Sea Snake Bites Research Articles

Survey on sea snakebite and related morbidity and mortality among Bangladeshi fishermen in the Bay of Bengal: A pilot study

Around two million people are engaged in marine fishing in the Bay of Bengal. Bites by sea snakes were common hazards feared by millions fishing at sea in earlier days. Current morbidity and mortality are also not known. This study was conducted to document and describe sea snake bites among selected communities of sea-going fishermen in Bangladesh. A questionnaire-based cross-sectional survey was conducted from May to October 2019 among three communities of sea-going fishermen living along the coast of the Bay of Bengal in Cox's Bazar district. Fishermen were first asked by trained interviewers to recall any sea snakebites to themselves and among their fellows on board within the last year, then within the last 5 years and at any time before that. For any bite, related information including outcome was noted. Overall, 25.4% of respondents (62 out of 244) had been bitten by sea-snakes. Mean age was 37.6(±14) years; all males. 51.6% received some sort of treatment locally; 71% hot compress and 48% tourniquets. In 80.6% the affected limb was not immobilized. The bitten site was incised in 29%. 22.6% received treatment from traditional healers, 48.4% from local hospitals, 29% from district hospital. Six victims (9.7%) suffered from severe life-threatening consequences of the sea snakebite but none died. 32% of the fishermen had seen the offending snake. Sea snakebites are potentially dangerous; therefore, educating fishermen to avoid contact with sea snakes would dramatically reduce the incidence of sea snakebites. Most bites are treated initially by local measures which are often not scientific. Provision of proper first aid and treatment might reduce mortality and morbidity. A larger survey on sea snake bites among the fishermen in all coastal areas of Bangladesh is needed to determine the nationwide burden of morbidity and mortality related to sea snakebite.

Preparation and Evaluation of a Horse Antiserum against the Venom of Sea Snake Hydrophis curtus from Hainan, China.

Sea snake venom is extremely toxic, and it can induce severe respiratory failure and cause high mortality. The most effective first aid treatment for sea snake bites is to inject antivenom as soon as possible. However, in China, there are only four types of terrestrial snake antivenoms, none of which are effective in the treatment of sea snake bites. In order to develop an antivenom for the dominant species of sea snakes in Chinese seas, Hydrophis curtus venom (HcuV) was chosen as the antigen to immunize horses. From immune plasma, a high-titer Hydrophis curtus antivenom (HcuAV) was prepared. In vitro assessment showed that HcuAV had a cross-neutralizing capacity against HcuV and Hydrophis cyanocinctus venom (HcyV). In vivo assessment indicated that HcuAV injection could significantly improve the survival rates of the HcuV and HcyV envenomated mice (0% to 100% and 87.5%, respectively) when it was injected at a sufficient amount within the shortest possible time. In addition, HcuAV could also effectively alleviate multiple organ injuries caused by HcuV. These results provide experimental support for the future clinical application of HcuAV.

Australian Sea Snake Envenoming Causes Myotoxicity and Non-Specific Systemic Symptoms - Australian Snakebite Project (ASP-24).

Background: Sea snakes are venomous snakes found in the warm parts of the Indo-Pacific, including around Australia. Most sea snake envenoming causes myotoxicity, but previous Australian case reports describe neurotoxicity. We aimed to describe the epidemiology and clinical presentation of Australian sea snake envenoming and the effectiveness of antivenom. Methods: Patients were recruited to the Australian Snakebite Project (ASP), an Australia-wide prospective observational study recruiting all patients with suspected or confirmed snakebite >2 years. Information about demographics, bite circumstances, species involved, clinical and laboratory features of envenoming, and treatment is collected and entered into a purpose-built database. Results: Between January 2002 and August 2020, 13 patients with suspected sea snake bite were recruited to ASP, 11 were male; median age was 30 years. Bites occurred in Queensland and Western Australia. All patients were in or around, coastal waters at the time of bite. The species involved was identified in two cases (both Hydrophis zweifeli). Local effects occurred in 9 patients: pain (5), swelling (5), bleeding (2), bruising (1). Envenoming occurred in eight patients and was characterised by non-specific systemic features (6) and myotoxicity (2). Myotoxicity was severe (peak CK 28200 and 48100 U/L) and rapid in onset (time to peak CK 13.5 and 15.1 h) in these two patients. Non-specific systemic features included nausea (6), headache (6), abdominal pain (3), and diaphoresis (2). Leukocytosis, neutrophilia, and lymphopenia occurred in both patients with myotoxicity and was evident on the first blood test. No patients developed neurotoxicity or coagulopathy. Early Seqirus antivenom therapy was associated with a lower peak creatine kinase. Conclusion: While relatively rare, sea snake envenoming is associated with significant morbidity and risk of mortality. Early antivenom appears to have a role in preventing severe myotoxicity and should be a goal of therapy.

