Venomous and non venomus snakes

Most of the world's snakes are what are referred to as clinically non-venomous. This means they do not produce a toxin that is clinically significant to people.

1. Venomous and Non Venomous Snakes

2. Snakes and their General Characteristics Classification of Venomous Snakes Venomous snakes in Pakistan (big four) Venom, its Chemistry, Composition, Venom Apparatus Types of Venom Post bite Management Mortality Ration around the World and in Pakistan Facts about Snakes Contents

3. Snakes are elongate, legless carnivorous reptiles. Total number of species(2700, 15%) Habitat(every continent) Skeleton and organs Molting(3-6 times, vulnerability) Burrows(only few) Senses(braille, lack of hearing) Feeding habits(All snakes are carnivores and eat live pray) Snakes & their Characteristics

4. Identification of venomous and non venomous snakes

5. Elapidae Kraits, Cobras Small head, short and fixed fangs . Viperdae Viper snakes Large, flattened triangular head, large grooved fangs Crotalidae Rattlesnakes Produce rattling sound Colubridae Tree snakes Short grooved fangs Hydrophidae Sea snakes Nostrils dorsally on head, flattened tail. Venomous snakes around the world

6. 74 species of snakes exist in Pakistan. 60 are terrestrial(13 venomous), 14 species aquatic. Big four -four venomous snake species responsible for causing the most snake bite cases in South Asia Venomous Snakes in Pakistan

7. Also called “naag” or “pala” Found in Pakistan, India, America, Indonesia, Africa, Philippines and few Arab countries. 1.Indian cobra  ( Raja naga )

8. 2.Common krait ( Bungarus caeruleus ) 3.Russell's viper  ( Daboia russelii )

9. also called as ‘ lundi ’ in Pakistan. Found in Pakistan, Sri lanka , India and some regions of Africa. 4.Saw-scaled viper  ( Echis carinatus )

10. Copper head which is called as ‘ kurad ’, Royal snake found in Pakistan, called as ‘ combhoria . Earth boa also called ‘ ba mui ’ in Balochistan Python also called ‘ azdaha ’ in Pakistan. These are found in Pakistan, India, China, and other Southeast Asian countries Some other venomous snakes

11. Snake venom is the poisonous, typically yellow fluid stored in the modified salivary glands of venomous snakes. There are hundreds of venomous snake species that rely on the venom they produce to attack and immobilize their prey. Snake venom

12. Contains more than 20 different compounds including mostly proteins and polypeptides. Snake venom is acidic and water soluble. On drying, it forms fine needle like crystals. Proteolytic enzymes : denature proteins Collagenase :degrades collagen Phospholipases A and B: breaks lipids Acetylcholinesterase:breaks acetate ester, in synapse Anticoagulants : prevents blood clotting hyaluronidase : rapid venom diffusion Composition &Chemistry

13. Venom glands present at each side of skull, behind the eyes. Venom Glands Muscles Ducts Fangs Venom delivery

14. Venom is mainly delivered by fangs. pierce tissue and allow venom to flow into the wound. Fangs-connected to sacs, folding, regrow Production of antivenom by milking from snakes Procedure of delivery Venom Apparatus- fangs:

15. Destroys red blood cells- hemolysis Disrupts blood clotting Cause tissue death and organ damage Accumulation of dead RBCs disrupts proper kidney function. Heart failure Viperidae produce hemotoxin Loss of body part Types of venom 1. Hemotoxic venom

16. Nausea Disorientation, Headache. Tissue swelling Internal bleeding Thirst Death Symptoms include:

17. Affects the nerves and nervous system. Disrupt chemical signals (neurotransmitters) Reduce or block reception sites of neurotransmitter Muscle paralysis Respiratory difficulty Elapidae produce neurotoxic venom cobras, sea snakes, coral snakes Neurotoxic Venom

18. Calciseptine : voltage-gated calcium channels, black mambas Cobrotoxin : blocks nicotinic acetylcholine receptors, by cobras Calcicludine : calcium channels by green mamba Fasciculin -I: inhibits AChE cause uncontrollable muscle  movement, convulsions, and breathing paralysis by green mamba Calliotoxin : targets sodium channels causing paralysis by blue coral snakes Examples of snake neurotoxins include:

19. Ptosis (Droopy eyelids) Seeing double, Sleepy, paralysis, Respiratory failure. Salivation Vomiting Death can occur SYMPTOMS

20. They attack and kill living cells of all sorts. Destroy cells by damaging the cell membrane and inducing cell lysis . Observable tissue damage at site of bite Necrosis Cardiotoxins Myotoxins Nephrotoxins Cytotoxic Venom

