ENVENOMING CAUSED BY BRAZILIAN SNAKES

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ENVENOMING CAUSED BY BRAZILIAN SNAKES

• BENEDITO BARRAVIERA
• Full Professor of Tropical Diseases
• Botucatu Medical School - UNESP
• Research from The Center for the Study of Venoms
  and Venomous Animals CEVAP
• São Paulo State University - UNESP - Brazil

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MAIN BRAZILIAN SNAKES
From Public Health point of view 1-Venomous
snakes (about 58 species) Viperidae family
Bothrops sp (28 species) Crotalus sp (6
sub-species) Lachesis sp (2
species) Elapidae family Micrurus sp (22
species) 2-Nonvenomous snakes (about 250
species) Boidae family - Boa constrictor,
Eunectus murinus, Corallus caninus, Epicrates
cenchria (11 species) Colubridae family Clelia
clelia, Liophis frenatus, Philodryas olfersii,
Dipsas albifrons, Spilotis pullatus, Waglerophis
merremii, Mastigodryas bifossatus, etc. (239
species)
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MAIN BRAZILIAN VENOMOUS SNAKES

• Viperidae family
• Bothrops sp Bothrops jararaca, B. alternatus,
  B. moojeni, B. atrox (from Amazon region), B.
  cotiara, B. erytromelas, etc.
• -Responsible for 80 to 90 of accidents in Brazil
• Crotalus sp Crotalus durissus terrificus, C. d.
  collilineatus, C. d. marajoensis, C. d.
  cascavella, C. d. trigonicus, C. d. ruruima
• -Responsible for 10 to 20 of accidents in Brazil
• -Lachesis sp Lachesis muta muta, Lachesis muta
  rhombeata
• -Responsible for 3 of accidents in the Amazon
  region - Brazil.

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Bothrops sp distribution
Bothrops alternatus
Bothrops moojeni
Bothrops jararaca
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Bothrops moojeni
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Crotalus sp distribution
Crotalus durissus terrificus (South American
rattlesnake)
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Crotalus durissus terrificus
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MAIN BRAZILIAN VENOMOUS SNAKES IN AMAZON REGION
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MAIN BRAZILIAN VENOMOUS SNAKES IN THE AMAZON
REGION
Bothrops atrox Bothrops brazili Bothriopsis
bilineata Bothriopsis teniata Lachesis muta muta

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MAIN BRAZILIAN VENOMOUS SNAKES IN THE AMAZON
REGION
Bothrops atrox
Lachesis muta muta
Bothriopsis bilineata
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Lachesis muta muta
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MAIN BRAZILIAN VENOMOUS SNAKES
Elapidae family -Micrurus sp Micrurus
frontalis, M. corallinus, M. paraensis, M.
spixii, M. filiforms, etc. -Responsible for less
than 1 of accidents in Brazil
Micrurus corallinus
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Micrurus sp distribution
Micrurus frontalis
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Boa constrictor
Boidae family Nonvenomous snakes
Corallus caninus
Eunectus murinus
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Colubridae family Nonvenomous snakes
Philodryas olfersii
Liophis miliaris
Spilotes pullatus
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EPIDEMIOLOGY
Accidents caused by venomous animals in
Brazil Snakes 30,000/year Scorpions
35,000/year Spiders 19,500/year Bees and
wasps 1,500/year Catterpilars 500/year São
Paulo State 2,000/year Botucatu 100/year
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EPIDEMIOLOGY
Main season Summer from December to
March Patients characteristics Rural workers,
Male (74.84) , 15 to 49 years old, lower limbs
(62.75) Snakes characteristics 87.33 Bothrops
sp envenoming 7.43 Crotalus sp envenoming 1.37
Lachesis sp envenoming 0.41 Micrurus sp
envenoming The Amazon region 3,000
cases/year 90 Bothrops sp envenoming 10
Lachesis sp and others
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Bothropic envenoming Clinical aspects
Venom activity Bothrops sp 1-Coagulative
activity cause bleeding and clotting
disturbances
Bothrops alternatus
Patient with severe gingival bleeding
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Bothropic envenoming Clinical aspects
Venom activity Bothrops sp 2-Citotoxic venom
activity citotoxicity - capacity to destroy
tissues
Bothrops alternatus
Mild bothropic envenomings
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Bothropic envenoming Clinical aspects
Venom activity Bothrops sp 2-Citotoxic venom
activity citotoxicity - capacity to destroy
tissues
Bothrops alternatus
Moderate bothropic envenomings
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Bothropic envenoming Clinical aspects
Venom activity Bothrops sp 2-Citotoxic venom
activity citotoxicity - capacity to destroy
tissues
Bothrops alternatus
Severe bothropic envenomings
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Bothropic envenoming Clinical aspects
Venom activity Bothrops sp 3-Hemorrhaging
activity spontaneous hemorrhage by damaging
vascular endothelium
Bothrops alternatus
Patients develop local or distant hemorrhage
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Crotalic envenoming Clinical aspects
Venom activity Crotalus sp 1-Neurotoxic
activity neurotoxic symptoms
Crotalus durissus terrificus
Midriasis
Local bite
Ptosis, Diplopia and blurred vision
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Crotalic envenoming Clinical aspects
Venom activity Crotalus sp 2-Systemic
rhabdomyolyses skeletal muscle
Crotalus durissus terrificus
Rhabdomyolysis
Myoglobinuria
Increase of CPK, DHL, AST and ALT enzymes
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Crotalic envenoming Clinical aspects
Venom activity Crotalus sp 3-Renal failure
Crotalus durissus terrificus
Tubular necrosis causing renal failure
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Crotalic envenoming Clinical aspects
Venom activity Crotalus sp 4-Liver toxicity
Crotalus durissus terrificus
Liver cells with mitochondrial edema Increase of
Alanine aminotransferase enzyme
Liver necrosis
Liver with edema
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Lachetic envenoming Clinical aspects
Venom activities like Bothrops
sp 1-Coagulative cause bleeding and clotting
disturbances 2-Citotoxic citotoxicity -
capacity to destroy tissues 3-Hemorrhaging
spontaneous hemorrhage by damaging vascular
endothelium 4-Neurotoxic bradicardia,
diarrhea and arterial hipotension including
shock
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Elapidic envenoming Clinical aspects

