Snake Bite
Travelling to the Southern Province we find ourselves surrounded by agriculture and rural beauty. It is the home of Mosi-ao-Tunya (Victoria Falls) which Zambia shares with Zimbabwe. Formed by the Kariba Dam, Lake Kariba and the great Zambezi river run down the southern border of the province and in particular Siavonga district. Siavongo district lies at an elevation of 511m covering a land area of approximately 5,300 sq km. It had a population of 90,213 at the 2010 census but is likely to be in the region of 117,500 now. The town of Siavongo which houses the district hospital, is the principal tourism centre for the lake and is becoming known as the ‘Riviera of Zambia’. Travel approximately 100km from Siavonga and you arrive at Chaanga rural health centre where this month’s case arrived to be seen.
Southern Province. Siavongo is shown in pale blue on the eastern most corner
The Chaanga clinic
Virtual Doctors support 4 rural health centre throughout Siavongo district as well as the Siavongo district health team in the district hospital.
Clinical Officers training in Siavonga
Chaanga clinic was busy through February 2017. At the very start of the month the clinical officer saw a 9 year old boy who was brought in having had a snake bite to his leg. Two days after being bitten he had been taken to see a traditional healer and given some traditional treatment. Unfortunately this resulted in a large and infected wound. The Clinical Officer (CO) sent a patient file to the virtual doctors wanting to know how best to treat this. Examination revealed no loss in sensation to the affected area but a large infected wound.
The snake bite wound
The Virtual Doctors advice was to treat this wound like a burn. The wound was to be kept clean and dressed every 48 hours until granulation (healing) was seen. Antibiotics and pain relief was also recommended; antibiotics to be continued until the wound was fully healed. It is very important to prevent and treat infection to avoid further complications such as abscess formation or bone infection (osteomyelitis). These complications can result in amputation of the limb or to an overwhelming infection (sepsis) which can, if untreated, lead to death. Due to the nature of the wound it is likely this was a puff adder bite. This I will explain further below.
Fortunately in this case the patient was seen early receiving the right treatment and the CO was grateful for the advice, avoiding sending the patient to hospital and enabling him to be confident in managing this and future wounds.
Snakes in Zambia
There are many snakes in Zambia, most are harmless with just a few being venomous. Fortunately most venomous snakes will often avoid humans and get out of the way when they feel the vibrations of your footsteps. If they do bite, they rarely inject their full venom load. Generally they only strike when they are surprised, cornered or threatened. The danger from snake bites and the toxicity of venom varies from species to species.
The most deadly snakes found in Zambia are:
African rock python- the largest snake in Africa, non-venomous common in rural areas reaching up to a 6m or more in length. It kills prey by constricting them.
Black Mamba- the longest venomous snake in Africa- up to 4.5m long. It is said by some to be the fastest snake in the world, able to travel at 20km/h! Its venom is neurotoxic.
Black- necked spitting cobra- quite common, sprays venom when cornered. Its venom is neurotoxic. Cover your eyes as theses snakes are short sighted and will spit at anything that glints!
Puff Adder –common venomous snake. It is thought to be responsible for most bites to humans as it is well camouflaged, remains motionless and bites when unwittingly stepped on. The venom is cytotoxic.
Boomslang- a common green tree snake, venomous but timid. They produce a haemotoxic venom. Boomslang bites are rare as these snakes are back fanged.
Gaboon Viper- the largest viper. It is found in woodland, savanna and forests in the north of Zambia. Their venom is haemotoxic. They also have the longest fangs of any snake-each one almost as long as an adult’s little finger! They are rare.
Different kinds of Venom
Of these beautiful snakes above, the majority produce venom. Each venom has its own toxic effects.
The mambas and cobras neurotoxic venom attacks the central nervous system. The bite feels like a sting. It attacks the nerves, causing difficulty in movement, in breathing, swallowing and slurred speech and can cause death due to breathing difficulty.
The boomslang and Gaboon Viper produce haemotoxic venom which prevents the blood from clotting leading to extensive blood loss into the tissues. The bite is generally not too painful but within an hour bleeding starts from the bite and any other wounds or scratches the victim may have. Other symptoms can include a severe headache, nausea and vomiting.
The puff adder produces cytotoxic venom which attacks the body’s cells. The bite is instantly painful with immediate swelling, bruising and blistering. It can lead to break down of tissues over a wide area. Symptoms can include nausea and dizziness. It is likely our patient was bitten by a puff adder.
What to do about Snake bites
Anyone bitten by a poisonous snake must get professional treatment as quickly as possible. Symptoms usually show themselves fairly soon after a bite so observing the victim is very important.
First aid: Do not panic. The vast majority of snakes are not venomous and in the rare event of being bitten by a venomous snake most will not inject their full venom load.
Keep the victim calm and still, movement only increases blood flow and transporting of the venom more quickly.
Loosen the victims clothing and keep them shaded.
Immobilise the limb but do not restrict blood flow.
Clean the wound with plain water and dress the wound with a bandage but being careful not to apply pressure and cause bruising.
Be prepared to administer CPR if necessary.
If possible try to identify the snake, taking a photo as long as no one else puts themselves in danger. Pictures are useful for medical identification. Useful things to note are colour, size, shape of head and attacking method.
What NOT to do when a snake bites:
The advice for bites varies but the consensus about what not to do is pretty consistent:
Never use a tourniquet which cuts off the blood flow for this purpose.
Do not allow the victim to exercise or stress themselves
Do not cut or bite or attempt to suck the venom out.
Do not use potassium permanganate crystals or solutions near or on the bite wound nor use soapy water around the wound. Do not put ice or heat on the wound.
Do not leave the victim alone.
And finally it is worth remembering fatalities from bites are quite rare. When in the bush be careful and keep a look out. The more noise you make when walking the more chance the snake has to move off. Wear boots and long trousers. And remember shake your boots before putting them on!
Disclaimer: This article is for information only and shouldn’t be used for diagnosis or treatment of medical conditions. If you have any concerns about your health consult a doctor or other health professional.