From the Principal’s Desk


H.Miller 1

 

PRINGLE HOUSE ECO SCHOOL – SNAKE AWARENESS

Dear PHES Parents

At our last SGB meeting, a very valid point was raised: What procedures would we follow in the case of a snake bite on our property?

We do have two emergency contact numbers and would rush the patient to our nearest hospital. I have sent an email to a Mr. Arno Naude asking him for some feedback in this regard. Please read the following note that I have compiled which is very informative. I have included information of the snakes which appear on the RED LIST. We will obviously do our very best to educate our learners of the dangers of snakes and keep the immediate area around the school free from any overgrown plants. If you have anything further you could add to this, please email it to me and I will ensure it is shared.

Thanks to Arno Naude for an excellent and informative site on snakes.

Light and love

Heather Miller

Introduction

In the event that you or someone close to you gets bitten by a snake it does not mean that you will die, however this also should not be taken lightly either. All the advice columns will say don’t panic. That is rather difficult, panic but get over it quickly! According to statistics the chances that the bite will be life threatening is very slight however possibly being a negative statistic does not make anyone feel any better. Most of the snakes found in South Africa are not venomous and even the ones that are dangerously venomous are the minority as well. However in the event that someone has been bitten and given enough venom to be dangerous, the only solution to this is a suitable amount of the correct antivenom, administered within the correct timeline.

In South Africa we make one antivenom to counter the effects of the Boomslang and another antivenom to neutralise the effects of all Cobras, Mambas, Rinkhals and the two big adders namely the Puff adder and the Gaboon adder. In the event that effects of the venom indicate that it could become life threatening then the antivenom will counter this. The antivenom should preferably be administered in a hospital setup so that in the event that your body shows a massive allergic reaction to the antivenom then they can save your life.

Even being bitten by snake which possesses a potentially dangerous venom, does not mean you are going to have any ill effects or die. Snakes can bite and not give off any venom or just give off a small amount. In most snake bites you have a few hours before the effects become life threatening which is enough time to get to medical help. There is virtually no first aid that can save your life, it could slow down the effects in certain cases but it is not a cure. The pressure bandage method (link) does help however knowing which species of snake bit you, is very important. Tourniquets are also only advisable in Mamba and Cobra (excluding spitting cobras) bites as reducing the blood supply to an area where the tissue is being affected is the wrong thing to do.

Some look the same most of the time (Green and Black mambas) while others can be found in a variety of colours and patterns. Just remember that snakes are also known to “hitch hike” with loads of wood, plants and even just under vehicles so it is possible to find the snake far outside their distribution range.

 

RED LIST!

Boomslang

(Dispholidus typus)
DISTRIBUTION:
Throughout Southern Africa, except the Karoo, Namaqualand and Western Cape.

DESCRIPTION:
Adults average between 1,2m and 1,5m in length. It is a slender snake. Very large eyes.

COLOUR:
Juveniles: Light grey to brown above with fine blue spots anteriorly. The throat is yellow to orange in colour. The eyes are a brilliant green. Adult female: Light brown or olive above and cream to dirty white on the belly.
Adult male: Green to olive green above and light green below OR bright green, with the scales having a black edge, OR dark brown with bright yellow belly. Females will sometimes have typical male colouring.

Black Mamba

(Dendroaspis polylepis)
DISTRIBUTION:
Eastern Cape, Kwazulu-Natal, Transvaal, Mozambique, Zimbabwe, Botswana, Namibia, Zambia and Angola

DESCRIPTION:
Long and slender with a narrow head also described as coffin – shaped. Adults vary between 2,5m and 3m but they may reach a length of 4m.

COLOUR:
Juveniles are light grey to olive and darkening to gunmetal grey with age. The inside of the mouth is pitch black.

Green Mamba

(Dendroaspis angusticeps)
DISTRIBUTION:
Eastern Coastal area from Pondoland to northern Mozambique, Eastern Zimbabwe

DESCRIPTION:
Long and slender with a narrow head also described as coffin-shaped. Adults vary between 1,5 m and 2,5m

COLOUR:
Bright green above and yellowish green below

Cape Cobra

(Naja nivea)
DISTRIBUTION:
Cape, Free State, North West Province, Namibia, Lesotho and Southern Botswana.

