Family: Viperidae
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Subfamily: Viperinae
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Genus: Causus
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Species: bilineatus
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Common Names
Lined Night Adder , Two-striped Night Adder , Two-lined Night Adder
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Region
Sub-Saharan Africa
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Countries
Angola, Democratic Republic of Congo, Rwanda, Zambia
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Taxonomy and Biology
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Adult Length: 0.40 m
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General Shape
Small in length, cylindrical to slightly depressed, medium bodied snake with a short tail. Can grow to a maximum of about 0.65 metres. Head is medium in size, narrow and elongate for this genus and moderately distinct from neck. Canthus is obtuse. Snout is short, pointed but not upturned. Eyes are medium in size with round pupils. Dorsal scales are soft and feebly keeled with apical pits.
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Habitat
Moist savanna, forest savanna mosaic, particularly in swampy regions.
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Habits
Terrestrial and mainly nocturnal and more aquatic than other species of the genus. In spite of the common name, it is often active during the day. When inactive tends to hide in holes, under bush or fallen logs etc. If disturbed and angered will inflate its body with air and hiss and puff. If provoked it will raise the anterior of the body off the ground, into a coil with the head tilted back and strike, tending to lash rather than stab.
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Prey
Feeds mainly on frogs and toads.
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Venom
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General: Venom Neurotoxins
Unknown
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General: Venom Myotoxins
Unknown
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General: Venom Procoagulants
Unknown
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General: Venom Anticoagulants
Unknown
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General: Venom Haemorrhagins
Unknown
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General: Venom Nephrotoxins
Unknown
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General: Venom Cardiotoxins
Unknown
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General: Venom Necrotoxins
Unknown
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General: Venom Other
Unknown
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Clinical Effects
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General: Dangerousness
Unknown, but unlikely to cause significant envenoming, most unlikely to be dangerous.
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General: Rate of Envenoming: Unknown
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General: Untreated Lethality Rate: Unlikely to prove lethal
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General: Local Effects
Local pain & swelling
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General: Local Necrosis
Does not occur, based on current clinical evidence
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General: General Systemic Effects
Fever
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General: Neurotoxic Paralysis
Does not occur, based on current clinical evidence
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General: Myotoxicity
Does not occur, based on current clinical evidence
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General: Coagulopathy & Haemorrhages
Does not occur, based on current clinical evidence
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General: Renal Damage
Does not occur, based on current clinical evidence
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General: Cardiotoxicity
Does not occur, based on current clinical evidence
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General: Other
Does not occur, based on current clinical evidence
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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
Most cases will be minor, requiring observation, symptomatic treatment only. No antivenom available.
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Key Diagnostic Features
Local pain, swelling, lymphadenopathy, fever
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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
No antivenom available
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