Cambodia - Very Venomous Snakes Found - Rhabdophis subminiatus

Rhabdophis subminiatus ( Red necked Keelback ) 

Original photo copyright © Dr Julian White

Family: Colubridae

Subfamily: Natricinae

Genus: Rhabdophis

Species: subminiatus

Subspecies: subminiatus , helleri

Common Names: Red-necked Keelback , Heller's Keelback ( R. s. helleri )

Local Names: Ular Pitjung , Ular Lempeh

Region: Indian Sub-continent + North Asia + Southeast Asia

Countries: Bangladesh, Bhutan, Brunei, Cambodia, China, Hong Kong, Indonesia, India, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, Vietnam

Rhabdophis subminiatus ( Red necked Keelback ) Original photo copyright © Dr Wolfgang Wuster

Taxonomy and Biology

Adult Length: 0.50 m

General Shape: Medium in length, moderately slender bodied snake with moderately long and slender tail. Can grow to a maximum of about 1.30 metres. Head is moderately distinct from neck, slightly elongate with a prominent brow ridge. Eyes are moderately large in size with round pupils. Dorsal scales are keeled with the outer rows smooth. Dorsal scale count usually 21 - 19 - 17.

Habitat: Wide variety of habitats throughout its tropical and subtropical mainland and island range. Found in wet forest, paddy fields, grasslands and marshes especially along streams or in lowlands or foothills near rivers and streams. Often found in or around rubber plantations.

Habits: Mainly terrestrial and diurnal but often seen swimming. Inoffensive disposition. It tends to flatten its body if disturbed and will strike if provoked or handled.

Prey: Feeds mainly on frogs, toads, small mammals and fish.

Venom

General: Venom Neurotoxins	Not present
General: Venom Myotoxins	Not present
General: Venom Procoagulants	Mixture of procoagulants
General: Venom Anticoagulants	Possibly present
General: Venom Haemorrhagins	Possibly present
General: Venom Nephrotoxins	Not present
General: Venom Cardiotoxins	Not present
General: Venom Necrotoxins	Not present
General: Venom Other	Not present or not significant

Clinical Effects

General: Dangerousness	Severe envenoming possible, potentially lethal
General: Rate of Envenoming	Unknown
General: Untreated Lethality Rate	Unknown but has caused deaths
General: Local Effects	Local pain, swelling, bruising & bleeding
General: Local Necrosis	Not likely to occur
General: General Systemic Effects	Variable non-specific effects which may include headache, nausea, vomiting, abdominal pain, diarrhoea, dizziness, collapse or convulsions
General: Neurotoxic Paralysis	Unlikely to occur
General: Myotoxicity	Not likely to occur
General: Coagulopathy & Haemorrhages	Uncommon to rare, but may be moderate to severe coagulopathy
General: Renal Damage	Recognised complication, usually secondary to coagulopathy
General: Cardiotoxicity	Unlikely to occur
General: Other	Not likely to occur

First Aid

Description:

First aid for potentially dangerous non-front-fanged colubroid snakes.

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. 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. In Australia and parts of New Guinea, Snake Venom Detection Kits are available to identify the snake from venom left on the skin.

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: Capable of major envenoming, with potentially lethal coagulopathy, reversible with specific antivenom therapy, less certainly with Cryoprecipitate/FFP, no role for heparin.

Key Diagnostic Features: Local pain, swelling + coagulopathy & haemorrhage

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: SAsJSI01

Antivenom Name: Anti-Yamakagashi Antivenom

Manufacturer: The Japan Snake Institute

Phone: ++81-277-78-5193

Address: Yabuzuka-honmachi Nittagun,

Gunma Prefecture 379-2301

Country: Japan

Source: Clinical Toxinology Resources