THE STAR (Petaling Jaya, Malaysia) 09 April 06 Yikes, snakebites! (Dr Ylm)
There are three main types of poisonous snakes in Malaysia: the cobra, the viper and the sea snake. If you are bitten, each produces different symptoms due to the toxins in the venom released.
Snakebites are not as common in Malaysia as they are in other parts of Asia or Africa where a large number of rural people don’t wear protective footwear. Most snakebites occur on the hands and arms or legs and feet.
Are all cobra bites fatal?
Not every cobra’s bite will result in the release of venom. There is a study that shows that the percentage of “blank” cobra bites may be quite high, as much as 45% out of all cases in Malaysia. Snake charmers in India too are frequently bitten by their cobras, and in one study, it was shown that one out of three snake charmers bitten by king cobras had no signs of envenomation.
A cobra can do two things to make the victim suffer: 1) bite you; or 2) eject jets of venom towards you, usually at your eyes, as far as from 3m. This is called spitting.
A cobra’s venom contains neurotoxin. When a cobra bites you, the cells in the area bitten will die and degenerate (necrosis.) Sometimes, this may be the only sign you have been bitten by a cobra, and this usually appears within 48 hours of the bite.
I have heard a cobra’s bite can paralyse a person within minutes. Is this true?
There is immediate pain in the area around the bite. The skin darkens and there may be blistering. There is a characteristic putrid smell.
The rest of the symptoms and signs that can happen will vary from one person to the next. Sometimes they can happen in a matter of minutes, or even hours. Sometimes, it takes days. In others, nothing happens at all!
After the bite, the area might swell progressively. If the venom containing neurotoxin has entered your blood stream, you may experience drowsiness, nausea, vomiting, salivation. Sometimes you may even feel euphoric!
What is happening is that your entire neurological system may be affected. The first symptom that this is happening is that you may feel an inability to keep your eyes open.
Your diaphragm and chest muscle nerves may be affected, causing you to have shortness of breath and respiratory paralysis, which may lead to death in 24 hours, or a matter of minutes. Your entire body may become paralysed. You can’t speak or breathe and there may be frothing around your mouth.
What about a viper? I’m not sure I can recognise a viper. Are their bites the same as a cobra’s?
Some of the most famous snakes belong to the viper family – rattlesnakes, cottonheads, cottonmouths, etc. These are common in North America. The viper family have long fangs that are normally folded up against the upper jaw. When the viper strikes, the fangs stand erect.
There are two groups of vipers: 1) typical vipers; and 2) pit vipers. The pit vipers have a special sensory organ between their nostril and eye (a pit) to detect their prey. That’s why they are called “pit” vipers, and it’s not because of where they are found!
The viper’s toxin is haematoxic, which means it affects the circulatory (blood) system. There is intense pain and swelling at the bite site, which often will ooze with blood.
Then the toxin spreads in the body and begins to affect the clotting factors. Bleeding is a key sign – you may bleed from your mouth, nose, anus, under your skin. This toxin spreads more slowly than the cobra’s neurotoxin because it damages the blood vessels as it goes along, thus limiting its rate of spread.
At the end stage, there may be blood vessel collapse, which may manifest as cold skin, a rapid and feeble pulse, and a gradual loss of consciousness.
Is a sea snake dangerous? They look so harmless. How will I be able to differentiate them from eels?
They are far from harmless! Sea snakes have vertically flattened tails and nostrils with valve-like flaps. Unlike eels, they do not have gills or fins (they are not fish). They must surface periodically to breathe. They generally are not aggressive, and will only bite you if you provoke them.
Nearly 80% of sea snake bites do not produce venom. And unlike the cobra or viper, their bites may be painless and free from swelling. You might not even think you have been bitten.
Nevertheless, the sea snake venom is extremely potent, and contains neurotoxins and myotoxins. The neurotoxins can paralyse a person, just like a cobra. The myotoxins cause your muscles to die and degenerate (necrosis), thus breaking them down and releasing myoglobin and potassium into your bloodstream.
The predominant symptoms are neurologic, like the cobra’s, and may occur as early as five minutes or as late as eight hours. There may be a change in your urine colour to reddish brown due to the myoglobins present in your urine. Your heart may actually stop or go into irregular rhythms due to the increased level of potassium in your blood.
What can I do if I have a snake bite?
Keep calm and restrict your movement to keep down the venom flow into your blood. Take off your rings, watches, bracelets to allow swelling. Splint the bitten area if you can to restrict movement. Try to keep the bitten area below the level of your heart.
Seek medical help immediately because you will need anti-venom. Do NOT apply a tourniquet, cold compress or try to suck the venom out by mouth. Do not attempt to excise the bite with a knife. In short, many snakebite first aid procedures you see on TV are wrong.
Yikes, snakebites!