 7, and 21 or 28)
May check rabies antibody titre periodically – want >0.5 IU/mL
after a rabies exposure:
2 doses of IM rabies vaccine (days 0 and 3)
no HRIG
Day 0 7 21 28
Pre-exposure rabies prophylaxis
Tissue culture vaccine: 1 dose IM or 0.1 ml ID
Rabies prevention - Summary Rabies is a preventable disease. Failure to recognize a risk of infection results in
human deaths. Increased awareness of sources and routes of
virus transmission could save lives. Pre-exposure vaccination should be used widely. Post-exposure treatment is urgent. For previously vaccinated people post -exposure
treatment is simpler, cheaper and more effective.