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Understanding Rabies And How To Manage Animal Bites |
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Rabies is 100%
fatal |
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Rabies is preventable,
provided proper wound care, correct use of vaccines and immunoglobulin
is undertaken |
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Incorrect or wrong treatment
of animal bite wounds may lead to rabies and death |
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Dogs are mainly responsible
for rabies. Cats, monkeys, wolves and bears are known to occasionally
cause rabies. However none of us has definitely seen such
a case |
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Rats, mice, squirrels
or birds do not transmit rabies |
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Saliva and urine are the
main source of virus infection |
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Bites, scratches or licks
from a rabid animal over broken skin can be dangerous |
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The virus multiplies locally
and travels inside nerves and not through blood |
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Wounds or exposures should be categorized according to WHO
classification I, II, III as this helps the clinician in assessing
danger from a bite:
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| Category
1 |
Touching
or feeding animals or licks on intact skin. (No risk)
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| Category
II |
Minor scratch or abrasion
without bleeding, or licks on broken skin (Moderate
risk) |
| Category
III |
Wounds with
bleeding, licks on mucous membrane. (High risk) |
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| It is also very important
to elicit information about the biting animal: |
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Healthy pet and regularly vaccinated dog/cat (low risk) |
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Healthy pet and vaccination doubtful or not done (moderate
risk) |
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Rabid, sick, dying/dead or stray or escaped dog or cat or
wild animal (high risk) |
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| A category II or III exposure
from a moderate or high risk animal needs immediate anti-
rabies treatment. |
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| Rabies in a cat/dog should
be suspected if: |
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Any change in normal behavior suggesting aggression or depression |
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Running aimlessly and attacking without provocation |
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Animal is drowsy and withdrawn |
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Excessive salivation |
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Refusal to eat |
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Eating unusual objects like wood, stone, metal |
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Death of the animal due to illness |
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| Observation
of the animal for 10 days after the bite is recommended. The
rationale for this is that the animal incubating rabies generally
becomes ill in 3-4 days and dies in another 3-5 days. Hence,
if there is any doubt about the state of the animal, or the
patient is insistent on receiving vaccine, the series may
be started and if the animal remains healthy, the series may
be stopped. However, since the patient may already have received
3 doses (0,3,7) and only 2 doses remain, one may as well continue
with the last 2 doses, or give only the 4th dose, and convert
to pre-exposure prophylaxis (0,7,21 or 28 days) |
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| Wound care
and treatment |
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Wash all wounds under running water
for at least 10 minutes. This will wash out or at least dilute
the saliva |
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Clean the wound thoroughly with soap,
which is virucidal or Dettol, Savulon or Povidone |
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Don not use iodine, or household applicants
like salt, spices or other powders. These cause local irritation
and push the virus deeper into the wound |
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Do not bandage |
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Do not suture the wound |
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| Vaccine (active
immunization) |
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Use only tissue culture vaccine, not sheep
brain or any nerve tissue vaccine. |
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These have too many disadvantages and are of uncertain efficacy
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Vaccine should be administered as soon
as possible after the bite and even up to 14 days |
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Always inject into the deltoid, never
into the gluteus |
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| Three approved
tissue culture vaccines are available in Pakistan and are
equally effective.
Cost may be the only consideration. Give the patient a record
of the immunization. |
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| 1) |
Purified Chick Embryo Cell (PCEC, Rabipur®,
Chiron) |
| 2) |
Purified Vero Cell Vaccine (PVRV, Verorab®,
Aventis) |
| 3) |
Purified Duck Embryo Vaccine (PDEV,
Lyssavac®, Berna) |
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| Vaccine
schedule: Essen Regimen: Day 0,3,7,14,28. |
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| Rabies
immune globulin (RIG) for passive, immediate protection.
RIG must be given in all Category III bites, and whenever
there is high suspicion of a rabid animal bite, even if it
is Category II. |
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| Two types are available: |
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| a) |
Human, which is very expensive but risk free. Dose 20 IU /kg
body weight |
| b) |
Equine, which is less expensive and
occasionally can produce adverse effects. Dose 40 IU/kg. Skin
test must be done before injecting. |
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| Failure to
use RIG in a Category III bite is often a reason for failure
of therapy, despite correct vaccine use. |
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| Patients, especially
children need comfort and reassurance as an animal bite in
itself is painful and fearsome. |
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