Summary about Disease
Snakebite envenomation is a traumatic injury caused by the bite of a venomous snake. It is a significant public health problem, particularly in rural areas of tropical and subtropical countries. The severity of a snakebite depends on factors such as the species of snake, the amount of venom injected, the location of the bite, and the victim's size and health. It can cause a range of symptoms from local pain and swelling to systemic effects like bleeding disorders, paralysis, and kidney failure.
Symptoms
Symptoms of a snakebite vary depending on the type of snake and the amount of venom injected. Common symptoms include:
Local: Fang marks, pain, swelling, redness, bruising, blistering around the bite.
Systemic: Bleeding (from gums, nose, or wound), nausea, vomiting, diarrhea, abdominal pain, headache, dizziness, blurred vision, difficulty breathing, muscle weakness, paralysis, seizures, altered mental status, shock.
Causes
Snakebites are caused by the injection of venom from a venomous snake through its fangs into the skin of the victim. This typically occurs when a person accidentally steps on, disturbs, or attempts to handle a snake.
Medicine Used
The primary treatment for snakebite envenomation is antivenom (also known as antivenin). Antivenom is made by injecting venom into an animal (usually a horse or sheep) and then collecting the antibodies produced. These antibodies neutralize the venom in the human body. Additional treatments may include:
Wound care (cleaning, dressing)
Pain medication
Fluid resuscitation
Respiratory support (oxygen, mechanical ventilation)
Blood transfusions (if significant bleeding)
Treatment for kidney failure (dialysis)
Is Communicable
Snakebite is not communicable. It cannot be spread from person to person.
Precautions
Wear protective clothing (boots, long pants) when in snake-prone areas.
Avoid walking in tall grass or thick underbrush where snakes may be hiding.
Be cautious when stepping over logs or rocks.
Do not attempt to handle or approach snakes.
Use a light at night.
Keep your yard free of debris that could attract snakes (wood piles, rock piles, overgrown vegetation).
Educate yourself about the venomous snakes in your area.
If you see a snake, give it plenty of space.
How long does an outbreak last?
Snakebite is not an outbreak in the traditional sense of a communicable disease. It is an event that occurs when an individual is bitten. The "duration" refers to the time it takes for the symptoms of envenomation to resolve with or without treatment. This can range from days to weeks, depending on the severity of the bite and the effectiveness of treatment. Increased incidence of snakebites may occur seasonally, but this isn't considered an outbreak.
How is it diagnosed?
Diagnosis of snakebite is based on:
History: Circumstances of the bite, location, description of the snake (if possible).
Physical Examination: Presence of fang marks, local signs of envenomation (swelling, pain, bruising), systemic signs and symptoms.
Laboratory Tests: Complete blood count (CBC), coagulation studies (PT, PTT, fibrinogen), electrolytes, kidney function tests (BUN, creatinine), creatine kinase (CK), urinalysis. Venom detection tests (if available) can help confirm the diagnosis, but they are not always readily accessible.
Timeline of Symptoms
The timeline of symptoms varies greatly. Here is a general progression:
Immediately: Pain at the bite site, sometimes faint fang marks.
Within Minutes to Hours: Local swelling and redness, systemic symptoms like nausea, vomiting, dizziness.
Within Hours to Days: Progression of swelling, bruising, bleeding, muscle weakness, paralysis, kidney failure. The speed of progression depends on the venom and individual factors.
Days to Weeks: Resolution of symptoms with treatment. Potential for long-term complications, such as scarring, contractures, or chronic kidney disease.
Important Considerations
Identification: If possible and safe*, try to identify the snake species (or take a picture with a phone if you can do so without getting closer). This can help determine the appropriate antivenom. *Do not* risk another bite.
First Aid:
Keep the victim calm and still.
Remove constricting clothing and jewelry.
Immobilize the affected limb and keep it below the level of the heart.
Transport the victim to a medical facility as quickly as possible.
What NOT to do: Do not apply a tourniquet. Do not cut and suck out the venom. Do not apply ice. Do not administer alcohol or stimulants.
Antivenom Availability: Access to appropriate antivenom is crucial but can be limited in some regions. Prompt medical attention is essential.