21. intense local pain gradual swelling Nausea Vomiting loss of conciousnessness

22. FEATURES OF POISONOUS BITE: Swelling, blistering or necrosis at the site of the bite Hypotension Haemorrhage -blood loss from blood vessel Laboratory evidence of coagulation defect Arrhythmias Myoglobinuria -presence of myoglobin in the urine due to muscle destruction Post Bite Management

23. Remove the patient from the snake's territory in order to avoid further harm. Remove any jewelry or constricting clothing from the patient's affected area. In the immediate setting, withhold all alcohol and any drugs interfere with treatment. Do not incise the bite site or perform suction. The most urgent priority, is to take patient to a hospital where antivenin can be given Mark the extent of the redness and swelling with ink, indicating the date and time. Important considerations

24. Fang marks Pain Local swelling Local necrosis Local features of bitten area:

25. Flushing, breathlessness, palpitations, and dizziness, tightness in the chest, sweating are common. Early symptoms in elapid bites include vomiting, heaviness of eyelids, blurring of vision, hypersalivation , congested conjunctivae and ‘gooseflesh’. In krait bites, diarrhoea occur. Sea snake envenomation causes headache, a thick feeling of the tongue, thirst, sweating and vomiting. It is important to remember that nausea and vomiting are common symptoms of all severe envenomation . General features

26. Clotting defects and haemolysis . Persistent bleeding from fang puncture wounds and partially healed wounds suggest that the blood is incoagulable. Spontaneous systemic haemorrhage is most often detected. Viper and sea snake venoms also cause intravascular haemolysis . Systemic features

27. Eristostatin : extracted from Asian sand snake, helps people’s immune systems fight skin cancer. Contortrostatin : Stop the cancer cells from getting manufacturing signals, presently tested on animals till now. Hannalgesin : This drug is 20-200 times simpler than morphine and might even be taken orally. Hemotoxins : treatment of high BP,blood disorders,heart attack Neurotoxins: treatment of high blood pressure, blood disorders, and heart attack Venom and medicine

28. The first venom-based drug to be developed and approved by the FDA was captopril , derived from the Brazilian viper and used for the treatment of high blood pressure. Other drugs derived from venom include eptifibatide (rattlesnake) and tirofiban (African saw-scaled viper) for the treatment of heart attack and chest pain. Captopril

29. Epidemiology: incidences=30-40k

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31. Incidences in Pakistan: in Pakistan, snake bite is common in both agricultural areas and mountains of Balochistan . Snake bite is an acute public health problem in Sindh especially Thar . Favourable weather: In Pakistan, the peak incidences of snake bite occur in the month of june to august. This is because of: 1. Floods and rain. 2. Sleeping on open space 3. Hatching of cobra and krait in summer. Cont..

32. India has the biggest snake bite death toll, with around 11,000 lives lost. In total, between 1.2 million and 5.5 million snake bites may occur annually Studies suggested that only 8.5% of snake bite victims in Nigeria and 27% in Kenya sought hospital treatment. Southern Asia bore the brunt of the deaths. In this part of the world, venomous snakes such as cobras and vipers killed 14,000 people each year. Acc to scientists :The highest burden exists in South Asia, South-East Asia, and sub-Saharan Africa." Mortality Rate due to Snake Bite :

33. Snake’s scales are made of Keratin, same thing that our fingernails are made from. Mother Pythons coil themselves around their eggs and make their bodies shiver in order to heat herself up and keep her eggs warm until they hatch. The biggest snake is the Reticulated Python.  It can grow up to 10.05 meters or 33 feet long. The thickest snake is the Anaconda.  The biggest one found measured 44 inches around.  Facts

34. The Thread snake is the smallest snake.  It is only about 10 centimeters (4 inches long) and the size of a toothpick. Cobras are faster learners than other snakes. Can tell difference between their trainer and strangers. The Hognose, Grass snake and the Spitting Cobra will fake death when feeling threatened.  They flip into their backs, open their mouths, and let their tongue flop out.  And they will let out some smelly stuff from their anal gland. Cont..

35. Hansdak S.G. 1998. A clinico -epidemiological study of snake bite in Nepal. Pmed . 28:223-6. Pearn , J. 1981. First aid for snake bite. Efficacy of constrictive bandage with limb immobilization in the management of human envenomation . Med J Austral. 2:293-5. Theakston , R.D., D.A. Warrell , and E. Griffiths. 2003. Report of WHO workshop on the standardization and control of antivenoms . Toxicon . 41:541-57. THEAKSTON, R.D.G. and H.A. Reid. 1983. Development of simple standard assay procedures for the characterization of snake venom. Bulleton of the world health organization. 61:949-56. Thomas, P.P. and J. Jacob. 1985. Randomised trial of antivenom in snake envenomation with prolonged clotting time. Br Med J. 291:177-8. WHO. 2005. Regional Office for Southeast Asia. The clinical management of snake bites in the south East Region Asia. References:

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