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92-480: After an intense seasonal thunderstorm, an Indian mongoose named Rikki-Tikki-Tavi (from his chattering vocalizations) becomes the pet of an English family residing in India after they save him from drowning. He becomes friendly with some other creatures inhabiting their garden. However, the cobras , named Nag (the male) and Nagaina (the female), are angered by the human family's presence in their territory and fear Rikki as

184-409: A blood alcohol level of 0.1 percent or more. It is also important to avoid snakes that appear to be dead , as some species will actually roll over on their backs and stick out their tongue to fool potential threats. A snake's detached head can immediately act by reflex and potentially bite. The induced bite can be just as severe as that of a live snake. As a dead snake is incapable of regulating

276-461: A combination of many toxins, including cytotoxins , hemotoxins , neurotoxins , and myotoxins , allowing for an enormous variety of symptoms. Snake venom may cause cytotoxicity as various enzymes including hyaluronidases , collagenases , proteinases and phospholipases lead to breakdown (dermonecrosis) and injury of local tissue and inflammation which leads to pain, edema and blister formation. Metalloproteinases further lead to breakdown of

368-476: A flaccid paralysis that is descending; starting at the facial muscles, causing ptosis or drooping eyelids and dysarthria or poor articulation of speech, and descending to the respiratory muscles causing respiratory compromise. The neurotoxins can either bind to and block membrane receptors at the post-synaptic neurons or they can be taken up into the pre-synaptic neuron cells and impair neurotransmitter release. Venom toxins that are taken up intra-cellularly, into

460-683: A geographic shift in risk of snakebite: northwards in North America and southwards in South America and in Mozambique, and increase in incidence of bite in Sri Lanka. Most snakebites are caused by non-venomous snakes. Of the roughly 3,000 known species of snake found worldwide, only 15% are considered dangerous to humans. Snakes are found on every continent except Antarctica . The most diverse and widely distributed snake family,

552-490: A method of hunting, and as a means of protection. Risk factors for bites include working outside with one's hands such as in farming , forestry , and construction. Snakes commonly involved in envenomations include elapids (such as kraits , cobras and mambas ), vipers , and sea snakes . The majority of snake species do not have venom and kill their prey by constriction (squeezing them). Venomous snakes can be found on every continent except Antarctica . Determining

644-525: A person may bleed spontaneously from the mouth, nose, and even old, seemingly healed wounds. Internal organs may bleed, including the brain and intestines, and ecchymosis (bruising) of the skin is often seen. The venom of elapids, including sea snakes , kraits , cobras , king cobra , mambas , and many Australian species, contains toxins which attack the nervous system, causing neurotoxicity . The person may present with strange disturbances to their vision, including blurriness. Paresthesia throughout

736-470: A person. Snakes may deliver such a " dry bite " rather than waste their venom on a creature too large for them to eat, a behaviour called venom metering . However, the percentage of dry bites varies among species: 80 percent of bites inflicted by sea snakes , which are normally timid, do not result in envenomation, whereas for pit viper bites the number is closer to 25 percent. Furthermore, some snake genera , such as rattlesnakes , can internally regulate

828-424: A pile and are bitten. Most however occur when people handle rattlesnakes. In South Asia, it was previously believed that Indian cobras , common kraits , Russell's viper , and carpet vipers were the most dangerous; other snakes, however, may also cause significant problems in this area of the world. Since envenomation is completely voluntary, all venomous snakes are capable of biting without injecting venom into

920-409: A result. Furthermore, the death toll of such an injury could range between 80,000 and 130,000 people per year. The purpose was to encourage research, expand accessibility of antivenoms, and improve snakebite management in " developing countries ". Prevention of snake bites can involve wearing protective footwear, avoiding areas where snakes live, and not handling snakes. Treatment partly depends on

1012-536: A second person bitten, and generally is not recommended. The three types of venomous snakes that cause the majority of major clinical problems are vipers , kraits , and cobras . Knowledge of what species are present locally can be crucial, as is knowledge of typical signs and symptoms of envenomation by each type of snake. A scoring system can be used to try to determine the biting snake based on clinical features, but these scoring systems are extremely specific to particular geographical areas and might be compromised by

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1104-602: A snake is near. Since most venomous snakes move about during the dawn dusk or night, one may expect more encounters during the early morning or late afternoon, though many species such as the Western Diamondback may be encountered at any time of day and in fact most bites occur during the month of April when both snakes and humans are out and about and encounter one another hiking, in yards, or on pathways. Children playing within short distances of their homes crawl under porches, jump into bushes, pull boards of wood from

