Clinical and epidemiologic profile and predictors of outcome of poisonous snake bites - an analysis of 1,500 cases from a tertiary care center in Malabar, North Kerala, India

Strikes and stripes of the Saw-scaled Viper in the Western Ghats-A case series

We describe 5 cases of envenomation and complications related to saw scaled viper (Echis carinatus) bites from the Western Ghats region of Karnataka over a period of 5 years (December 2019-May 2023). Although the smallest member of the Big Four, Saw Scaled viper envenomation is associated with significant morbidity. In our region, envenomation appears to be rare. The careful review of all these cases has suggested VICC with one patient having persistent coagulopathy despite adequate ASV administration, and three patients developing anaphylaxis. It needs to be brought to notice that the complications due to envenoming run high, despite timely administration of ASV. Through these cases, we want to contribute evidence suggesting variable efficacy of Indian polyvalent ASV for Echis carinatus bites and the need for updating protocols for the same.

Comparative functional characterization and in vitro immunological cross-reactivity studies on Daboia russelii and Craspedocephalus malabaricus venom

BACKGROUND

Snake venom is a complex mixture of organic and inorganic constituents, including proteins and peptides. Several studies showed that antivenom efficacy differs due to intra- and inter-species venom variation.

METHODS

In the current study, comparative functional characterization of major enzymatic proteins present in Craspedocephalus malabaricus and Daboia russelii venom was investigated through various in vitro and immunological cross-reactivity assays.

RESULTS

The enzymatic assays revealed that hyaluronidase and phospholipase A2 activities were markedly higher in D. russelii. By contrast, fibrinogenolytic, fibrin clotting and L-amino acid oxidase activities were higher in C. malabaricus venom. ELISA results suggested that all the antivenoms had lower binding potential towards C. malabaricus venom. For D. russelii venom, the endpoint titration value was observed at 1:72 900 for all the antivenoms. In the case of C. malabaricus venom, the endpoint titration value was 1:2700, except for Biological E (1:8100). All these results, along with the avidity assays, indicate the strength of venom-antivenom interactions. Similarly, the western blot results suggest that all the antivenoms showed varied efficacies in binding and detecting the venom antigenic epitopes in both species.

CONCLUSIONS

The results highlight the need for species-specific antivenom to better manage snakebite victims.

Clinico-Epidemiological Profile, Trends, and Health-Related Outcomes of Snakebite Victims: A One-Year Prospective Study from Eastern India

INTRODUCTION

Snakebite envenomation is a significant life-threatening public health problem in Southeast Asia (SEA). In this region, India reported the largest number of snakebite deaths from 2000 to 2019 (1.2 million), with an average of 58,000 deaths yearly.

METHODS

This prospective observational study was carried out among snakebite victims at the emergency department (ED) of a tertiary care public sector hospital in eastern India.

RESULTS

A total of 145 cases of venomous snakebite were investigated. More than half (n = 81, 56%) of the snakebite victims were between 17 to 45 years. Most of the snakebite victims were male (68%) and were farmers (53%) by occupation. The majority of snakebites occurred during the daytime (76%) and while outdoors (67%). Most victims sustained a bite on the lower extremity (71%). The peak incidence of snakebites occurred from June to September (69%). Three-quarters of all patients were unaware of the required first aid measures following a snakebite. Among the 145 venomous snakebites, 48 were presumptively identified as the Indian cobra, 32 by the Indian krait, 56 by the Russel's viper, and 9 by saw-scaled viper. The mean duration from the snakebite to the onset of systemic effects in the Indian cobra was 52 ± 14.28 min, 66 ± 18.35 min in the Indian krait, 42 ± 13.47 min in Russel's viper, and 48 ± 16.38 min in saw-scaled viper. Respiratory failure was the commonly observed complication following an elapid envenomation. The mortality rate was 2.1% among the patients treated with antivenom.

CONCLUSIONS

Snakebite is considered an occupational hazard in India, commonly affecting the young population in their productive period. The peak incidence was during monsoon season, and the majority had neurotoxic envenomation following an elapid bite (55%) that contributed to the increased mortality and morbidity among young adults. Of the 145 patients, the majority (84%) recovered fully with treatment; 16% of the victims developed morbidity viz cellulitis, respiratory failure, acute renal failure, compartment syndrome, local tissue necrosis, intracerebral hemorrhage, and disseminated intravascular coagulation. Appropriate first aid measures and timely medical intervention can significantly improve the treatment outcome following snakebites.

