Cambodia - Very Venomous Snakes Found - Ovophis monticola

Ovophis monticola

Family: Viperidae

Subfamily: Crotalinae

Genus: Ovophis

Species: monticola

Subspecies: monticola , convictus, makazayazaya , orientalis , zhaokentangi

Common Names: Mountain Pit Viper , Blotched Pit Viper , Mountain Iron-head Snake , Chinese Mountain Pit Viper , Western Mountain Pit Viper ( ). m. monticola ) , Indo-Malayan Mountain Pit Viper ( O. m. convictus ) , Taiwan Mountain Pit Viper ( O. m. makazayazaya ) , Oriental Mountain Pit Viper ( O. m. orientalis ) , Gaoligong Mountain Pit Viper ( O. m. zhaokentangi )

Local Names: Shan Laotietou , Ular Kapak Gunung , Ulkar Kapar

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

Countries: Bangladesh, Bhutan, Cambodia, China, Hong Kong, Indonesia, India, Laos, Malaysia, Myanmar, Nepal, Taiwan, Thailand, Vietnam, Tibet

Ovophis monticola

Taxonomy and Biology

Adult Length: 0.70 m

General Shape: Medium in length, stout bodied snake, with a very short narrow tail. Can grow to a maximum of about 1.25 metres ( depends on subspecies ). Head is large, broad, depressed, subtriangular shaped and distinct from neck. Snout is short. Eyes are small to medium in size with vertically elliptical pupils. Median dorsal scale rows are weakly keeled, outer dorsal scale rows are smooth. Dorsal scale count ( 21 to 29 ) - ( 19 to 27 ) - ( 16 to 21 ), but usually ( 23 or 25 ) - ( 23 or 25 ) - ( 19 or 21 ).

Habitat: Mountain and plateau forest regions ranging from coastal lowlands to above 2000 metres. Often found in cultivated areas, particularly tea plantations. Prefers vegetated areas but will venture near human habitation, occasionally entering dwellings.

Habits: Mainly terrestrial and nocturnal. Sluggish and docile but will bite if provoked.

Prey: Feeds mainly on rodents, lizards, small mammals and insectivores.

Ovophis monticola

Venom

General: Venom Neurotoxins	Probably not present
General: Venom Myotoxins	Probably not present
General: Venom Procoagulants	Mixture of procoagulants
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	Rate of Envenoming: Unknown but likely to be moderate
General: Untreated Lethality Rate	Unknown but has caused deaths
General: Local Effects	Insufficient clinical reports to know, but possibly marked local effects; pain, severe swelling, bruising, but probably not necrosis
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, abdominal pain, diarrhoea, dizziness, collapse or convulsions
General: Neurotoxic Paralysis	Unlikely to occur
General: Myotoxicity	Unlikely to occur
General: Coagulopathy & Haemorrhages	No reports of coagulopathy, though related species can cause bleeding problems
General: Renal Damage	Insufficient clinical reports to know
General: Cardiotoxicity	Unlikely to occur
General: Other	Shock secondary to fluid shifts due to local tissue injury is possible in severe cases

First Aid

Description:

First aid for bites by Viperid snakes likely to cause significant local injury at the bite site.

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.

Treatment

Treatment Summary: Bites by these snakes are not well documented, but probably cause moderate to severe local effects, with shock, but not necrosis, and major coagulopathy. In the absence of specific antivenom, treatment is generally supportive & symptomatic. In severe cases, consider Japanese mamushi antivenom. Bites by these snakes are not well documented, but probably cause moderate to severe local effects, with shock, but not necrosis, and major coagulopathy. In the absence of specific antivenom, treatment is generally supportive & symptomatic. In severe cases, consider Japanese mamushi antivenom.

Key Diagnostic Features: Local pain, swelling, blistering, necrosis + coagulopathy, bleeding, shock

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: No antivenom available

Antivenoms

1. Antivenom Code: SAsCRI01

Antivenom Name: Polyvalent Anti Snake Venom Serum

Manufacturer: Central Research Institute

Phone: ++91-1-792-72114

Address: Kasauli (H.P.) 173204

Country: India

2. Antivenom Code: SAsTRC01

Antivenom Name: Green Pit Viper Antivenin

Manufacturer: Science Division, Thai Red Cross Society

Phone: ++66-2-252-0161 (up to 0164)

Address: Queen Saovabha Memorial Institute

1871 Rama IV Road

Pathumwan

Bangkok 10330

Country: Thailand

3. Antivenom Code: SAsVCT02

Antivenom Name: Bivalent Antivenin Pit Viper, Trimeresurus antivenin

Manufacturer: National Institute of Preventative Medicine

Phone: +886-2-2395-9825

Address: Linshen Office Address:

No.6, Linshen S. Rd., Taipei, Taiwan 100,

R.O.C.

Kunyang Office Address:

No.161, KunYang St., Taipei, Taiwan 115,

R.O.C.

Country: Taiwan

Source: Clinical Toxinology Resources