1196-422: A threat when they meet him for the first time. Scared at first, Rikki soon learns that a mongoose's quest is to track down and slay any snake he or she can find, and fends them off after a short skirmish. That same day, a young dust-brown snake named Karait threatens to bite the family's child, Teddy. This infuriates Rikki into challenging Karait, unaware the smaller snake is as venomous as a cobra and faster. Despite

1288-443: A vase in the darkness. The ensuing struggle awakens the family, and the father appears to kill Nag with a shotgun blast while Rikki bites down on the hood of the struggling male cobra. The following morning, a grieving Nagaina attempts revenge against the humans, cornering them as they have breakfast on a veranda. She is however distracted by the wife of Darzee the tailor bird (Darzee is singing about Nag's death) while Rikki destroys

1380-423: A wide range of habitats throughout its geographical range. It can be found in dense or open forests, plains , agricultural lands ( rice paddy fields , wheat crops), rocky terrain, wetlands, and it can even be found in heavily populated urban areas, such as villages and city outskirts, ranging from sea level to 2,000 metres (6,600 ft) in altitude. This species is absent from true desert regions. The Indian cobra

1472-453: Is a limited resource, larger animals are less susceptible to the effects of venom, and various situations require different levels of force. There is a lot of evidence to support the venom metering hypothesis. For example, snakes frequently use more venom during defensive strikes, administer more venom to larger prey, and are capable of dry biting. A dry bite is a bite from a venomous snake that results in very little or no venom expulsion, leaving

1564-539: Is a member of the "big four" species that are responsible for the most snakebite cases in India. It is distinct from the king cobra , which belongs to the monotypic genus Ophiophagus . The Indian cobra is revered in Hindu mythology and culture , and is often seen with snake charmers . It is a protected species under the Indian Wildlife Protection Act (1972). The generic name and

1656-1006: Is absent in most of Balochistan province , parts of Khyber Pakhtunkhwa Province , desert areas elsewhere and the Northern Areas . The most westerly record comes from Duki, Balochistan in Pakistan, while the most easterly record is from the Tangail District in Bangladesh. As this species has been observed in Drosh, in the Chitral Valley , it may also occur in the Kabul River Valley in extreme eastern Afghanistan . There's been at least one report of this species occurring in Bhutan . The Indian cobra inhabits

1748-588: Is advised not to reach blindly into hollow logs, flip over large rocks, and enter old cabins or other potential snake hiding-places. When rock climbing , it is not safe to grab ledges or crevices without examining them first, as snakes are cold-blooded and often sunbathe atop rock ledges. In the United States, more than 40 percent of people bitten by snakes intentionally put themselves in harm's way by attempting to capture wild snakes or by carelessly handling their dangerous pets—40 percent of that number had

1840-476: Is an occasional character who is a friend of Mowgli. The story was adapted as a picture book of the same name in 1997 by Jerry Pinkney . Indian cobra The Indian cobra ( Naja naja ), also known commonly as the spectacled cobra , Asian cobra , or binocellate cobra , is a species of cobra , a venomous snake in the family Elapidae . The species is native to the Indian subcontinent , and

1932-403: Is an overwhelming fear, which may contribute to other symptoms, and may include nausea and vomiting , diarrhea , vertigo , fainting , tachycardia , and cold, clammy skin. Snake bites can have a variety of different signs and symptoms depending on their species. Dry snakebites and those inflicted by a non-venomous species may still cause severe injury. The bite may become infected from

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2024-423: Is being developed. Earlier estimates for snakebite vary from 1.2 to 5.5 million, with 421,000 to 2.5 million being envenomings, and causing 20,000 to 125,000 deaths. More recent modelling estimates that in 2019, about 63,400 people died globally from snakebite, with 51,100 of these deaths happenning in India. Since reporting is not mandatory in much of the world, the data on the frequency of snakebites

2116-491: Is made by injecting a small amount of venom into an animal (usually a horse or sheep) to initiate an immune system response. The resulting antibodies are then harvested from the animal's blood. Antivenom is injected into the person intravenously , and works by binding to and neutralizing venom enzymes. It cannot undo damage already caused by venom, so antivenom treatment should be sought as soon as possible. Modern antivenoms are usually polyvalent, making them effective against

2208-565: Is not limited to non-healing and chronic ulcers, musculoskeletal disorders, amputations, chronic kidney disease, and other neurological and endocrine complications. The treatment of chronic complications of snakebite has not been well researched and there a systems approach consisting of a multi-component intervention. The following treatments, while once recommended, are considered of no use or harmful, including tourniquets, incisions, suction, application of cold, and application of electricity. Cases in which these treatments appear to work may be

