What is Snake Toxicity?
Snake bites from venomous snakes can cause significant health issues and even death around the world, though the exact total number of such bites isn’t known. In the U.S., between 7,000 and 8,000 venomous snake bites are reported each year, resulting in around 5 to 10 deaths. However, the true numbers may be higher as reporting of snakebites isn’t mandatory. Interestingly, bee stings result in more deaths in the U.S. than snake bites.
People who have been bitten by a venomous snake might show signs such as puncture wounds, localized pain and swelling, feeling sick, throwing up, muscle spasms, dizziness, and numbness or a tingling feeling around the mouth. They might also have trouble breathing, have a dangerously high or low blood clotting ability and could experience shock – a serious condition that often occurs suddenly in reaction to a severe injury or illness. Things often done before arriving at the hospital, like putting on ice, drinking alcohol, cutting the wound, or trying to suck out the venom, aren’t recommended. Resting the bitten limb, also known as immobilization, is usually the first advisable step.
In North America, using tourniquets around the bitten area isn’t suggested, as they are for only those snake venoms which have severe nerve-damaging effects. It’s beneficial to keep the person calm and encourage them to drink fluids before quickly getting them to an emergency center. Once there, the healthcare team will conduct tests to check for abnormalities in the blood, nervous system, kidney function, and heart health. The main treatment for venomous snakebites is a medication which neutralizes the venom, called antivenom. The specific type of antivenom required depends on the type of snake. The older type of antivenom made from horse serum has now been mostly replaced by safer versions made from sheep serum or a different version of horse serum.
What Causes Snake Toxicity?
Bites from venomous snakes usually happen when humans startle or corner these creatures, especially a type of snake known as pit vipers. With more people enjoying outdoor activities like hiking, backpacking, and fishing in warm weather, along with the growing trend of keeping venomous snakes as pets, there has been an increase in snakebites over recent years.
However, not all snakebites inject venom into the body. It can be challenging at first to tell whether a snakebite has injected venom or not.
Risk Factors and Frequency for Snake Toxicity
There are roughly 3,000 types of snakes all over the world, and 10% to 15% of them have venom. They mainly use their venom to capture their prey.
In the United States, over 95% of snake bites come from the Crotalidae family, also known as “pit vipers”. These snakes have special heat-sensitive “pits” between their eyes and nostrils to find their prey. This group of snakes includes:
- Rattlesnakes, from the Crotalus and Sistrurus genera
- Copperheads, also known as Agkistrodon contortrix
- Cottonmouths, or water moccasins, called Agkistrodon piscivorous
Another type of venomous snake, the Elapidae or coral snakes, cause much fewer snake bites in the United States. They are mostly seen along the southern edge of the United States, while pit vipers are spread throughout the majority of the country.
Rattlesnakes are the ones usually causing snakebite-related deaths in people and pets in the U.S. Most of the coral snake bites happen in southern states such as Florida, Texas, North Carolina, and Georgia.
People at greater risk of snake bites are often males, those who handle or disturb a snake, and owners of venomous snakes.
Signs and Symptoms of Snake Toxicity
A check-up focusing on your health history and current condition is essential if you have been bitten by a snake. The initial evaluation involves checking your breathing and blood circulation. Close monitoring is necessary given the risk of developing shock or respiratory failure after a snakebite. Knowing the exact time of the snakebite, any immediate aid given, and your existing medical conditions, such as heart, lung or kidney diseases, can be critical information. Additionally, facts about any allergies you may have, and when you last received a tetanus shot, can be important details. Examining and tracking any changes in the bite area is important too. If the site of the snakebite gets increasingly reddened, swollen, or forms blisters, it could be a sign that your condition is getting worse. Identifying the snake can be helpful for treatment, but only if it can be done safely. You shouldn’t try to capture or kill the snake as it could be dangerous. An ultrasound can also be used to determine the severity of the bite.
Testing for Snake Toxicity
If you or your doctor suspects you’ve been bitten by a venomous snake, there are several key tests that you’ll go through. This initial evaluation is designed to gather information about your health condition and understand the severity of the snakebite.
First, they’ll check your routine vital signs. These include your heart rate, blood pressure, body temperature, and breathing rate. This helps to monitor your overall health condition after the bite.
Next, they’ll likely do an Electrocardiogram (ECG), which checks how your heart is functioning, and keep you on continuous cardiac monitoring. This is important as snake venom can affect the heart.
Then, you’ll probably get a Complete Blood Count (CBC). This tests the number of different types of cells like red blood cells, white blood cells, and platelets are in your blood. It gives a picture of your general health and can show if your body is fighting an infection or another problem caused by the snakebite.
You’ll also do a urinalysis (UA), which tests your urine for various substances. Some venoms can affect kidney function, so this test can help show if there’s been any damage.
Prothrombin time (PT) and Partial thromboplastin time (PTT) tests show how long it takes for your blood to clot. Some snake venoms can cause blood clotting problems, so these tests can give information about this.