DESCRIPTION:
Slender Cobra and smaller than the snouted cobra. Average 1,2m in length.

COLOUR:
Coloration is varied. May be either butter yellow or mottled yellow and brown or even uniform brown to black.

 

Puffadder

(Bitis arietans)
DISTRIBUTION:
Whole of Southern Africa

DESCRIPTION:
Head flattened and broad – [ Diamond shaped]. Body short and stocky. Adults average less than a metre.

COLOUR:
Shades of yellow-brown, and brown with darker brown to black chevron markings.

 

 Rinkhals

(Hemachatus haemachatus)
DISTRIBUTION:
Southern Cape, Transkei, Lesotho, Free State, Kwa-zulu Nata, Swaziland, Central and Southern Transvaal.

DESCRIPTION:
Sturdy snake with keeled scales. Length 1-1,5m

COLOUR:
Above: Dark brown or slate grey or dark black. Below: Same as above with two or three white bands on the throat.

 

There are different types of venom

Cytotoxic Venom

TISSUE AFFECTING TOXINS (CYTOTOXIC)

Major cytotoxic snakes include –
PUFF ADDERS, GABOON ADDERS, MOZAMBIQUE SPITTING COBRA, WESTERN BARRED SPITTING COBRA (Namibia), WOOD’S BLACK SPITTING COBRA.

Spitting Cobras have a Cytotoxic and to a lesser extent Neurotoxic venom.
Rinkhals in some areas have a strong cytotoxic effect as well.

Minor cytotoxic snakes include –
Stiletto snake (also known as the burrowing asp), Horned Adder and Many-horned Adder, Night Adder and Snouted Night Adder, Desert Mountain Adder and Plain Mountain Adder.

The venom and fangs: In the adder family, venom is injected most often just under the skin into subcutaneous tissue via hollow, movable fangs located in the anterior mouth although because of the size of the fangs intramuscular or intravenous injection also occurs. The cobras do not have movable fangs and these are much shorter so most bites are subcutaneous.

Cytotoxic venom is generally composed of several digestive enzymes and spreading factors, which result in local and systemic injury. Clinically, local effects progressing from pain and edema to ecchymosis (bleeds under the skin) and bullae (watery blisters) most commonly predominate. Hematological abnormalities including benign defibrination with or without thrombocytopenia (increased bleeding and decreased clotting) may result, but severe generalized bleeding is not common.

Pain and swelling occurs almost immediately after the bite from a cytotoxic snake and gradually becomes worse, in the next few hours. (Within 4 to 6 hours it will be more pronounced) It is often described as “cold fire” Later shock develops and this may cause death.

Findings of necrosis usually are evident by 48 hours following the bite. Necrosis begins with darkening of the area around the fang punctures. Blistering may follow. Necrosis usually is confined to the skin and subcutaneous tissue, but may be quite extensive. A putrid smell is characteristic.

Acute inflammation of the eye follows venom-spitting exposure and is characterized by ocular congestion, edema of the conjunctiva and cornea, and a whitish discharge.

Haemotoxic Venom

BLOOD TOXINS (HAEMOTOXIC)

Major haemotoxic snakes include –
BOOMSLANG, BIRD or TWIG SNAKE.

SYMPTOMS.

This type of venom is slow in comparison with the other two types mentioned. Effects can be seen after as little as 1 hour but can take a few days to manifest. The venom causes irregularities in the victim’s blood, preventing it from clotting. A bleeding tendency occurs starting with all the mucous membranes and progress to nose bleeds, bruises, blood is found in the urine and vomiting of blood. Anaemia and shock may develop and eventually kidney failure may set in. Slight pain and discomfort and haemorrhage at sight of bite, dizziness and headaches are known to occur.

Fibrin degradation products are cleared through the kidney and secondary renal failure is a potential complication of coagulopathy.