2300-478: Is not precise. Many people who survive bites have permanent tissue damage caused by venom, leading to disability. Most snake envenomings and fatalities occur in South Asia , Southeast Asia , and sub-Saharan Africa , with India reporting the most snakebite deaths of any country. Available evidence on the effect of climate change on the epidemiology of snakebite is limited but it is expected that there will be

2392-487: Is not recommended for bites from non-neurotoxic snakes such as those found in North America and other regions of the world. The British military recommends pressure immobilization in all cases where the type of snake is unknown. The object of pressure immobilization is to contain venom within a bitten limb and prevent it from moving through the lymphatic system to the vital organs. This therapy has two components: pressure to prevent lymphatic drainage, and immobilization of

2484-422: Is often found in the vicinity of water. Preferred hiding locations are holes in embankments, tree hollows, termite mounds , rock piles and small mammal dens. Snakebite A snakebite is an injury caused by the bite of a snake, especially a venomous snake . A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs . Sometimes venom injection from

2576-486: Is often mistaken for the Indian cobra; however, this snake is much longer and can easily be distinguished by the more prominent ridged appearance of its body. Other snakes that resemble Naja naja are the banded racer Argyrogena fasciolata and the Indian smooth snake Wallophis brachyura . Also, the monocled cobra ( Naja kaouthia ) may be confused with Naja naja ; however, the monocled cobra has an O-shaped pattern on

2668-412: Is referred to by a number of local names deriving from the root of Naga. For Indo-Aryan and Dravidian languages: The Indian cobra is a moderately sized, heavy-bodied species. This cobra species can easily be identified by its relatively large and quite impressive hood, which it expands when threatened. Many specimens exhibit a hood mark. This hood mark is located at the rear ( dorsal surface) of

2760-480: Is relatively uncommon. The Indian cobra varies tremendously in colour and pattern throughout its range. The ventral scales or the underside colouration of this species can be grey, yellow, tan, brown, reddish or black. Dorsal scales of the Indian cobra may have a hood mark or colour patterns. The most common visible pattern is a posteriorly convex light band at the level of the 20th to 25th ventrals. Salt-and-pepper speckles, especially in adult specimens, are seen on

2852-428: Is snake species and size, larger snakes have been shown to administer larger quantities of venom. Snake bites are classified as either predatory or defensive in nature. During defensive strikes, the rate of venom expulsion and total volume of venom expelled is much greater than during predatory strikes. Defensive strikes can have 10 times as much venom volume expelled at 8.5 times the flow rate. This can be explained by

Rikki-Tikki-Tavi - Misplaced Pages Continue

2944-650: Is unknown, antivenom is often given based on the types known to be in the area. In some areas of the world, getting the right type of antivenom is difficult and this partly contributes to why they sometimes do not work. An additional issue is the cost of these medications. Antivenom has little effect on the area around the bite itself. Supporting the person's breathing is sometimes also required. The number of venomous snakebites that occur each year may be as high as five million. They result in about 2.5 million envenomations and 20,000 to 125,000 deaths. The frequency and severity of bites vary greatly among different parts of

3036-412: Is usually treatable in a hospital setting and hence the benefit outweighs the potential consequences of not using antivenom. Giving adrenaline (epinephrine) to prevent adverse reactions to antivenom before they occur might be reasonable in cases where they occur commonly. Antihistamines do not appear to provide any benefit in preventing adverse reactions. Chronic health effects of snakebite include but

3128-622: The Gaboon viper able to potentially deliver from 450 to 600 milligrams of venom in a single bite, the most of any snake. Opisthoglyphous colubrids have venom ranging from life-threatening (in the case of the boomslang ) to barely noticeable (as in Tantilla ). Snakes are most likely to bite when they feel threatened, are startled, are provoked, or when they have been cornered. Snakes are likely to approach residential areas when attracted by prey, such as rodents . Regular pest control can reduce

3220-399: The anal shield is single. There are seven upper labials (3rd the largest and in contact with the nasal anteriorly, 3rd and 4th in contact with the eye) and 9-10 lower labials (small angular cuneate scale present between 4th and 5th lower labial), as well as one preocular in contact with internasals, and three postoculars . Temporals are 2 + 3. The Oriental rat snake Ptyas mucosa

3312-498: The colubrids , has approximately 700 venomous species, but only five genera — boomslangs , twig snakes , keelback snakes , green snakes , and slender snakes —have caused human fatalities. Worldwide, snakebites occur most frequently in the summer season when snakes are active and humans are outdoors. Agricultural and tropical regions report more snakebites than anywhere else. In the United States, those bitten are typically male and between 17 and 27 years of age. Children and