De Novo Venom-Gland Transcriptomics of Spine-Bellied Sea Snake (Hydrophis curtus) from Penang, Malaysia-Next-Generation Sequencing, Functional Annotation and Toxinological Correlation.

Envenomation resulted from sea snake bite is a highly lethal health hazard in Southeast Asia. Although commonly caused by sea snakes of Hydrophiinae, each species is evolutionarily distinct and thus, unveiling the toxin gene diversity within individual species is important. Applying next-generation sequencing, this study investigated the venom-gland transcriptome of Hydrophis curtus (spine-bellied sea snake) from Penang, West Malaysia. The transcriptome was de novo assembled, followed by gene annotation and sequence analyses. Transcripts with toxin annotation were only 96 in number but highly expressed, constituting 48.18% of total FPKM in the overall transcriptome. Of the 21 toxin families, three-finger toxins (3FTX) were the most abundantly expressed and functionally diverse, followed by phospholipases A2. Lh_FTX001 (short neurotoxin) and Lh_FTX013 (long neurotoxin) were the most dominant 3FTXs expressed, consistent with the pathophysiology of envenomation. Lh_FTX001 and Lh_FTX013 were variable in amino acid compositions and predicted epitopes, while Lh_FTX001 showed high sequence similarity with the short neurotoxin from Hydrophis schistosus, supporting cross-neutralization effect of Sea Snake Antivenom. Other toxins of low gene expression, for example, snake venom metalloproteinases and L-amino acid oxidases not commonly studied in sea snake venom were also identified, enriching the knowledgebase of sea snake toxins for future study.

Secondary Hyperkalemic Paralysis and Acute Kidney Injury Due to Rhabdomyolysis Caused by Sea-Snake Envenomation

Sea-snakes are a common occupational hazard to fishermen in Asian coastal waters.Sea snake venom contains both myotoxins and neurotoxins. Hyperkalemia is a rare cause of acute flaccid paralysis. Myotoxicity result in rhabdomyolysis due to muscle necrosis, acute kidney injury(AKI) and hyperkalemia sometimes resulting in flaccid paralysis. We report here a 50 year old fisherman who presented with muscle pain, AKI,hyperkalemia and quadriparesis with respiratory paralysis. History revealed sea snake bite on his right hand. His serum creatine kinase and lactate dehydrogenase enzymes were elevated several fold.Urine myoglobin was positive. He was treated with hemodialysis and other supportive measures. He required total of 7 hemodialysis sessions and was discharged with serum creatinine of 2mg/dl on day 25.His muscle paralysis was attributed to hyperkalemia as he recovered dramatically with hemodialysis support.

Sea Snake Bites Resulted in a Mimic of Brain Death

A 69 year old man with deep coma presented after an alleged history of sea snake bite. Patient presented with irresponsiveness to painful stimuli, complete ptosis, internal and external ophthalmoplegia. He was given continuous ventilator support despite signs of brain stem dysfunction. On admission day 20, the patient was weaned off ventilator and discharged from the hospital. Whenever treating patients who were suspected with a history of snake bite, an emergency physician should always consider severe envenomation in the differential diagnosis of acute neuroparalytic syndrome, which may avert the unfortunate misdiagnoses of brain death.

Sea snake harvest in the gulf of Thailand.