Death usually follows after 2 to 5 days. Antivenom can be administered after a few days and still work effectively however the kidneys would have been damaged by then. In the event that the antivenom is not obtained in time, whole blood and fresh freeze-dried plasma should be administered

Neurotoxic Venom

NERVE AFFECTING TOXINS (NEUROTOXIC)

Major neurotoxic snakes include –
BLACK MAMBA, GREEN MAMBA, CAPE COBRA, FOREST COBRA, SNOUTED COBRA (formerly known as Egyptian Cobra), RINKHALS, SEA SNAKES.

Rinkhals have a Cytotoxic as well as a Neurotoxic venom.

Minor neurotoxic snakes include –
Coral Snakes, Shield Nose Snakes, Garter Snakes, Berg adders (generally do not cause respiratory distress).

The Elapid group: To many people, the cobras and mambas are the quintessential venomous snake. Most of these snakes elevate the head and spread the neck as a threat gesture. However, a number of other snakes, venomous and non-venomous, employ this defense as well. However when encountered, cobras and mambas usually try to escape, but occasionally defend themselves boldly and may appear aggressive.

The venom: Non spitting cobra and mamba envenomation is an extremely variable process. Most species cause profound neurological abnormalities (eg, cranial nerve dysfunction, abnormal mental status, muscle weakness, paralysis, and respiratory arrest).

Mortality/Morbidity:

It is difficult to determine the exact cobra and mamba contribution to overall snakebite morbidity and mortality. In most cases, bitten individuals do not see the snake well enough to identify it.

Mamba bites are considered more serious than bites from other elapid species. This is due to greater volumes of injected venom and more rapid onset of neurotoxic symptoms. Mortality is also higher.

Most snakebites are inflicted on body extremities. Since these snakes usually only bite when molested, bites on the hands and feet are common. Due to their size, bites to the head and torso is not uncommon with mambas.

If the snake is not on the red list above then it will probably not kill you. It is possible that some will give you a nasty bite which hurts or it can cause you to have an allergic reaction the same as you would from a bee sting. Some snakes have killed people however this has only ever happened once or twice so they are not used in the production of antivenom and thus using the SAVP antivenom will not be advisable or effective. They are listed under yellow tabs. The Black or Woods spitting cobra is expected to have a lethal venom and although the SAVP antivenom is not designed for this snake, judicious amounts of antivenom should be able to neutralise the lethal effects of the venom.

What to do if your child has been bitten

  • Look for marks to make sure that the child has been bitten.
  • If possible, find the snake and kill it for identification. Take it to the hospital or doctor when you take the child.
  • Always seek medical attention, preferably in the emergency department of your nearest hospital.
  • The most likely snake to have bitten your child is the puff adder since they are slow-moving. This is a fat, brown snake with a triangular head, with yellow stripes and spots on its body. For this type of bite, do not use a tourniquet. Antivenom is not usually needed unless the child is under the age of two, or they are a long way from hospital.
  • If you know that the bite is from a cobra or mamba, use a tourniquet. The child will need antivenom on arrival at hospital.
  • Cutting or sucking the wound, or using alternative remedies, are useless. Don’t do it.
  • If a snake spits into your child’s eyes, wash the eyes with large amounts of water, preferably by holding their head under a running tap. Do this before taking the child to hospital, since it will get rid of most of the poison. Once in hospital, the eyes will be washed further, often with diluted antivenom.

General first aid measures include lying the child down and immobilising the part of the body which has been bitten. Pressure should be applied at the site of the bite. A tourniquet should be placed above the bite if possible. You should be able to insert a finger gently between the tourniquet and the skin. You can use a belt, a broad strap, or the rubber tourniquet supplied with any snake-bite kit. It must be put on around the thigh or upper arm, above the bite.

A tourniquet can only be used for one and a half hours, during which time it must be released for a few seconds every 15 to 30 minutes. Do not use a tourniquet if:

  • The bite occurred more than an hour previously.
  • There is a large amount of local swelling or pain.
  • The child was bitten by a puff adder.

(Reviewed by Prof Don du Toit)

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