3404-561: The kraits , coral snake , Mojave rattlesnake , and the speckled rattlesnake , may cause little or no pain, despite their serious and potentially life-threatening venom. Some people report experiencing a "rubbery", "minty", or "metallic" taste after being bitten by certain species of rattlesnake. Spitting cobras and rinkhalses can spit venom in a person's eyes. This results in immediate pain, ophthalmoparesis , and sometimes blindness . Some Australian elapids and most viper envenomations will cause coagulopathy , sometimes so severe that

3496-516: The specific epithet naja is a Latinisation of the Sanskrit word nāga ( नाग ) meaning "cobra". The Indian cobra is classified under the genus Naja of the family Elapidae . The genus was first described by Josephus Nicolaus Laurenti in 1768. The species Naja naja was first described by the Swedish physician, zoologist, and botanist Carl Linnaeus in 1758. The genus Naja

3588-1405: The 1990s, often as subspecies thereof. Many of the subspecies were later found to be artificial or composites. This causes much potential confusion when interpreting older literature. Naja ( Naja ) naja Naja ( Naja ) kaouthia Naja ( Naja ) atra Naja ( Naja ) sagittifera Naja ( Naja ) oxiana Naja ( Naja ) sputatrix Naja ( Naja ) samarensis Naja ( Naja ) philippinensis Naja ( Naja ) mandalayensis Naja ( Naja ) sumatrana Naja ( Naja ) siamensis Naja ( Afronaja ) pallida Naja ( Afronaja ) nubiae Naja ( Afronaja ) katiensis Naja ( Afronaja ) nigricollis Naja ( Afronaja ) ashei Naja ( Afronaja ) mossambica Naja ( Afronaja ) nigricincta Naja (Boulengerina) multifasciata Naja (Boulengerina) christyi Naja (Boulengerina) annulata Naja (Boulengerina) savannula Naja (Boulengerina) subfulva Naja (Boulengerina) guineensis Naja (Boulengerina) peroescobari Naja (Boulengerina) melanoleuca Naja ( Uraeus ) nivea Naja ( Uraeus ) senegalensis Naja ( Uraeus ) haje Naja ( Uraeus ) arabica Naja ( Uraeus ) annulifera Naja ( Uraeus ) anchietae The Indian cobra or spectacled cobra, being common in South Asia,

3680-585: The Indian cobra's hood. When the hood mark is present, it consists of two circular ocelli patterns connected by a curved line, evoking the image of spectacles . This species has a head that is elliptical, depressed, and very slightly distinct from the neck. The snout is short and rounded with large nostrils. The eyes are medium in size and the pupils are round. The majority of adult specimens range from 1 to 1.5 metres (3.3 to 4.9 ft) in length. Some specimens, particularly those from Sri Lanka, may grow to lengths of 2.1 to 2.2 metres (6.9 to 7.2 ft), but this

3772-577: The Middle East, it is carpet vipers and elapids . In Latin America , it is snakes of the Bothrops and Crotalus types, the latter including rattlesnakes . In North America, rattlesnakes are the primary concern, and up to 95% of all snakebite-related deaths in the United States are attributed to the western and eastern diamondback rattlesnakes. The greatest number of bites are inflicted on

Rikki-Tikki-Tavi - Misplaced Pages Continue

3864-486: The United States, with Orson Welles narrating and providing the voice of Nag. The same year, Aleksandr Juridic and Nan Nashville directed a live-action feature film entitled Rikki-Tikki-Tavi . In the anime television series , Jungle Book Shōnen Mowgli , Rikki-Tikki-Tavi is a supporting character who is the pet of an Indian family and is a heroic defender of them. In the CGI series The Jungle Book , Rikki-Tikki-Tavi

3956-511: The amount of venom they inject. There is a wide variance in the composition of venoms from one species of venomous snake to another. Some venoms may have their greatest effect on a victim's respiration or circulatory system. Others may damage or destroy tissues. This variance has imparted to the venom of each species a distinct chemistry. Sometimes antivenins have to be developed for individual species. For this reason standard therapeutic measures will not work in all cases. Some dry bites may also be

4048-600: The area. However, this generally only applies to vipers, as some larger and more aggressive snakes in other parts of the world, such as mambas and cobras , will respond more aggressively. If presented with a direct encounter, it is best to remain silent and motionless. If the snake has not yet fled, it is important to step away slowly and cautiously. The use of a flashlight when engaged in camping activities, such as gathering firewood at night, can be helpful. Snakes may also be unusually active during especially warm nights when ambient temperatures exceed 21 °C (70 °F). It