Conservation of sea snakes is virtually nonexistent in Asia, and its role in human-snake interactions in terms of catch, trade, and snakebites as an occupational hazard is mostly unexplored. We collected data on sea snake landings from the Gulf of Thailand, a hotspot for sea snake harvest by squid fishers operating out of the ports of Song Doc and Khanh Hoi, Ca Mau Province, Vietnam. The data were collected during documentation of the steps of the trading process and through interviewers with participants in the trade. Squid vessels return to ports once per lunar synodic cycle and fishers sell snakes to merchants who sort, package, and ship the snakes to various destinations in Vietnam and China for human consumption and as a source of traditional remedies. Annually, 82 t, roughly equal to 225,500 individuals, of live sea snakes are brought to ports. To our knowledge, this rate of harvest constitutes one of the largest venomous snake and marine reptile harvest activities in the world today. Lapemis curtus and Hydrophis cyanocinctus constituted about 85% of the snake biomass, and Acalyptophis peronii, Aipysurus eydouxii, Hydrophis atriceps, H. belcheri, H. lamberti, and H. ornatus made up the remainder. Our results establish a quantitative baseline for characteristics of catch, trade, and uses of sea snakes. Other key observations include the timing of the trade to the lunar cycle, a decline of sea snakes harvested over the study period (approximately 30% decline in mass over 4 years), and the treatment of sea snake bites with rhinoceros horn. Emerging markets in Southeast Asia drive the harvest of venomous sea snakes in the Gulf of Thailand and sea snake bites present a potentially lethal occupational hazard. We call for implementation of monitoring programs to further address the conservation implications of this large-scale marine reptile exploitation.

Enhydrina schistosa (Elapidae: Hydrophiinae) the most dangerous sea snake in Sri Lanka: Three case studies of severe envenoming

Sea snakes are highly venomous and inhabit tropical waters of the Indian and Pacific Oceans. Enhydrina schistosa is a common species of sea snake that lives in the coastal waters, lagoons, river mouths and estuaries from the Persian Gulf through Sri Lanka and to Southeast Asia. It is considered one of the most aggressive sea snakes in Sri Lanka where fishermen and people wading are at high risk. However, sea snake bites are rarely reported. In this report, we describe three cases where E. schistosa was the offending species. These three patients presented to two hospitals on the west coast of Sri Lanka within the course of 14 months from November 2011 with different degrees of severity of envenoming. The first patient was a 26-year-old fisherman who developed severe myalgia with very high creatine kinase (CK) levels lasting longer than 7 days. The second patient was a 32-year-old fisherman who developed gross myoglobinuria, high CK levels and hyperkalaemia. Both patients recovered and their electromyographic recordings showed myopathic features. The nerve conduction and neuromuscular transmission studies were normal in both patients suggesting primary myotoxic envenoming. The third patient was a 41-year-old man who trod on a sea snake in a river mouth and developed severe myalgia seven hours later. He had severe rhabdomyolysis and died three days later due to cardiovascular collapse. In conclusion, we confirm that E. schistosa is a deadly sea snake and its bite causes severe rhabdomyolysis.

A case of a sea snake bite resulting in fatal envenoming

Sea snakes of Sri Lanka are among the most venomous snakes in the island although they have not received much attention in the last few decades. According to data from other countries, they may be more toxic than highly venomous land snakes in the island. Most sea snake species found around Sri Lanka are gentle and inoffensive and will only bite when provoked, but certain species like Astrotia stokesii and Enhydrina schistosa are known to be much more aggressive. We report a case of fatal sea snake envenoming in Sri Lanka. DOI: http://dx.doi.org/10.4038/cmj.v57i4.5089 Ceylon Medical Journal 2012; 57 : 174-175

Molecular evidence that the deadliest sea snake Enhydrina schistosa (Elapidae: Hydrophiinae) consists of two convergent species

We present a striking case of phenotypic convergence within the speciose and taxonomically unstable Hydrophis group of viviparous sea snakes. Enhydrina schistosa, the ‘beaked sea snake’, is abundant in coastal and inshore habitats throughout the Asian and Australian regions, where it is responsible for the large majority of recorded deaths and injuries from sea snake bites. Analyses of five independent mitochondrial and nuclear loci for populations spanning Australia, Indonesia and Sri Lanka indicate that this ‘species’ actually consists of two distinct lineages in Asia and Australia that are not closest relatives. As a result, Australian “E. schistosa” are elevated to species status and provisionally referred to Enhydrinazweifeli. Convergence in the characteristic ‘beaked’ morphology of these species is probably associated with the wide gape required to accommodate their spiny prey. Our findings have important implications for snake bite management in light of the medical importance of beaked sea snakes and the fact that the only sea snake anti-venom available is raised against Malaysian E. schistosa.

