In many countries, snakebite is an important medical emergency and cause of hospital admission, demanding urgent attention by adequately trained medical staff. It results in the death or chronic disability of tens of thousands of active younger people, especially those involved in farming and plantation work.

There are 48 venomous snake species in China; ten of them being medically important. Most venomous snakes inhabit the south of China. Venomous snake bites cause more than 100,000 casualties each year in China and the victims are increasing yearly due to the improvement in environmental conditions.

Since 1956, Shanghai Institute of Biological Products started the R&D for snake antivenins. In 1970, Agkistrodon Halys Antivenin was approved by SFDA, and consecutively Agkistrodon Acutus Antivenin, Bungarus Multicinctus Antivenin, and Naja naja (atra) Antivenin were developed.

Inherited from Shanghai Institute of Biological Products in 1999, Shanghai Serum Bio-technology Co., Ltd. started to produce these four snake antivenins. Shanghai Serum Bio-technology Co., Ltd. is the only domestic manufacturer of antivenin in China. The antivenin output is more than 100,000 doses per year, which can fully meet the domestic demand, with some antivenins exported to South Korea. Several new antivenins are currently in development, including Vipera russelli siamensis antivenin and sea snake antivenin.

Classification of snake venoms

Snake venoms are classified into three groups: neurotoxin, blood circulation toxin, and mixed toxin, which possesses both neurotoxic and blood circulation toxic property.

·  eurotoxins

          venoms from Bungarus fasciatus and Bungarus multicinctus

·  blood circulation toxins

          venoms from Agkistrodon acutus, Vipera russelli siamensis, Trimeresurus stejnegeri, and Trimeresurus mucrosquamatus

·  mixed toxins

          venoms from Agkistrodon halys, Naja naja atra (Cobra), and Ophiophagus Hannah (King Cobra)

The antivenins produced in Shanghai Serum Bio-technology Co. Ltd., can effectively treat snake-bite victims caused by almost all the medical important venomous snakes in China.

Management and Treatment

First-Aid: Most of the familiar methods for first-aid treatment of snakebite, both Western and “Traditional/herbal”, have been found to result in more harm (risk) than good (benefit), and should be firmly discouraged. Recommended first-aid methods emphasize reassurance, application of a pressure-pad over the bite wound, immobilization of the bitten limb, and transport of the patient to a place where they can receive medical care without delay.

Diagnosis of the species of snake responsible for the bite is important for optimal clinical management. This may be achieved through expert identification of the dead snake or a (mobile-phone) image of it, or by inference from the resulting “clinical syndrome” of envenoming.

Antivenom (species-specific hyperimmune immunoglobulin), a lifesaving, WHO-recognized, essential medicine, is the only effective antidote for envenoming. It is recommended that antivenom should be used in all patients with signs of systemic and/or severe local envenoming in whom the benefits of treatment are judged to exceed the risks of antivenom reactions. It should not be used in the absence of evidence of envenoming.

Skin/conjunctival hypersensitivity testing does not predict early or late antivenom reactions and it is recommended that these tests should not be carried out. Prophylactic subcutaneous adrenaline has proved effective in reducing the frequency and severity of early antivenom reactions and its routine use is, therefore, recommended unless the risk of reactions associated with a particular antivenom is low (less than a few %). It is recommended that whenever possible antivenom should be given by slow intravenous injection or infusion. Adrenaline should always be available in readiness at the bedside in case of an early anaphylactic antivenom reaction.

Recommended Dosages

The dosage mentioned above can neutralize the discharged venom from the corresponding snake bite, and the dose can be increased according to the victim’s condition. The dosage for children is identical to that for adults and cannot be reduced.