4140-458: The back of the hood, while the Indian cobra has a spectacles-shaped pattern on its hood. Confusions may exist with Caspian cobra ( Naja oxiana ), as some Indian cobra specimens without a hood mark are sometimes confused with N. oxiana , where these two species coexist in Pakistan and Afghanistan. Although some Caspian cobra specimens can be quite dark, they are never fully black like the Indian cobra. N. oxiana normally has several dark bands under

4232-448: The bite may occur. This may result in redness, swelling, and severe pain at the area, which may take up to an hour to appear. Vomiting , blurred vision, tingling of the limbs, and sweating may result. Most bites are on the hands, arms, or legs. Fear following a bite is common with symptoms of a racing heart and feeling faint . The venom may cause bleeding , kidney failure , a severe allergic reaction , tissue death around

4324-638: The bite, or breathing problems. Bites may result in the loss of a limb or other chronic problems or even death. The outcome depends on the type of snake, the area of the body bitten, the amount of snake venom injected, the general health of the person bitten and whether or not anti-venom serum has been administered by a doctor in a timely manner. Problems are often more severe in children than adults, due to their smaller size. Allergic reactions to snake venom can further complicate outcomes and can include anaphylaxis , requiring additional treatment and in some cases resulting in death. Snakes bite both as

4416-422: The bitten limb to prevent the pumping action of the skeletal muscles . Until the advent of antivenom , bites from some species of snake were almost universally fatal. Despite huge advances in emergency therapy, antivenom is often still the only effective treatment for envenomation. The first antivenom was developed in 1895 by French physician Albert Calmette for the treatment of Indian cobra bites. Antivenom

4508-411: The blood. These clotting factors normally work as part of the coagulation cascade in the blood to form blood clots and prevent hemorrhage. Toxins in snake venom (especially the venom of new world pit vipers (the family crotalina )) may also cause low platelets ( thrombocytopenia ) or altered platelet function also leading to bleeding. Snake venom is known to cause neuromuscular paralysis, usually as

4600-403: The body, a condition known as rhabdomyolysis . Rhabdomyolysis can result in damage to the kidneys as a result of myoglobin accumulation in the renal tubules. This, coupled with hypotension , can lead to acute kidney injury , and, if left untreated, eventually death. Snakebite is also known to cause depression and post-traumatic stress disorder in a high proportion of people who survive. In

4692-411: The body, as well as difficulty in speaking and breathing, may be reported. Nervous system problems will cause a huge array of symptoms, and those provided here are not exhaustive. If not treated immediately they may die from respiratory failure . Venom emitted from some types of cobras, almost all vipers and some sea snakes causes necrosis of muscle tissue. Muscle tissue will begin to die throughout

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4784-470: The cells of the pre-synaptic neurons are much more difficult to reverse using anti-venom as they are inaccessible to the anti-venom when they are intracellular. The strength of venom differs markedly between species and even more so between families, as measured by median lethal dose (LD 50 ) in mice. Subcutaneous LD 50 varies by over 140-fold within elapids and by more than 100-fold in vipers. The amount of venom produced also differs among species, with

4876-425: The cobra's unhatched brood of eggs, except for one. He carries it to the porch where Nagaina threatens to bite little Teddy while his parents watch helplessly. Rikki furiously challenges her and lures the cobra away from the family, giving the father enough time to grab Teddy away and keep him close. Rikki then reveals that it was he who put Nag down before the father opened fire on him. Nagaina recovers her egg during

4968-466: The developing world most snakebites occur in those who work outside such as farmers, hunters, and fishermen. They often happen when a person steps on the snake or approaches it too closely. In the United States and Europe snakebites most commonly occur in those who keep them as pets. The type of snake that most often delivers serious bites depends on the region of the world. In Africa, it is mambas , Egyptian cobras , puff adders , and carpet vipers . In

5060-474: The dorsal scales. Specimens, particularly those found in Sri Lanka, may exhibit poorly defined banding on the dorsum. Ontogenetic colour change is frequently observed in specimens in the northwestern parts of their geographic range (southern Pakistan and northwestern India). In southern Pakistan, juvenile specimens may be grey in colour and may or may not have a hood mark. Adults on the other hand are typically uniformly black in colour on top ( melanistic ), while

5152-420: The elderly are the most likely to die. When venomous snakes bite a target, they secrete venom through their venom delivery system. The venom delivery system generally consists of two venom glands, a compressor muscle, venom ducts, a fang sheath, and fangs . The primary and accessory venom glands store the venom quantities required during envenomation . The compressor muscle contracts during bites to increase

