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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. From Public Health point of view
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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
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 - Boaconstrictor, Eunectusmurinus, Coralluscaninus, Epicrates cenchria (11 species) Colubridae family – Cleliaclelia, Liophisfrenatus, Philodryas olfersii, Dipsasalbifrons, Spilotispullatus, Waglerophismerremii, Mastigodryasbifossatus, etc. (239 species) MAIN BRAZILIAN SNAKES
Viperidae family • – Bothrops sp – Bothropsjararaca, 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 – Crotalusdurissusterrificus, 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 – Lachesismutamuta, Lachesismutarhombeata • -Responsible for 3% of accidents in the Amazon region - Brazil. MAIN BRAZILIAN VENOMOUS SNAKES
Bothrops sp distribution Bothrops alternatus Bothrops moojeni Bothrops jararaca
Crotalus sp distribution Crotalus durissus terrificus (South American rattlesnake)
Bothrops atrox* Bothrops brazili Bothriopsis bilineata Bothriopsis teniata Lachesis muta muta * MAIN BRAZILIAN VENOMOUS SNAKES IN THE AMAZON REGION
Bothrops atrox MAIN BRAZILIAN VENOMOUS SNAKES IN THE AMAZON REGION Lachesis muta muta Bothriopsis bilineata
Elapidae family -Micrurus sp – Micrurus frontalis, M. corallinus, M. paraensis, M. spixii, M. filiforms, etc. -Responsible for less than 1% of accidents in Brazil MAIN BRAZILIAN VENOMOUS SNAKES Micrurus corallinus
Micrurus sp distribution Micrurus frontalis
Boa constrictor Boidae family Nonvenomous snakes Corallus caninus Eunectus murinus
Colubridae family Nonvenomous snakes Philodryas olfersii Liophis miliaris Spilotes pullatus
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 EPIDEMIOLOGY
Main season Summer – from December to March Patient´s 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 spenvenoming The Amazon region – 3,000 cases/year 90% Bothrops sp envenoming 10% Lachesis sp and others EPIDEMIOLOGY
Venom activity – Bothrops sp 1-Coagulative activity – cause bleeding and clotting disturbances Bothropic envenoming Clinical aspects Bothrops alternatus Patient with severe gingival bleeding
Venom activity – Bothrops sp 2-Citotoxic venom activity – citotoxicity - capacity to destroy tissues Bothropic envenoming Clinical aspects Bothrops alternatus Mild bothropic envenomings
Venom activity – Bothrops sp 2-Citotoxic venom activity – citotoxicity - capacity to destroy tissues Bothropic envenoming Clinical aspects Bothrops alternatus Moderate bothropic envenomings
Venom activity – Bothrops sp 2-Citotoxic venom activity – citotoxicity - capacity to destroy tissues Bothropic envenoming Clinical aspects Bothrops alternatus Severe bothropic envenomings
Venom activity – Bothrops sp 3-Hemorrhaging activity – spontaneous hemorrhage by damaging vascular endothelium Bothropic envenoming Clinical aspects Bothrops alternatus Patients develop local or distant hemorrhage
Venom activity – Crotalus sp 1-Neurotoxic activity – neurotoxic symptoms Crotalic envenoming Clinical aspects Crotalus durissus terrificus Midriasis Local bite Ptosis, Diplopia and blurred vision
Venom activity – Crotalus sp 2-Systemic rhabdomyolyses – skeletal muscle Crotalic envenoming Clinical aspects Crotalus durissus terrificus Rhabdomyolysis Myoglobinuria Increase of CPK, DHL, AST and ALT enzymes
Venom activity – Crotalus sp 3-Renal failure Crotalic envenoming Clinical aspects Crotalus durissus terrificus Tubular necrosis causing renal failure
Venom activity – Crotalus sp 4-Liver toxicity Crotalic envenoming Clinical aspects Crotalus durissus terrificus Liver cells with mitochondrial edema Increase of Alanine aminotransferase enzyme Liver necrosis Liver with edema
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 Lachetic envenoming Clinical aspects
This venom • low molecular weight neurotoxins • neurotoxic facial expression (bilateral ptosis) • respiratory muscle paralysis. • The most severe Brazilian ophidic accident! Elapidic envenoming Clinical aspects Neurotoxic facial expression Micrurus corallinus
“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” MANAGEMENT OF THE SNAKEBITE
What to DO immediately ? Make the patient rest. If possible, wash the bite area with soap and water;Go to nearest hospital or medical facility as soon as possible where there is antivenom to be applied;Keep the bitten extremity above the level of the heart ;If possible, try to identify the snake and take it to the hospital;Tetanus immunoprophylaxis is recommended.
What NOT to do 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 limb;No electric shock. This method is under study and has yet to be proven effective. It could harm the victim;No incisions, no suction in the wound. Such measures have not been proven useful and may cause infection and persistent bleeding;Do not give beverages (alcohol or any other drink).
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. SPECIFIC ANTIVENOM TREATMENT
SUPPORTIVE TREATMENT 1-Hospitalize the patient for at least 24 hours;2-Make the Clotting Test after 12 hours to evaluate the clotting disturbance and indicate, if necessary, more antivenom;3-Clean and wash the bite region;4-Hydrate by intravenous route;5-Give antibiotic prophylaxis with cefuroxime 125 to 250 mg twice a day;6-Recommend tetanus immunoprophylaxis.
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. SPECIFIC ANTIVENOM TREATMENT
SUPPORTIVE TREATMENT 1-Hospitalize thepatient for atleast 24 hours;2-MakeClottingTestafter 12 hours to evaluateclottingdisturbanceandindicate, ifnecessary, more antivenom;3-Cleanand wash the bite region;4-Hidrate to prevent renal failurewith Manitol 20%, four times a day for atleast 5 days. 5-Increase pH withSodiumbicarbonate 5% , 50 ml by oral route, four times a day. 5-Giveantibioticprophylaxis – cefuroxime 125 to 250 mgtwice a day, for 5 to 7 days;6-Indicatetetanusimmunoprophylaxis;7-If renal failureoccurshemodyalisis.
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. 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. SPECIFIC ANTIVENOM TREATMENT
-Pre-medication - 10 to 15 minutes beforeantivenomtreatment; -Dextroclorfeniramine (Polaramine®) – 0.08 orPrometazine (Fenergan®) – 0.6 mg/Kg mg/Kg by intramuscular route;-Hidrocortisone (Solu-cortef®) – 10 mg/Kg byintravenousroute; Prevention of Antivenom Reactions according to Health Ministry
-Cimetidine (Tagamet®) – 10 mg/Kg orRanitidine (Antak®) – 2 mg/Kg byintravenousroute-Antivenom, withoutdilution, for 15 to 30 minutes, byintravenousroutewithoutallergictest; Prevention of Antivenom Reactions according to Health Ministry “Medical supervision must be continuous during antivenom administration”
Boidae family No envenomation Wash the bite area with soap and water; Inform the patient that antivenom treatment is not necessary. NONVENOMOUS SNAKE ACCIDENTS Accident with Boa constrictor
Colubridae family -Rare envenomation; -Rare pain and local swelling; -Rare partial defibrination; -Controversial antibotropic treatment. NONVENOMOUS SNAKE ACCIDENTS Envenomation by Philodryas olfersii
Thankyouverymuch! This lecture is available at:http://www.barraviera.med.brEmailbbviera@jvat.org.brbbviera@gnosis.com.br