• This venom
• low molecular weight neurotoxins
• neurotoxic facial expression (bilateral ptosis)
• respiratory muscle paralysis.
• The most severe Brazilian ophidic accident!

Neurotoxic facial expression
Micrurus corallinus
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MANAGEMENT OF THE SNAKEBITE
The early specialized medical assistance is
essential to the evolution and prognosis of the
patient All victims should be hospitalized
and observed for at least 24 hours
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Make the patient rest. If possible, wash the bite
area with soap and waterGo to nearest hospital
or medical facility as soon as possible where
there is antivenom to be appliedKeep the
bitten extremity above the level of the heart
If possible, try to identify the snake and
take it to the hospitalTetanus
immunoprophylaxis is recommended.
What to DO immediately ?
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No ice or any other type of cooling on the bite.
Research has shown this to be potentially
harmful No tourniquets. This cuts blood flow
completely and may result in loss of the affected
limbNo electric shock. This method is under
study and has yet to be proven effective. It
could harm the victimNo incisions, no suction
in the wound. Such measures have not been proven
useful and may cause infection and persistent
bleedingDo not give beverages (alcohol or any
other drink).
What NOT to do
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SPECIFIC ANTIVENOM TREATMENT
Viperidae family Bothrops sp -Mild accident -
4 (100 mg) antibotropic venom ampules by
intravenous route without allergic
test -Moderate accident - 8 (200 mg)
antibotropic venom ampules by intravenous route
without allergic test -Severe accident - 12
(300 mg) antibotropic venom ampules by
intravenous route without allergic test.
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1-Hospitalize the patient for at least 24
hours2-Make the Clotting Test after 12 hours
to evaluate the clotting disturbance and
indicate, if necessary, more antivenom3-Clean
and wash the bite region4-Hydrate by
intravenous route5-Give antibiotic prophylaxis
with cefuroxime 125 to 250 mg twice a
day6-Recommend tetanus immunoprophylaxis.
SUPPORTIVE TREATMENT
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SPECIFIC ANTIVENOM TREATMENT
Viperidae family Crotalus sp -Mild accident -
10 (100 mg) anticrotalic venom ampules by
intravenous route without allergic
test -Moderate accident - 20 (200 mg)
anticrotalic venom ampules by intravenous route
without allergic test -Severe accident - 30
(300 mg) anticrotalic venom ampules by
intravenous route without allergic test.
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1-Hospitalize the patient for at least 24
hours2-Make Clotting Test after 12 hours to
evaluate clotting disturbance and indicate, if
necessary, more antivenom3-Clean and wash the
bite region4-Hidrate to prevent renal failure
with Manitol 20, four times a day for at least 5
days. 5-Increase pH with Sodium bicarbonate 5
, 50 ml by oral route, four times a day. 5-Give
antibiotic prophylaxis cefuroxime 125 to 250
mg twice a day, for 5 to 7 days6-Indicate
tetanus immunoprophylaxis7-If renal failure
occurs hemodyalisis.
SUPPORTIVE TREATMENT
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SPECIFIC ANTIVENOM TREATMENT
Viperidae family Lachesis sp Apply 10 to 20
antilachetic or antibotropic/lachetic venom
ampules by intravenous route without allergic
test Supportive treatment Bothrops
sp These accidents the Amazon
region.
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SPECIFIC ANTIVENOM TREATMENT
Elapidade family Micrurus sp Apply 10 (150
mg) antielapidic venom ampules by intravenous
route without allergic test Supportive
treatment to prevent neurotoxic
effects Respiratory paralysis
Atropine, neostigmine and edrophonium chloride
are indicated. Less than 1 of accidents occur
in Brazil every year.
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Prevention of Antivenom Reactions according to
Health Ministry
-Pre-medication - 10 to 15 minutes before
antivenom treatment -Dextroclorfeniramine
(Polaramine) 0.08 or Prometazine (Fenergan)
0.6 mg/Kg mg/Kg by intramuscular
route-Hidrocortisone (Solu-cortef) 10 mg/Kg
by intravenous route
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Prevention of Antivenom Reactions according to
Health Ministry
-Cimetidine (Tagamet) 10 mg/Kg or Ranitidine
(Antak) 2 mg/Kg by intravenous
route-Antivenom, without dilution, for 15 to 30
minutes, by intravenous route without allergic
test
Medical supervision must be continuous during
antivenom administration
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NONVENOMOUS SNAKE ACCIDENTS
Boidae family No envenomation Wash the bite
area with soap and water Inform the patient
that antivenom treatment is not necessary.
Accident with Boa constrictor
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NONVENOMOUS SNAKE ACCIDENTS
Colubridae family -Rare envenomation -Rare
pain and local swelling -Rare partial
defibrination -Controversial antibotropic treatm
ent.
Envenomation by Philodryas olfersii
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This lecture is available athttp//www.barravie
ra.med.brEmailbbviera_at_jvat.org.brbbviera_at_gnosi
s.com.br
Thank you very much!