5244-451: The evidence base from majority of treatment modalities is low quality. An analysis of World Health Organization guidelines found that they are of low quality, with inadequate stakeholder involvement and poor methodological rigour. In addition, access to effective treatment modalities is a major challenge in some regions, particularly in most African countries. Identification of the snake is important in planning treatment in certain areas of

5336-471: The exception of specimens from the northwest, there is often a pair of lateral spots on the throat where the ventral and dorsal scales meet. The positioning of these spots varies, with northwestern specimens having the spots positioned more anterior, while specimens from elsewhere in their range are more posterior. Dorsal scales are smooth and strongly oblique. Midbody scales are in 23 rows (21–25), with 171–197 ventrals . There are 48–75 divided subcaudals and

5428-424: The extracellular matrix (releasing inflammatory mediators) and cause microvascular damage, leading to hemorrhage, skeletal muscle damage (necrosis), blistering and further dermonecrosis. The metalloproteinase release of the inflammatory mediators leads to pain, swelling and white blood cell ( leukocyte ) infiltration. The lymphatic system may be damaged by the various enzymes contained in the venom leading to edema; or

5520-413: The hands. People get bitten by handling snakes or in the outdoors by putting their hands on the wrong places. The next largest number of bites occur on the ankles, as snakes are often hidden or camouflaged extremely well to fend off predators. Most bite victims are bitten by surprise, and it is a comfortable fiction that rattlesnakes always forewarn their bite victims - often the bite is the first indication

5612-414: The highly efficient envenoming machines - like the rattlesnakes - with large capacity venom storage, hollow fangs that swing into position immediately before the snake bites, and spare fangs ready to replace those damaged or lost. Other research on Toxicofera , a hypothetical clade thought to be ancestral to most living reptiles, suggests an earlier time frame for the evolution of snake venom, possibly to

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5704-480: The immediate threat defeated, Rikki dedicates his life to guarding the garden, resulting in no snake daring to show its head within its walls. Director Alexandra Snezhko-Blotskaya shot an animated short film of this story titled Рикки-Тикки-Тави ( Rikki-Tikki-Tavi ) in 1965 in the Soviet Union , at the film studio Soyuzmultfilm . Ten years later, Chuck Jones adapted it for a half-hour television special in

5796-523: The intense battle and tries to retreat homeward, but is pursued by Rikki from the house to the cobra's underground nest, where the unseen final blow is delivered, although few mongooses dare to enter cobra nests, as they potentially give the cobras too much advantage. Fearing the worst, Darzee mourns what he thinks to be Rikki's death via song. Minutes later, Rikki emerges triumphant from the hole, declaring Nagaina dead and that she will never come out again, and Darzee changes his tune from anguish to elation. With

5888-528: The local tissue sometimes becoming tender and severely swollen within five minutes. This area may also bleed and blister, and may lead to tissue necrosis . Other common initial symptoms of pit viper and viper bites include lethargy, bleeding, weakness, nausea, and vomiting. Symptoms may become more life-threatening over time, developing into hypotension , tachypnea , severe tachycardia, severe internal bleeding, altered sensorium , kidney failure , and respiratory failure . Bites by some snakes, such as

5980-564: The lymphatic system may also allow the venom to be carried systemically. Snake venom may cause muscle damage or myotoxicity via the enzyme phospholipase A2 which disrupts the plasma membrane of muscle cells. This damage to muscle cells may cause rhabdomyolysis , respiratory muscle compromise, or both. Other enzymes such as bradykinin potentiating peptides, natriuretic peptides, vascular endothelial growth factors , proteases can also cause hypotension or low blood pressure. Toxins in snake venom can also cause kidney damage (nephrotoxicity) via

6072-444: The mass of the prey animal. Larger venom volumes allow snakes to effectively euthanize larger prey while remaining economical during strikes against smaller prey. This is an important skill as venom is a metabolically expensive resource. Venom metering is the ability of a snake to have neurological control over the amount of venom released into a target during a strike based on situational cues. This ability would prove useful as venom

6164-407: The metal chelator dimercaprol has recently been shown to potently antagonize the activity of Zn -dependent snake venom metalloproteinases in vitro . New monoclonal antibodies , polymer gels and a small molecule inhibitor called Varespladib are in development. A core outcome set (minimal list of consensus outcomes that should be used in future intervention research) for snakebite in South Asia

