Cambodia - Very Venomous Snakes Found - Rhabdophis chrysargos

Rhabdophis chrysargos

Family: Colubridae

Subfamily: Natricinae

Genus: Rhabdophis

Species: chrysargos

Common Names: Speckle-bellied Keelback

Region: Southeast Asia

Countries: Brunei, Cambodia, China, Hong Kong, Indonesia, Laos, Malaysia, Myanmar, Philippines, Thailand, Vietnam

Rhabdophis chrysargos

Taxonomy and Biology

Adult Length: 0.50 m

General Shape: Small in length, cylindrical, elongate, slender bodied snake with a medium to moderately long tail. Can grow to a maximum of about 0.95 metres. Head is elongate and distinct from neck. Eyes are moderately large in size with round pupils. Dorsal scales are strongly keeled with apical pits. Ventrals are rounded. Dorsal scale count usually 19 - 19 - 17.

Habitat: Tropical wet lowland forest, tropical and subtropical montane forest, bamboo thickets, woodlands and scrublands, marshes, swamps and urban areas near water. Most often found near water in mountain or hill terrain up to an elevation of about 1700 metres, but also very common in lowlands.

Habits: Diurnal and terrestrial snake that will climb into small trees.

Prey: Feeds mainly on frogs, lizards, mice, small birds and fish.

Rhabdophis chrysargos

Venom

General: Venom Neurotoxins	Probably not present
General: Venom Myotoxins	Probably not present
General: Venom Procoagulants	Possibly present
General: Venom Anticoagulants	Possibly present
General: Venom Haemorrhagins	Possibly present
General: Venom Nephrotoxins	Probably not present
General: Venom Cardiotoxins	Probably 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 but likely to be low
General: Untreated Lethality Rate	Unknown but lethal potential cannot be excluded
General: Local Effects	Insufficient clinical reports to know, but possibly local pain, swelling, bruising & bleeding
General: Local Necrosis	Insufficient clinical reports to know, but local necrosis most unlikely
General: General Systemic Effects	Insufficient clinical reports to know, but systemic effects cannot be excluded and might include one or more of headache, nausea, vomiting, abdominal pain, diarrhoea, dizziness, collapse or convulsions
General: Neurotoxic Paralysis	Insufficient clinical reports to know, but unlikely to occur
General: Myotoxicity	Insufficient clinical reports to know, but unlikely to occur
General: Coagulopathy & Haemorrhages	Insufficient clinical reports to know, but possibly moderate to severe coagulopathy
General: Renal Damage	Insufficient clinical reports to know, but could potentially occur as a complication of coagulopathy
General: Cardiotoxicity	Insufficient clinical reports to know, but unlikely to occur
General: Other	Insufficient clinical reports to know

First Aid

Description:

First aid for potentially dangerous non-front-fanged colubroid snakes (see listing in Comments section).

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: Bites by these non-front-fanged colubroid snakes are rarely , if ever reported. While there is currently no direct case experience to suggest they may cause major envenoming, closely related species are known, on occasion, to cause severe, even fatal envenoming. Therefore all members of this genus should be considered as possibly able to cause significant envenoming. The two species known to envenom humans, R. tigrinus and R. subminiatus, can cause major envenoming, with potentially lethal coagulopathy.

Key Diagnostic Features: Bites may cause no more than mild local swelling & pain, but more severe effects, such as local pain, swelling + coagulopathy & haemorrhage, cannot be excluded.

General Approach to Management: Most cases may be minor & not require admission, but more severe effects cannot be excluded. All cases should be treated as urgent & potentially (though unlikely to be ) lethal. Rapid assessment & commencement of treatment including appropriate antivenom (if indicated & available) is mandatory. However, it is likely very few, if any, cases will warrent antivenom therapy. Admit all cases where systemic envenoming develops.

Antivenom Therapy: Only antivenoms available are for related species, but should be used for significant envenoming

Antivenoms

No Antivenoms

Source: Clinical Toxinology Resources