Rabies vaccine dose in Nepal 2080- How to give rabies vaccine
Introduction
Rabies is a disease with the highest documented case-fatality rate, close to
100%.
Rabies is a vaccine-preventable viral zoonotic disease responsible for an
estimated 59,000 human deaths every year.
Dogs are responsible for up to 99% of human rabies cases in rabies-endemic
regions like Nepal.
Many human rabies cases are not admitted, or patients leave against medical
advice (LAMA) due to no documented good outcome.
There are a couple dozen cases of rabies survivors which died after few months
or years and had very bad neurological sequale due to rabies.
The Rabies Virus (RABV) belongs to the genus Lyssavirus in the family
Rhabdoviridae and order Mononegavirales.
All Lyssavirus eselicit an acute progressive encephalitis in human
beings.
There are at least 14 individual Lyssavirus species, subdivided into 2
phylogroups based on genetic distance and serological cross-reactivity.
RABV is an unsegmented, single-stranded, negative-sense, enveloped RNA virus
and belongs to Phylogroup 1.
The genome encodes fi ve proteins; the most important of these from an
immunization perspective is the G glycoprotein, which includes the antigenic
sites targeted by rabies vaccines and passive immunization.
Types of rabies:
- Furious form (classsical )
- Paralytical form
Consequence of an exposure to RABV (Rabies virus) depends on these factors:
- The severity of the wound
- The location of the bite on the body
- The quantity of virus inoculated into the wound(s), and
- The timeliness of post-exposure prophylaxis (PEP)
Without PEP, the average probability of developing rabies following a
bite by a rabid animal to the head is 55%, upper extremity 22%, the
trunk 9% and a lower limb 12%.
Signs and Symptoms of Rabies
Initial Symptoms
- Pain or paraesthesia at the wound site
- Fever
Later Symptoms
- Hyperactivity
- Fluctuating consciousness
- Hallucinations
- Hydrophobia (furious rabies)
- Paralysis and coma (paralytic rabies)
- Followed by death
RABV infection in rodents is very uncommon. No human rabies cases due to
bites by rodents have been reported. Exposure to domestic rodents,
squirrel, hare and rabbits do not routinely require PEP.
The clinical presentation of the two types of rabies:
Furious Rabies (Classical)
- Hydrophobia
- Aerophobia and Photophobia
- Excitation and confusion
- Excessive sweating and salivation
- Dehydration
- Death in 2-5 days
Paralytic Rabies
- Gradual ascending paralysis
- Hydrophobia is not seen
- Myoedema and piloerection
- Stupor, Coma
- May resemble Guillain–Barré syndrome
- Death in 1-2 weeks
With the exception of hydrophobia, clinical signs of rabies can be
unreliable.
Differential Diagnosis of Rabies
- Cerebral malaria
- Organophosphate poisoning
- Herpes simplex encephalitis
- Post-vaccinal encephalitis
- Scorpion and snake envenomation
- Illicit drug use
- Psychiatric disorders
Post Exposure Prophylaxis (PEP)
Rabies in humans can be prevented, after exposure, by PEP.
Proper wound management combined with prompt post-exposure use of Cell
Culture Vaccines and Embryonated Egg-based Vaccines (CCEEVs) and
simultaneous administration of RIG in severe exposures, is close to 100%
effective in preventing rabies.
WHO Classifi cation of Exposures
Category I
Touching or feeding of animals, Animal licks on intact skin (NO EXPOSURE)
Category II
Nibbling of uncovered skin, Minor scratches or abrasions without
bleeding (EXPOSURE)
Category III
- Single or multiple trans dermal bites or scratches
-
Contamination of mucous membrane or broken skin with saliva from animal
licks
- Exposures due to direct contact with bats
- Bite by all wild animals should be treated as Category III exposure.
(SEVERE EXPOSURE)
PEP by Category of Exposure and immunological status/previous immunization
PEP Components includes:
- Local wound treatment
- Local wound treatment
- Rabies Vaccines
Read table below:
If an individual has a repeat exposure less than 3 month after a previous
exposure, and has already received a complete PEP, only wound treatment is
required; neither vaccine nor RIG is needed.
Persons who cannot document previous pre- or post-exposure prophylaxis,
should be treated as a fresh case and given complete PEP
The only documented cases of human-to-human transmission occurred via tissue and organ transplants from RABV-infected individuals, and a single case of likely perinatal RABV transmission via transplant was reported.
Dose of Vaccine
All animal bite victims of Category II and III exposures, irrespective of
age and body
weight, require the same number of injections and dose per injection.
PEP for immunilogically naive case:
0.1 ml on each site, intradermal rute, on days 0, 3, 7 at rate of number
of injections 2-2-2-0-0 in deltoid or lateral thigh while deltid being
preferred.
PEP for immunized case:
0.1 ml on each site, intradermal rute, on days 0, 3 at rate of number of
injections 1-1-0-0-0 in deltoid or lateral thigh while deltid being
preferred.
Note: intramuscular regimen is not used as ID gives same immunity with
technical and financial benefits.
Dose of RIGs
The maximum dose of
• Human RIG -20 IU/kg of body weight
• Equine immunoglobulin and F(ab’)2 products- 40 IU/kg of body weight
Storage of RIGs
RIGs should be stored and transported at a temperature of +2 to 8oC and
should not be frozen.
Pre-Exposure Prophylaxis (PrEP)
WHO recommends PrEP for individuals at high risk of RABV exposure.
PEP may sometimes be necessary for the partners of patients, as close
contact and sexual intercourse in the early stages of the disease
pose a hypothetical risk for transmission (infectious RABV is present in
saliva).
Dose: 0.1 ml each site intradermal on day 0 and 7 2 sites 2-0-2-0-0 in
deltoid or lateral thigh.
Pregnant women are safe for rabies vaccination.
For full text refer to following protocol.
Thank you.
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