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Family: Viperidae
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Subfamily: Crotalinae
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Genus: Cerrophidion
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Species: tzotzilorum
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Common Names
Tzotzil Montane Pit Viper
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Local Names
Nauyaca del Frio , Vibora , Nauyaca de Tzotzil
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Region
Central America
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Countries
Mexico
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Taxonomy and Biology
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Adult Length: 0.35 m
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General Shape
Small in length, moderately stout bodied snake with a short tapering tail. Can grow to a maximum of about 0.55 metres. Head is weakly triangular when viewed from above and distinct from neck. Eyes are medium to moderately large in size with vertically elliptical pupils. Snout is not elevated. Dorsal scales are keeled. Dorsal scale count usually 23 - 21 - 17.
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Habitat
Humid pine-oak forest.
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Habits
Diurnal and terrestrial snake.
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Venom
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General: Venom Neurotoxins
Probably not present
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General: Venom Myotoxins
Probably not present
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General: Venom Procoagulants
Possibly present
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General: Venom Anticoagulants
Probably not present
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General: Venom Haemorrhagins
Possibly present but not clinically significant
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General: Venom Nephrotoxins
Probably not present
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General: Venom Cardiotoxins
Probably not present
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General: Venom Necrotoxins
Probably not present
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General: Venom Other
Unknown
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Clinical Effects
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General: Dangerousness
Unknown, but potentially lethal envenoming, though unlikely, cannot be excluded.
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General: Rate of Envenoming: Unknown but likely to be moderate
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General: Untreated Lethality Rate: Unknown but may cause major envenoming
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General: Local Effects
Insufficient clinical reports to know, but possibly mild to moderate local effects; pain, swelling, bruising, blistering, possibly necrosis
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General: Local Necrosis
Potentially may occur, but uncommon to rare
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General: General Systemic Effects
Insufficient clinical reports to know, but might develop systemic symptoms in severe cases; headache, nausea, vomiting, abdominal pain, collapse
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General: Neurotoxic Paralysis
Insufficient clinical reports to know, but unlikely to occur
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General: Myotoxicity
Insufficient clinical reports to know, but unlikely to occur
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General: Coagulopathy & Haemorrhages
Insufficient clinical reports to know, but potentially may occur in moderate to severe cases
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General: Renal Damage
Insufficient clinical reports to know, but unlikely to occur
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General: Cardiotoxicity
Insufficient clinical reports to know, but unlikely to occur
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General: Other
Insufficient clinical reports to know
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First Aid
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Description: First aid for bites by Viperid snakes likely to cause significant local injury at the bite site (see listing in Comments section).
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Details
1. After ensuring the patient and onlookers have moved out of range of further strikes by the snake, the bitten person should be reassured and persuaded to lie down and remain still. Many will be terrified, fearing sudden death and, in this mood, they may behave irrationally or even hysterically. The basis for reassurance is the fact that many venomous bites do not result in envenoming, the relatively slow progression to severe envenoming (hours following elapid bites, days following viper bites) and the effectiveness of modern medical treatment. 2. The bite wound should not be tampered with in any way. Wiping it once with a damp cloth to remove surface venom is unlikely to do much harm (or good) but the wound must not be massaged. 3. All rings or other jewellery on the bitten limb, especially on fingers, should be removed, as they may act as tourniquets if oedema develops. 4. The bitten limb should be immobilised as effectively as possible using an extemporised splint or sling; if available, crepe bandaging of the splinted limb is an effective form of immobilisation. 5. If there is any impairment of vital functions, such as problems with respiration, airway, circulation, heart function, these must be supported as a priority. In particular, for bites causing flaccid paralysis, including respiratory paralysis, both airway and respiration may be impaired, requiring urgent and prolonged treatment, which may include the mouth to mask (mouth to mouth) technique of expired air transfer. Seek urgent medical attention. 6. Do not use Tourniquets, cut, suck or scarify the wound or apply chemicals or electric shock. 7. Avoid peroral intake, absolutely no alcohol. No sedatives outside hospital. If there will be considerable delay before reaching medical aid, measured in several hours to days, then give clear fluids by mouth to prevent dehydration. 8. If the offending snake has been killed it should be brought with the patient for identification (only relevant in areas where there are more than one naturally occurring venomous snake species), but be careful to avoid touching the head, as even a dead snake can envenom. No attempt should be made to pursue the snake into the undergrowth as this will risk further bites. 9. The snakebite victim should be transported as quickly and as passively as possible to the nearest place where they can be seen by a medically-trained person (health station, dispensary, clinic or hospital). The bitten limb must not be exercised as muscular contraction will promote systemic absorption of venom. If no motor vehicle or boat is available, the patient can be carried on a stretcher or hurdle, on the pillion or crossbar of a bicycle or on someone's back. 10. Most traditional, and many of the more recently fashionable, first aid measures are useless and potentially dangerous. These include local cauterization, incision, excision, amputation, suction by mouth, vacuum pump or syringe, combined incision and suction ("venom-ex" apparatus), injection or instillation of compounds such as potassium permanganate, phenol (carbolic soap) and trypsin, application of electric shocks or ice (cryotherapy), use of traditional herbal, folk and other remedies including the ingestion of emetic plant products and parts of the snake, multiple incisions, tattooing and so on.
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Treatment
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Treatment Summary
The minor pit vipers of South & Central America are poorly defined clinically. They appear likely to cause mostly mild to moderate local effects only, but potentially might cause more severe local effects and systemic effects, most likely coagulopathy & bleeding. There are no specific antivenoms, but most are covered by one or more regional pit viper antivenoms, which should be used for moderate to severe envenoming. In less severe cases treatment is symptomatic.
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Key Diagnostic Features
Local pain, swelling ± coagulopathy & haemorrhage in severe cases
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General Approach to Management
It is possible that most cases will be minor, but some cases may be more severe, requiring admission and treatment, so assess carefully before discharge.
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Antivenom Therapy
Only antivenoms available are for related species, but should be used for significant envenoming
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1. Antivenom Code: SAmICP01
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Antivenom Name: Polyvalent Antivenom
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Manufacturer: Instituto Clodomiro Picado
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Phone: ++506-2511-7888
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Address: Contiguo a la plaza de deportes, Dulce Nombre de Coronado. San José Costa Rica
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Country: Costa Rica
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2. Antivenom Code: SAmIBB03
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Antivenom Name: Soro antibotropico-laquetico
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Manufacturer: Instituto Butantan
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Phone: +55-11-3726-7222
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Address: Av. Vital Brasil, 1500 Butanta 05503-900 Sao Paulo - SP
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Country: Brazil
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3. Antivenom Code: SAmIBB05
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Antivenom Name: Soro botropico
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Manufacturer: Instituto Butantan
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Phone: +55-11-3726-7222
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Address: Av. Vital Brasil, 1500 Butanta 05503-900 Sao Paulo - SP
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Country: Brazil
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4. Antivenom Code: SAmIBB07
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Antivenom Name: Soro antibotropico-crotalico
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Manufacturer: Instituto Butantan
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Phone: +55-11-3726-7222
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Address: Av. Vital Brasil, 1500 Butanta 05503-900 Sao Paulo - SP
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Country: Brazil
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5. Antivenom Code: SAmIBM06
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Antivenom Name: Antivipmyn
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Manufacturer: Instituto Bioclon
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Phone: ++56-65-41-11
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Address: Calzada de Tlalpan No. 4687 Toriello Guerra C.P. 14050 Mexico, D.F.,
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Country: Mexico
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