RABIES
Dr. Ramakrishna HK
MS, DNB, FMAS.
Lakshmi Nursing Home
New Bridge Road
Bhadravathi
swarama@hotmail.com : 94486 67653
Dr. Ramakrishna HK
Rabies
Meaning
Sanskrit Word
RABHAS = VIOLENT
Dr. Ramakrishna HK
Rabies
The Virus
• A zoonotic disease
• Neurotrophic
• Rhabdovirus (bullet shaped virus)
Dr. Ramakrishna HK
Rabies
Introduction
• Only disease with 100% mortality
• Incidence maximum in India (36% of world)
• Causes of high mortality
Ignorance
Non availability of vaccine
Cost of treatment
Dr. Ramakrishna HK
Rabies
Dr. Ramakrishna HK
Rabies
Reservoir for Virus
• Dog: 90% cases
• Others: cat, other domestic animals
and wild animals
• Transmitted by bites and licks mainly
Person to person
Aerosol
Dr. Ramakrishna HK
Rabies
Dr. Ramakrishna HK
Rabies
Dr. Ramakrishna HK
Rabies
Dr. Ramakrishna HK
Rabies
At risk
• All worm blooded animals
• Persons working in laboratory with
rabies virus, veterinarians, dog
handlers, hunters, naturalists, forest
deportment workers etc…
Dr. Ramakrishna HK
Rabies
Pathogenesis
•
•
•
•
Virus multiplies near the bite site
Enters peripheral nerves
Ascends to CNS
Spreads centrifugally in peripheral
and autonomic nerves
• Involves the organs: Salivary gland,
myocardium, adrenal etc…
Dr. Ramakrishna HK
Rabies
Clinical Feature
• Incubation period: Long and variable
1 week to many years: Usually 3-8 weeks
• Depends on many factors
Site, severity, number of wounds,
amount of virus injected, species of
animal, clothing, treatment etc…
Dr. Ramakrishna HK
Rabies
Initial Symptoms
• Prodromal symptoms: Head ache,
malaise, sore throat, fever etc…
• Specific: Tingling or pain at the site of
bite
• Excitation & Stimulation: All parts of NS
Dr. Ramakrishna HK
Rabies
Later Phases
• Aerophobia
• Hydrophobia
• Intolerant to noise, light
• Violent spasms of pharyngeal and
neck muscles
Dr. Ramakrishna HK
Rabies
Examination
•
•
•
•
•
•
Increased reflexes
Dilatation of pupils
Increased perspiration
Increased salivation
Lacrimation
FEAR OF DEATH, anger, irritability
depression
Dr. Ramakrishna HK
Rabies
Duration of illness
• Usually 2 – 3 days
• May be prolonged 5 – 6 days
• Death: Convulsion or paralysis, coma
Dr. Ramakrishna HK
Rabies
Diagnosis
•
•
•
•
•
H/O animal bite
Pain at bite site
Hydrophobia
Aerophobia
Confirmation: Skin biopsy
(Immunoflorescence for antigen)
Virus isolation in saliva
Dr. Ramakrishna HK
Rabies
Treatment
• First Aid
• Active immunization
• Passive immunization
Dr. Ramakrishna HK
Rabies
WHO Recommendations
Dr. Ramakrishna HK
Rabies
Dr. Ramakrishna HK
Rabies
First Aid
• Wash: Copious amount of running water
• Mild soap
• Ethanol or iodine solution
• Avoid suturing: If must, infiltrate with RIG
Dr. Ramakrishna HK
Rabies
Active Immunization:
• VACCINE: Intra deltoid: Anterolateral thigh
• Nervous tissue based vaccines are no
more used
• Vaccine: Cell culture is the best
Dr. Ramakrishna HK
Rabies
WHO Schedule
• 0, 3, 7, 14, 28
• 90 optional
• Should not overlap antimalarial
treatment
• Serum antibody titre > 0.5 IU/ml
Dr. Ramakrishna HK
Rabies
Dr. Ramakrishna HK
Rabies
RABIES IMMUNOGLOBULINS
• Passive Immunization
• Neutralize virus on contact
• Gives a coating to the virus so that it
cannot enter the nerve ending
Dr. Ramakrishna HK
Rabies
TYPES
1. Human Rabies Immunoglobulin
(HRIG)
2. Equine Rabies Immunoglobulin
(ERIG)
Dr. Ramakrishna HK
Rabies
HUMAN RABIES IMMUNOGLOBULINS
• Immunoglobulins mainly IgG obtained
from plasma or serum of donors
immunized against rabies
• Plasma pooled from more than 1000
donors – previously immunized.
• Passive protection immediately
Dr. Ramakrishna HK
Rabies
HRIG: Advantages
1. Purity
2. Minimal or no foreign protein
3. Minimal risk of hypersensitivity
4. Negligible side effects
Dr. Ramakrishna HK
Rabies
HRIG : Disadvantages
• Expensive
• Risk of viral agents –
(HIV, Hepatitis-B, Hepatitis-C)
• Shortage because of low yield
Dr. Ramakrishna HK
Rabies
EQUINE RABIES IMMUNOGLOBULINS
• Immunizing horses with rabies
vaccines
• Serum processed by modern
automated ultra filtration technology
• Contains purified antibodies against
Rabies
Dr. Ramakrishna HK
Rabies
ERIG: Advantages
1.
2.
3.
4.