6256-402: The needle-sharp recurved teeth embedded in the person. While not as life-threatening as a bite from a venomous species, the bite can be at least temporarily debilitating and could lead to dangerous infections if improperly dealt with. While most snakes must open their mouths before biting, African and Middle Eastern snakes belonging to the family Atractaspididae are able to fold their fangs to

6348-473: The order of tens of millions of years, during the Late Cretaceous . Snake venom is produced in modified parotid glands normally responsible for secreting saliva. It is stored in structures called alveoli behind the animal's eyes, and ejected voluntarily through its hollow tubular fangs . Venom in many snakes, such as pit vipers, affects virtually every organ system in the human body and can be

6440-441: The presence of escaped or released non-native species. Snakebite first aid recommendations vary, in part because different snakes have different types of venom. Some have little local effect, but life-threatening systemic effects, in which case containing the venom in the region of the bite by pressure immobilization is desirable. Other venoms instigate localized tissue damage around the bitten area, and immobilization may increase

6532-409: The pressure throughout the venom delivery system. The pressurized venom travels through the primary venom duct to the secondary venom duct that leads down through the fang sheath and fang. The venom is then expelled through the exit orifice of the fang. The total volume and flow rate of venom administered into a target varies widely, sometimes as much as an order of magnitude. One of the largest factors

6624-526: The result of dry bites . In extreme cases, in remote areas, all of these misguided attempts at treatment have resulted in injuries far worse than an otherwise mild to moderate snakebite. In worst-case scenarios, thoroughly constricting tourniquets have been applied to bitten limbs, completely shutting off blood flow to the area. By the time the person finally reached appropriate medical facilities their limbs had to be amputated . Several new drugs and treatments are under development for snakebite. For instance,

6716-460: The result of imprecise timing on the snake's part, as venom may be prematurely released before the fangs have penetrated the person. Even without venom, some snakes, particularly large constrictors such as those belonging to the Boidae and Pythonidae families, can deliver damaging bites; large specimens often cause severe lacerations , or the snake itself pulls away, causing the flesh to be torn by

6808-421: The risk, Rikki emerges victorious and kills the snake, saving the child, before presenting the slain foe to the father as proof of the mongoose's victory. Later that night, Rikki hears Nag and Nagaina plot to kill the family to take over the house for their hatchlings and drive Rikki away. Nag enters the house's bathroom before dawn to make his ambush. Rikki, however, makes the first move and ambushes Nag from atop

6900-577: The same inflammatory cytokines. The toxins cause direct damage to the glomeruli in the kidneys as well as causing protein deposits in Bowman's capsule . Or the kidneys may be indirectly damaged by envenomation due to shock, clearance of toxic substances such as immune complexes, blood degradation products or products of muscle breakdown (rhabdomyolysis). In venom-induced consumption coagulopathy , toxins in snake venom promote hemorrhage via activation, consumption and subsequent depletion of clotting factors in

6992-530: The severity of the damage in this area, but also reduce the total area affected; whether this trade-off is desirable remains a point of controversy. Because snakes vary from one country to another, first aid methods also vary. Many organizations, including the American Medical Association and American Red Cross , recommend washing the bite with soap and water. Australian recommendations for snake bite treatment recommend against cleaning

7084-473: The side of their head without opening their mouth and jab a person. It has been suggested that snakes evolved the mechanisms necessary for venom formation and delivery sometime during the Miocene epoch. During the mid- Tertiary , most snakes were large ambush predators belonging to the superfamily Henophidia , which use constriction to kill their prey. As open grasslands replaced forested areas in parts of

7176-453: The snake's need to quickly subdue a threat. While employing similar venom expulsion mechanics, predatory strikes are quite different from defensive strikes. Snakes usually release the prey shortly after the envenomation allowing the prey to run away and die. Releasing prey prevents retaliatory damage to the snake. The venom scent allows the snake to relocate the prey once it is deceased. The amount of venom injected has been shown to increase with

7268-440: The snake's saliva. The fangs sometimes harbor pathogenic microbial organisms, including Clostridium tetani , and may require an updated tetanus immunization. Most snakebites, from either a venomous or a non-venomous snake, will have some type of local effect. Minor pain and redness occur in over 90 percent of cases, although this varies depending on the site. Bites by vipers and some cobras may be extremely painful, with

7360-567: The threat of snakes considerably. It is beneficial to know the species of snake that are common in local areas, or while travelling or hiking. Africa , Australia , the Neotropics , and South Asia in particular are populated by many dangerous species of snake. Being aware of—and ultimately avoiding—areas known to be heavily populated by dangerous snakes is strongly recommended. When in the wilderness, treading heavily creates ground vibrations and noise, which will often cause snakes to flee from