Clinical characteristics of snakebite patients attending a tertiary hospital in Hangzhou, southeast China

BACKGROUND

Venomous snakebite is a neglected yet an important public health problem in China, and few studies have focused on them so far. The aim of this study is to investigate clinical characteristics of snakebites patients in a tertiary hospital in Hangzhou, southeast China.

METHODS

A total of 416 snakebite cases were included in this retrospective study. The data were collected from the medical records including demographics, clinical manifestations, management and outcomes.

RESULTS

Of the 416 patients with venomous snakebites, 248 were male, and the average age was 54.6 years. The majority of cases occurred in rural in May to September. Out of all the venomous bites, Gloydius brevicaudus accounted for the highest percentage (55.3%). Hands were the most vulnerable site to snakebites (47.4%). Patients had clinical manifestations of pain (100%), swelling (100%), wound necrosis (25.7%), hemorrhagic blister (18.3%), and blister (8.7%). Three hundred and ninety-two patients received antivenom administration, and most were treated within six hours after bites. Twenty-six patients received surgical treatments, and 90 patients developed venom-induced consumption coagulopathy. No deaths have occurred in this study.

CONCLUSION

Hangzhou is one of the regions with high affecting of snakebites in China. The results of this study will increase the understanding of the clinical characteristics of venomous snakebites in Hangzhou area.

Knowledge and practices related to snakebite prevention, China: a cross-sectional study

Objective

To assess knowledge and practices related to snakebite prevention among Chinese residents.

Methods

By using a multistage random sampling approach augmented by snowball sampling, we surveyed residents from 10 provinces, one municipality and one autonomous region south of the Yangtze River Basin between May 2022 and February 2023. We supplemented the data with a national online survey. We used a χ2-test to identify differences in knowledge and behaviour across various demographic characteristics. We conducted multifactor logistic regression analyses to evaluate factors potentially influencing snakebite knowledge and practices.

Findings

We obtained 55 775 valid survey responses, 16 200 respondents from the face-to-face survey and 39 575 respondents from the online survey. Only 25.7% (14 325) respondents demonstrated adequate knowledge about snakebites whereas 25.6% (14 295) respondents knew basic first-aid practices or preventive behaviours. Age, marital status, educational attainment, occupation, type of residence and frequency of exposure to nature are significant independent variables affecting snakebite knowledge (P-values: < 0.05). On the other hand, gender, age, marital status, educational attainment, occupation and type of residence were significant independent variables affecting the behaviour of snakebite prevention and first aid (P-values: < 0.05).

Conclusion

There is a notable shortfall in knowledge, first aid and preventive behaviours among Chinese residents regarding snakebites. Misguided first aid practices can severely compromise the effectiveness of evidence-based therapeutic interventions. Consequently, improving health education concerning snakes and snakebites in this population is needed.

Venomous snakebites in children: a 10 year experience in South China

INTRODUCTION

Many studies have focused on snakebites in adults, but very few have described snakebites in children.

METHODS

We reviewed the clinical characteristics and outcomes of children with venomous snakebites aged less than 15 years who presented to a regional medical centre in South China from January 2013 to December 2022.

RESULTS

A total of 69 envenomed patients were analyzed in our study; 42 (60.9 per cent) patients were male, and 59 (85.5 per cent) reported lower limb bites. Most bites (89.8 per cent) occurred between April and October. Twenty-seven patients received first aid management, and 47 required admission to the general ward. Antivenom was administered to 58 patients, glucocorticoids to 43 patients, antibiotics to 48 patients, and tetanus antitoxin to 40 patients. No fatalities were reported. The most common snake identified was Trimeresurus albolabris. Four were classified as dry bites, 15 as mild, 43 as moderate, and seven as severe. The most common local signs were pain and swelling, while the most common systemic effects were haematological complications. Patients with high severity scores had significantly higher lactate dehydrogenase activities, creatine kinase isoenzyme activities, aspartate aminotransferase activities, D-dimer concentrations, prothrombin times and lower fibrinogen concentrations. In a receiver operating characteristic curve analysis of the values with the highest Youden index, the following cut-offs proved significant: lactate dehydrogenase activity > 248.1 U/L, creatine kinase isoenzyme activities > 17.5 U/L, fibrinogen concentration < 1,455 mg/L, D-dimer concentration > 437.0 µg/L, aspartate aminotransferase activity > 26.1 U/L, and prothrombin time > 15.2 seconds.