Massive Yield
Low cost
Widely available
Modern purification and ultra
filtration technologies has made it
safer.
Dr. Ramakrishna HK
Rabies
ERIG: Disadvantages
Presence of foreign protein
Risk of immediate hypersensitivity
Dr. Ramakrishna HK
Rabies
INDICATIONS FOR RIG
1. Category III bites (WHO classification)
2. Licks on mucous membranes by wild
or pet animals
3. AIDS : Category II & III bites
4. Varicella (Chicken pox)
Dr. Ramakrishna HK
Rabies
INDICATIONS FOR RIG
Cont’d
5. Long term Corticosteroids
6. Long term Chemotherapy
7. Radiation Therapy
8. Wound suturing (pre-infiltration)
Dr. Ramakrishna HK
Rabies
Dosage
1. Human Rabies Immunoglobulin
20 Units per kg of body weight
2. Equine Rabies Immunoglobulin
40 Units per kg of body weight
3. Maximum dosage: HRIG 2000 IU
ERIG 4000 IU
Dr. Ramakrishna HK
Rabies
Administration
• Infiltrated into and around the wound.
• The remaining portion if any, to be
injected in to the opposite deltoid
Dr. Ramakrishna HK
Rabies
• Partially suppresses active production
of rabies antibody.
• Only once: Not beyond the 7th day of
bite
Dr. Ramakrishna HK
Rabies
Administration: Precautions
• Warm before intramuscular injection.
• Site & syringe – different from ARV.
• Avoid RIG seeping out of wounds. If so,
the volume should be estimated and
replaced.
• Caution is needed if injecting into a
tissue e.g. finger pulp, excess fluid can
result in increased compartmental
pressure and lead to necrosis.
Dr. Ramakrishna HK
Rabies
RIG TREATMENT - CHILDREN
• The same calculated dosage
• If insufficient to infiltrate all
wounds, dilute with sterile NS 2 to 3
fold
• Total dose of RIG should not be
increased
Dr. Ramakrishna HK
Rabies
RIG
• Provides
immediate
passive
antibodies
• Protects the patient until the patient
can produce own antibodies from the
rabies vaccine.
• Adequate titre of passive antibody is
present
24
hours
after
RIG
administration.
Dr. Ramakrishna HK
Rabies
Duration of Protective Effect:
Short
Half-life: Approximately 21 days.
Dr. Ramakrishna HK
Rabies
Cross sensitivity
Patients sensitive to other human
immune globulin products may be
sensitive to Rabies Immunoglobulin
also.
Dr. Ramakrishna HK
Rabies
SIDE / ADVERSE EFFECTS
• Rare.
• Local: Pain, tenderness at injection
site
• Systemic: Headache, Fever, Chills,
Flushing, Backache, Nausea
• Sensitization and subsequent reaction
to IgA containing material, such as
blood and plasma
Dr. Ramakrishna HK
Rabies
Drug Inter actions
• Can impair the efficacy of live attenuated virus
vaccines such as Measles, Mumps, Rubella and
Varicella (for a period of at least 6 weeks and up
to 3 months).
• Vaccines should be administered 14 days prior to
or 3 months after administration of RIG.
• Over dosage: Significant depression of active
immunity.
• Avoid repeated doses: prevents full development
of the active immunity expected from the
vaccine.
Dr. Ramakrishna HK
Rabies
Intradermal Test
• Intradermal test: mandatory
• Test: 0.1 ml of RIG: intradermally on
the left forearm.
• Observation: observed for 30 minutes
for local: 24 hours for systemic
reactions
Dr. Ramakrishna HK
Rabies
Reactions
• Local: Erythema, Wheal, Severe pain at
the local site.
• Systemic: Giddiness, mild circulatory
collapse with fall of BP.
• Precaution: Keep Resuscitation set ready
History of sensitization to
other vaccines or immunoglobulins, give
anti- histamines prior to administration.
Dr. Ramakrishna HK
Rabies
Management
Mild Local Reaction: Anti histamines
Systemic
reaction:
Adrenaline
1:1000
(Aqueous) – 0.01ml/Kg/ dose repeated
every 10 – 20 minutes.
• Usual Doses:
Infants – 0.05ml – 1ml
Children – 0.1 0.3 ml
Adolescents – 0.3 – 0.5 ml
Dr. Ramakrishna HK
Rabies
Management: Cont’d
SEVERE CASES:
HYDROCORTISONE : I.V 100 – 200 Mg
Dr. Ramakrishna HK
Rabies
CHILDREN, PREGNANCY AND
LACTATION
Dr. Ramakrishna HK
Rabies
Previously Immunized
• Do not use RIG
• Active immunization: 0, 3, 7.
• If antibody titre > 0.5 IU/ml 0, 3.
Dr. Ramakrishna HK
Rabies
Additional treatment
Dr. Ramakrishna HK
Rabies
Observation of dog & cat
• If dog is alive at 14 days
Dr. Ramakrishna HK
Rabies
Storage
• Vaccine and RIG
• At 2-8*C
• Not in Freezer
Dr. Ramakrishna HK
Rabies
Animal bite: Exceptions
• Rodents
• Rabbit
Dr. Ramakrishna HK
Rabies
Prevention
• Vaccine: 0, 7, 28 (Or 21).
• Maintain continued immune status by
boosters at 1 yr and every 2-3 yrs
• For at risk group
Dr. Ramakrishna HK
Rabies
Thank You
Dr. Ramakrishna HK
Rabies