Emerging extra-intestinal infections with Aeromonas hydrophila in coastal region of southern Karnataka

Aeromonas species are gram-negative rods usually isolated from the gastrointestinal tract. They have been occasionally reported as a cause of extra-intestinal infections such as cellulitis, cholangitis, necrotizing fascitis, meningitis, bacteremia, or peritonitis in both immunocompetent and immunocompromised patients. To determine the role and possible pathogenesis of Aeromonas in extra-intestinal infections. Retrospective analysis carried out at Kasturba Hospital Manipal, Karnataka in the months of January and February 2007. Clinical manifestations and management of eight cases of extra-intestinal infections caused by A. hydrophila , from the south Karnataka coastal region were reviewed. The isolates were identified with the help of biochemical tests using standard guidelines. All patients acquired Aeromonas infections in the community. Five (62.5%) had underlying illnesses, such as liver disease, diabetes mellitus or malignancy. Five (62.5%) had polymicrobial infections, and three (37.5%) were complicated with bacteremia. These included three patients with ulcers or abscess over the lower leg, two with cellulitis due to snake bite and one each with pelvic inflammatory disease, spontaneous bacterial peritonitis and pneumonia. A. hydrophila was found to be a causative agent of pelvic inflammatory disease or cellulitis following sea snake bite, and such a clinical scenario has not been previously described. Seven patients survived the illness. Isolation of A. hydrophila from extra-intestinal specimens demands utmost clinical and microbiological vigilance in diagnosis, since the organism can cause serious infections among immunocompromised as well as immunocompetent individuals.

Two Sri Lankan cases of identified sea snake bites, without envenoming

Sea snakes are among the most venomous creatures encountered around coasts and reefs, in estuaries, rivers and at sea. Their venoms are more toxic than those of land snakes. However, they are rarely aggressive or menacing. Bites have become unusual with the advent of modern fishing methods but the two encounters we report, in the Indian Ocean off the shores of Sri Lanka, emphasise that sea snake bites may not result in envenoming.

Sea snake envenomation

Sea snakes are common venomous reptiles found in the warmer waters of the Pacific and Indian Oceans. The most common circumstance for sea snake bite is an accidental encounter by a fisherman while emptying a fishing net. The venom is extremely toxic and most significant on the nervous and musculoskeletal systems. Significant envenomation occurs in about 20% of bites, with death occurring in about 3% of bites. Death most often occurs from respiratory arrest secondary to neurotoxicity. Myotoxins may cause muscle pain and stiffness and lead to clinically significant rhabdomyolysis and possible acute renal failure. Sea snake bites should all be considered a medical emergency. Immobilization of the victim with compression of the envenomed area is important first aid, followed by transporting the victim to an emergency medical facility. Artificial ventilation and hydration with crystalloid may be important lifesaving maneuvers. Sea snake antivenom may be critical for survival in a significant envenomation.

Snake Bite, Rhabdomyolysis, and Renal Failure

APPROXIMATELY 5 million snake bites, scorpion stings, and anaphylactic reactions to insect stings occur worldwide annually, causing over 100,000 human deaths each year.1 Snake bites are estimated to cause 30,000 deaths annually in Asia and 1,000 deaths each in Africa and South America. By contrast, in Australia and the United States, the number of deaths is minimal. The animal toxin can cause a spectrum of effects, from local reaction with pain and swelling to severe systemic response and vital organ involvement. Intravascular hemolysis, disseminated intravascular coagulation, rhabdomyolysis, and muscular paralysis are common and can lead to or contribute to devastating hemodynamic effects. Myoglobinuria and hemoglobinuria are often observed. In the tropics, animal toxins are an important cause of rhabdomyolysis. Insect stings (wasps, hornets, and bees) and snake bites are the most common cause of myoglobinuric acute renal failure (ARF). Examination of renal biopsy specimens using immunoperoxidase staining techniques has revealed myoglobin in the renal tubules of 60% of patients with various tropical diseases, yet clinical myoglobinuria is observed in only 9%. Snakes known to have toxins with myotoxicity include Notechis scutatus (Australian tiger snake), Oxyuranus scutellatus (Australian Taipan snake), Bungarus multicinctus (Taiwanese krait), Bungarus caeruleus (Indian krait), Crotalus durissus terrificus (South American rattlesnake), Micropechis ikeheka (small-eyed snake of New Guinea), Pseudechis australis (Mulga snake), Pseudechis colletti (Collett’s snake), Pseudechis affinis (Dugite snake), Pseudechis porphyriacus (red-bellied black snake), Pseudonaja textitis (common brown snake), Tropidechis carinatus (rough-scaled snake), Austrelaps superbus (copperhead), Cryptophis nigrescens (smalleyed snake), Vipera russelli pulchella (Sri Lankan Russell’s viper), and sea snakes. All myotoxic snake venoms contain phospholipase A2, which is responsible for the rhabdomyolysis. The venoms also have neurotoxin components. Some have presynaptic effects, while a few have predilection for postsynaptic action. Postsynaptic neurotoxins account for approximately 60% of the toxic protein of sea snakes (Enhydrina schistosa). Nevertheless, the clinical picture of poisoning is predominantly myotoxic rather than neurotoxic.2 Muscular pains and myoglobinuria are the most characteristic symptoms in human snake bite victims. Myalgia starts after the bite, reaches a peak a few days later, and usually lasts for 1 week. Muscular pains are associated with myoglobinuria, muscular paresis, and areflexia. Myoglobinuria lasts for approximately 1 week, while muscular paresis and areflexia can last as long as 3 weeks. ARF occurs in the majority of patients. Hyperkalemia, hyperuricemia, hypocalcemia, hyperphosphatemia, and a low ratio of serum urea nitrogen to serum creatinine concentrations are common laboratory findings. Serum creatine phosphokinase and lactate dehydrogenase levels are variable. Of clinical interest is the observation that hemodialysis in sea snake (Enhydrina schistosa) bite victims improves the muscular symptoms, including paresis. Although the clinical aspects of the Australian elapid and sea snake bites are well described, little is known about the sequential pathologic changes of the effects of myoglobinuria in the kidney. A recent renal pathologic study in mice at

