Is Antivenom Indicated for This Snakebite? (WHO SEARO and AFRO)
Applies WHO SEARO or AFRO criteria for antivenom after a snakebite.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Region
- South and Southeast Asia (WHO SEARO)
- Spontaneous bleeding away from the bite
- No
- 20WBCT
- Does not clot
- INR, prothrombin time or platelets
- Abnormal (INR over 1.2, PT 4-5 s over control, or platelets under 100)
- Neurotoxic signs
- No
- Low blood pressure, shock, abnormal rhythm or ECG
- No
- Acute kidney injury
- No
- Dark brown urine
- No
- Swelling of more than half the bitten limb
- Yes
- Bite on a finger or toe, with swelling
- No
The other 3 values
- Rapidly spreading swelling
- No
- Enlarged tender lymph node draining the limb
- No
- Previous reaction to horse or sheep serum, or severe allergy or asthma
- No
Result: Antivenom is indicated: systemic envenoming (a non-clotting 20WBCT and an abnormal INR, prothrombin time or platelet count).
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Region
- Spontaneous bleeding away from the bite
- 20WBCT
- INR, prothrombin time or platelets (Asia)
- Neurotoxic signs (drooping eyelids, eye movement paralysis, weakness)
- Low blood pressure, shock, abnormal rhythm or ECG
- Acute kidney injury (Asia)
- Dark brown urine (Asia)
- Swelling of more than half the bitten limb (within 48 hours, no tourniquet)
- Bite on a finger or toe, with swelling
The other 4 fields
- Rapidly spreading swelling (past the wrist or ankle within hours)
- Enlarged tender lymph node draining the limb (Asia)
- Africa: species known to cause tissue death (Bitis, Echis, Cerastes, Macrovipera, spitting cobras)
- Previous reaction to horse or sheep serum, or severe allergy or asthma
How this is calculated
Citation
Warrell DA, for WHO SEARO. Guidelines for the management of snakebites. 2nd ed. 2016, pp. 129-134, 141-142. WHO AFRO. Guidelines for the prevention and clinical management of snakebite in Africa. 2010, pp. 77-78 (Table 14.1). Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.