Fibrinogen is a protein in your blood that helps it clot. You’ll have this level checked, as some snakebites can cause your fibrinogen level to drop.
You will likely also have a complete metabolic panel done. This series of tests measures various chemicals in your blood, including blood urea nitrogen and creatinine, which provide information about how your kidneys are working.
Lastly, they’ll check your blood type and possibly prepare 2-4 units of red blood cells just in case you need a blood transfusion later. This readiness can prove crucial in a severe snakebite case.
All of these tests will help your doctor better understand the effects of the snakebite and plan the best treatment for you.
Treatment Options for Snake Toxicity
If you are bitten by a snake, it is crucial to get immediate medical attention. Before arriving at the hospital, there are some steps you can take to help manage the situation. These include moving away from the snake, calming down, trying not to move the affected area if possible, cleaning the wound, looking for changes in the skin around the wound, and drinking clear fluids if you are able to. If possible, try to identify the type of snake but only if it doesn’t pose a risk of more injury. Do not try to cut the wound or suck out the venom; also avoid applying ice to the wound or drinking alcohol.
Once at the hospital, the doctors will focus on a couple of key steps to manage the situation. This might involve giving you an intravenous fluid, determining how severe the snake bite is and whether you need anti-venom, cleaning the wound, and observing you for 12 to 24 hours or more. If the venom has led to a condition called compartment syndrome, which is a painful condition caused by pressure buildup from internal bleeding or swelling of tissues, they may need to discuss whether surgery is needed. They might also give you a tetanus shot if needed.
The severity of a snake bite can vary greatly, ranging from mild symptoms to severe effects. Severe cases can include swelling, formation of blisters or dead tissue, and symptoms like weakness, nausea, vomiting, muscle cramping, and convulsions. Mild cases might just cause some redness and swelling around the bite without other signs of venom in the body. Whether you will need to receive anti-venom and how much will largely depend on how severe the venom is affecting your body.
The doctors have two types of antivenoms they might use, one is derived from sheep and the other from horses. Both work by neutralizing the venom in your body. The one derived from sheep is smaller in size and can therefore penetrate tissue, but it also gets cleared out of the body faster, so repeated dosing is often needed. The one derived from horses is larger in size and remains in the body for longer; therefore, repeated dosing is usually not necessary. Remember, the kind of antivenom you will get depends on your specific condition and any potential allergies you may have.
Severe snake bites are rare but if it happens, more of either antivenom may be needed. After receiving an antivenom, doctors might need to monitor some aspects of your blood health for a period. Those who have an allergy to sheep protein should only get the antivenom derived from horses, and those allergic to horse protein should receive the one derived from sheep.
What else can Snake Toxicity be?
If someone gets bitten by a snake, it may not always be a venomous one. So, it becomes important to consider and rule out other possibilities. When diagnosing a venomous snakebite, doctors also have to consider other causes that may show similar signs. These include:
- Bites from non-venomous snakes
- Bites from spiders
- Bites from ticks
- Bites from scorpions
- Stings from insects like bees, wasps, and ants (Hymenoptera)
- Infections of the soft tissue (for example, folliculitis or furuncles, which are types of skin infections)
What to expect with Snake Toxicity
If quick treatment is provided, most people who are bitten by venomous snakes in the United States have a good chance of recovery. Surprisingly, about one out of four bites from venomous snakes don’t even cause any venom to enter the body. Although there are several thousand venomous snakebites in America each year, typically fewer than 10 people die from them. Usually, these deaths occur in people who wait too long to get treatment or avoid it altogether.
Possible Complications When Diagnosed with Snake Toxicity
Snakebites from venomous snakes can lead to dangerous health issues like:
- Coagulopathy – a condition where the blood’s ability to clot is impaired
- Shock – a severe drop in blood pressure that prevents the body from getting enough blood flow
- Respiratory failure – a condition where the lungs can’t provide the body with enough oxygen
- Acute renal failure – a serious condition where the kidneys suddenly stop working properly
- Local skin infection – infection at the site of the snakebite
- Compartment syndrome – increased pressure in a muscle compartment that can damage muscles and nerves
- Serum sickness – an allergic reaction to certain medications or snake antivenin
Preventing Snake Toxicity
The main way to avoid snakebites from venomous snakes is to be cautious in places where snakes are found naturally, and to avoid owning or dealing with poisonous snakes at home.
The Centers for Disease Control and Prevention (CDC), which is a national organization that promotes public health, suggests wearing long pants and boots if you’re working or walking outdoors in areas where snakes are known to live. They also recommend wearing leather gloves when you’re handling bushes or reaching into places where snakes might be hiding. Wearing leather chaps or snake gaiters, which are protective coverings for your legs, can also be a good idea to protect you from snakebites.
The CDC strongly advises against handling any venomous snakes. For those who already own venomous snakes, it’s very important to be extra careful when handling them and to use secure enclosures to prevent them from escaping.
