Walterinnesia aegyptia
Family: Elapidae
Subfamily: Elapinae
Genus: Walterinnesia
Species: aegyptia
Common Names
Black Desert Cobra , Walter Innes' Snake
Local Names
Iyah
Region
Middle East + North Africa
Countries
Egypt, Israel, Jordan, Lebanon, Saudi Arabia, Syria
 
Taxonomy and Biology
Adult Length: 0.50 m
General Shape
Medium in length, medium, cylindrical bodied snake with a short tail. Can grow to about 1.30 metres. Head is moderately small, broad, flattened and slightly distinct from neck. Snout is broad, sharply edged with a distinct canthus rostralis. Eyes are small in size with round pupils. Dorsal scales are smooth anteriorly and and weakly keeled on the posterior body and tail and glossy throughout. Dorsal scale count 27 ( 23 to 29 ) - 23 ( 21 - 25 ) - 17.
Habitat
Desert ( excluding completely sand desert ) and rocky terrain and extending into the foothills of vegetated Mediterranean terrain. Often found near human habitation in irrigated agricultural settlements.
Habits
Nocturnal and mainly terrestrial snake. Most active around midnight. Spends all of its activity on the ground surface and has no subterranean tendencies. Forages for prey and rather than envenomate its prey with open mouth, usually bites its prey sideways at short distance and often uses constriction and suffocation techniques. In spite of some isolated reports of aggression, it is not particularly aggressive and even when stepped upon will usually try to escape rather than immediately bite. Venom is not injected immediately when it bites but released seconds later with chewing movement.
Prey
Feeds mainly on lizards, skinks, geckos, agamids, snakes, toads and occasionally mice and birds. It will also readily accept dead food.
Species Map
Small (Approx 20k) version
 
Venom
General: Venom Neurotoxins
Postsynaptic neurotoxins
General: Venom Myotoxins
Probably not present
General: Venom Procoagulants
Not present
General: Venom Anticoagulants
Not present
General: Venom Haemorrhagins
Not present
General: Venom Nephrotoxins
Not present
General: Venom Cardiotoxins
Not present
General: Venom Necrotoxins
Probably not present
General: Venom Other
Unknown
 
Clinical Effects
General: Dangerousness
Unknown, but potentially lethal envenoming, though unlikely, cannot be excluded.
General: Rate of Envenoming: Unknown
General: Untreated Lethality Rate: Unknown but lethal potential cannot be excluded
General: Local Effects
Insufficient clinical reports to know, but most likely minor local pain & swelling only
General: Local Necrosis
Does not occur, based on current clinical evidence
General: General Systemic Effects
Variable non-specific effects which may include headache, nausea, vomiting, fever.
General: Neurotoxic Paralysis
Insufficient clinical reports to know, but flaccid paralysis might occur, though is not reported so far.
General: Myotoxicity
Does not occur, based on current clinical evidence
General: Coagulopathy & Haemorrhages
Does not occur, based on current clinical evidence
General: Renal Damage
Does not occur, based on current clinical evidence
General: Cardiotoxicity
Does not occur, based on current clinical evidence
General: Other
Unknown
 
First Aid
Description: First aid for bites by Elapid snakes which do not cause significant injury at the bite site (see Comments for partial listing), but which may have the potential to cause significant general (systemic) effects, such as paralysis, muscle damage, or bleeding.
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. For Australian snakes only, do not wash or clean the wound in any way, as this may interfere with later venom detection once in a hospital.
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. If the bite is on a limb, a broad bandage (even torn strips of clothing or pantyhose) should be applied over the bitten area at moderate pressure (as for a sprain; not so tight circulation is impaired), then extended to cover as much of the bitten limb as possible, including fingers or toes, going over the top of clothing rather than risking excessive limb movement by removing clothing. The bitten limb should then be immobilised as effectively as possible using an extemporised splint or sling.
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.
 
Treatment
Treatment Summary
Bites are poorly documented, but expect local pain, swelling, probably not necrosis, general systemic effects, possibly flaccid paralysis. Antivenom is available; use at first sign of paralysis or for intractable general systemic effects, such as persistent vomiting not responding to antiemetics.
Key Diagnostic Features
Local pain & swelling + general systemic symptoms ± flaccid paralysis
General Approach to Management
All cases should be treated as urgent & potentially lethal. Rapid assessment & commencement of treatment including appropriate antivenom (if indicated & available) is mandatory. Admit all cases.
Antivenom Therapy
Antivenom is the key treatment for systemic envenoming. Multiple doses may be required.
Antivenoms
1. Antivenom Code: SAfAVC02
Antivenom Name: Polyvalent Snake Antivenom
Manufacturer: National Antivenom and Vaccine Production Centre
Phone: ++966-1-252-0088 ext 45626, 45637.
Address: P.O. Box 22490
Riyadh 11426
Country: Saudi Arabia
2. Antivenom Code: SAfAVC03
Antivenom Name: Bivalent Naja / Walterinnesia Snake Antivenom
Manufacturer: National Antivenom and Vaccine Production Centre
Phone: ++966-1-252-0088 ext 45626, 45637.
Address: P.O. Box 22490
Riyadh 11426
Country: Saudi Arabia
3. Antivenom Code: SAfVAC02
Antivenom Name: Polyvalent Snake Venom Antiserum
Manufacturer: VACSERA
Phone: (+20 2) 3761-1111
Address: 51 Wezaret El Zeraa St., Agouza, Giza, 22311
Country: Egypt
 
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