Snake bite in Kelantanese children: A five year experience

The records associated with 83 children from 16 months to 12 years of age who were admitted with snake bite to Kota Bharu General Hospital and University Hospital, Universiti Sains Malaysia over a 5 year period were reviewed. Elapid bites were more common than viper bites while sea-snake bites were not recorded. Symptoms were relatively mild, the common clinical features being pain and local swelling. Antivenom therapy was required in 11 children. Only three of the 11 children developed minor adverse reactions to antivenom. Four of the 83 required ventilatory support for respiratory failure and two children died.

Poisonous fish and seasnakes in the Arabian Gulf

SummaryA case history is given, followed by a discussion of the management of seasnake bites and poisonous fish stings with guidance on differentiating between the two types of injury.

Seasnake bites in a freshwater lake.

One species of venomous seasnake, Hydrophis semperi, is found in Lake Taal, a large freshwater lake in the Philippines. The first series of seasnake bites occurring in freshwater is described. In one small fishing village, there were eight definite bites and one probably attributable death. In three of the eight patients, specific antibodies to Hydrophis venom were demonstrated. In contrast to previous seasnake studies, there was an absence of asymptomatic cases. The possible public health importance of freshwater seasnake bites in the Philippines needs further investigation.

ENVENOMATION BY SEA SNAKE IN QUEENSLAND

A case of a near-fatal sea snake bite, believed to the the first such case in Australia, is presented. The two-year-old girl victim became unconscious and apnoeic soon after envenomation by an Astrotia stokesii, and required artificial ventilation for 22 hours. She regained consciousness 4 1/2 hours after the administration of antivenom. The recovery phase was marked by hallucinations and tonic spasms. The patient made a full recovery before discharge from hospital.

Haemodialysis in Poisoning by Sea-snake Venom

Myoglobinuria, renal failure, and muscular weakness or paralysis were noted in two patients following sea-snake bite. A pathological study by biopsy showed renal tubular necrosis and myonecrosis. Both patients were treated by haemodialysis, and there was a remarkable improvement in the muscular symptoms. Recovery was complete in both cases. It is believed that muscular paralysis was the effect of hyperkalaemia and uraemia on the muscles sensitized by the toxic effect of the sea-snake venom. Removal of potassium and uraemic factors by dialysis thus led to the rapid improvement of the muscular activity. Haemodialysis seems to be a useful alternative method to sea-snake antivenom in the treatment of sea-snake bite poisoning.

A study on sea-snake venom phospholipase A

A study has been made of the action of phospholipase A in heated sea-snake venom on purified phospholipids, and the phospholipids of plasma and intact muscle cell. The enzyme required activation by deoxycholate in order to achieve maximal hydrolysis of purified lecithin, phosphatidylserine and the phospholipids of human plasma. The hydrolysis of purified phosphatidylethanolamine is inhibited by deoxycholate. The choline, serine and ethanolamine phosphatides of the intact muscle cell were also hydrolyzed. The results are discussed in relation to the myolytic action of sea-snake bite.