7452-466: The throat, whereas in the black phase of N. naja from Pakistan, almost the entire throat is black. The Indian cobra is native to the Indian subcontinent and can be found throughout India , Pakistan , Sri Lanka , Bangladesh , and southern Nepal . In India, it may or may not occur in the state of Assam , some parts of Kashmir , and it does not occur at high altitudes of over 2,000 metres (6,600 ft) and in extreme desert regions. In Pakistan, it

7544-500: The type of snake that caused a bite is often not possible. The World Health Organization says snakebites are a "neglected public health issue in many tropical and subtropical countries", and in 2017, the WHO categorized snakebite envenomation as a Neglected Tropical Disease (Category A). The WHO also estimates that between 4.5 and 5.4 million people are bitten each year, and of those figures 40–50% develop some kind of clinical illness as

7636-405: The type of snake, the size, physical condition, and temperature of the snake, the age and physical condition of the person, the area and tissue bitten (e.g., foot, torso, vein or muscle), the amount of venom injected, the time it takes for the person to find treatment, and finally the quality of that treatment. An overview of systematic reviews on different aspects of snakebite management found that

7728-412: The type of snake. Washing the wound with soap and water and holding the limb still is recommended. Trying to suck out the venom, cutting the wound with a knife, or using a tourniquet is not recommended. Antivenom is effective at preventing death from bites; however, antivenoms frequently have side effects . The type of antivenom needed depends on the type of snake involved. When the type of snake

7820-463: The underside, outside the throat region, is usually light. Patterns on the throat and ventral scales are also variable in this species. The majority of specimens exhibit a light throat area followed by dark banding, which can be 4–7 ventral scales wide. Adult specimens also often exhibit a significant amount of mottling on the throat and on the venter, which makes patterns on this species less clear relative to patterns seen in other species of cobra. With

7912-416: The venom injected, a bite from a dead snake can often contain large amounts of venom. It may be difficult to determine if a bite by any species of snake is life-threatening. A bite by a North American copperhead on the ankle is usually a moderate injury to a healthy adult, but a bite to a child's abdomen or face by the same snake may be fatal. The outcome of all snakebites depends on a multitude of factors:

8004-582: The venom of numerous snake species. Pharmaceutical companies which produce antivenom target their products against the species native to a particular area. The availability of antivenom is a major concern in some areas, including most of Africa, due to economic reasons (antivenom crisis). In Sub-Saharan Africa, the efficacy of antivenom is often poorly characterised and some of the few available products have even been found to lack effectiveness. Although some people may develop serious adverse reactions to antivenom, such as anaphylaxis , in emergency situations this

8096-445: The world, but is not always possible. Ideally the dead snake would be brought in with the person, but in areas where snake bite is more common, local knowledge may be sufficient to recognize the snake. However, in regions where polyvalent antivenoms are available, such as North America, identification of snake is not a high priority item. Attempting to catch or kill the offending snake also puts one at risk for re-envenomation or creating

8188-543: The world, some snake families evolved to become smaller and thus more agile. However, subduing and killing prey became more difficult for the smaller snakes, leading to the evolution of snake venom. The most likely hypothesis holds that venom glands evolved from specialized salivary glands. The venom itself evolved through the process of natural selection; it retained and emphasized the qualities that made it useful in killing or subduing prey. Today we can find various snake species in stages of this hypothesized development. There are

8280-568: The world. They occur most commonly in Africa , Asia , and Latin America , with rural areas more greatly affected. Deaths are relatively rare in Australia , Europe and North America . For example, in the United States, about seven to eight thousand people per year are bitten by venomous snakes (about one in 40 thousand people) and about five people die (about one death per 65 million people). The most common first symptom of all snakebites

8372-527: The wound. Traces of venom left on the skin/bandages from the strike can be used in combination with a snake bite identification kit to identify the species of snake. This speeds determination of which antivenom to administer in the emergency room. As of 2008, clinical evidence for pressure immobilization via the use of an elastic bandage is limited. It is recommended for snakebites that have occurred in Australia (due to elapids which are neurotoxic). It

8464-492: Was split into several subgenera based on various factors, including morphology, diet, and habitat. Naja naja is part of the subgenus Naja , along with all the other species of Asiatic cobras, including Naja kaouthia , Naja siamensis , Naja sputatrix , and the rest. Naja naja is considered to be the prototypical cobra species within the subgenus Naja , and within the entire genus Naja . All Asiatic species of Naja were considered conspecific with Naja naja until

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