DISCUSSION

This study provides insight into the epidemiology, clinical profile, and management of snakebites in children. Data from the present study were compared with those from our previous adult study. Limitations include that 50.7 per cent of our snakebites were attributed to Trimeresurus albolabris. Therefore, the results of our study may not be generalizable to all snakebites.

CONCLUSION

The clinical symptoms were more severe in children than in adults in our previous study. Even though there were no fatalities, close monitoring should be performed to detect haematological and other potentially fatal complications promptly.

Presentation, treatment profiles, and outcome of snake bite patients presented in emergency department at a tertiary hospital in Eastern Nepal

Background

Snake bite is one of the most common animal bites in Nepal. Different species of snake cause different clinical presentations. The incidence of snakebite is very high in rural Nepal. The objectives were to assess the presenting pattern, demographic profile, outcome, and treatment profiles of snakebite victims admitted to the emergency ward.

Materials and Methods

A retrospective cross-sectional study was conducted among the patients who presented in emergency department with alleged history of snake bites from 2015 to 2016. The patient's record files were reviewed and the relevant data were recorded on a self-designed proforma. Descriptive statistics were calculated using SPSS version 11.5.

Results

Out of 137 snakebite victims, 73 (53.3%) were female. The mean age was 35.17 ± 18.27 years. The upper limb (59%) was the most common site for snake bites followed by the lower limb (35.1%). Fifty patients (36.2%) were bitten by snakes during night (20.00-2.59 AM). Twenty-eight (20.4%) patients presented with ptosis as the most common sign and symptom followed by diplopia (15.3%). Out of 137 patients, 39 (28.5%) were admitted, 65 (47.4%) discharged, and 12 (8.8%) patients expired. Antisnake venom was given to 30 patients among which 23 patients (76.7%) were improved.

Conclusions

Snake bite is one of the major problems in rural Nepal. It can be easily managed if treatment is given properly and in a timely manner. The importance of effective first aid management and effective treatment have to be disseminated among the peoples in rural areas via social media and radio.

Evaluation of the role of neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and mean platelet volume (MPV) time series as predictors of diagnosis and prognosis of hemotoxic snakebite

BACKGROUND

This study aimed to assess the predictive value of NLR, PLR, and MPV time series for diagnosis and prognosis of hemotoxic snakebite envenomation.

METHODS

This is a prospective study among snakebite patients admitted to the Poison Control Center of Ain Shams University Hospitals and Assiut University Hospitals from the beginning of July 2019 to the end of October 2021. Patients were classified according to their clinical severity into three groups: mild, moderate, and severe.

RESULTS

The maximum incidence of snakebite was found in males (95%) from rural areas (80%); at lower limbs (70%); at night (51%); and during the autumn season (43.3%). The admission NLR and PLR can predict hemotoxic snakebite envenomation with an AUC of 0.940 and 0.569. The combination of NLR with PLR can develop a more predominant prediction of snakebite envenomation with an area under the curve (AUC) of 0.979. Furthermore, higher admission NLR and PLR levels are associated with prolonged hospital stays.

CONCLUSION

While NLR and PLR levels may be helpful in the diagnosis of snakebite, MPV plays no part in the prognosis of snakebite patients. Serial NLR, PLR initially, at 24 hours, and predischarge can be used to evaluate the early treatment response.

Clinical Risk Factors Associated with Poor Outcomes in Snake Envenoming: A Narrative Review

Snakebite-related fatalities disproportionately affect populations in impoverished socio-economic regions, marked by limited access to adequate healthcare and constrained antivenom availability. Early medical intervention is pivotal in mitigating mortality and morbidity associated with snakebite envenoming (SBE). While clinical assessment remains fundamental in treating SBE, this review aims to spotlight objective parameters that could also affect outcomes. Selected studies that identify factors associated with poor outcomes are predominantly region-specific, single-site, and observational, yet collectively reveal similar findings. They consistently report factors such as treatment delays, susceptibility in vulnerable groups such as children and pregnant women, as well as various biochemical and haematological abnormalities. Acute kidney injury (AKI), low platelets, leucocytosis, abnormal coagulation, and elevated creatine kinase (CK) all show an association with poor outcomes. Furthermore, recognising rare and unusual SBE presentations such as adrenal insufficiency, severe hypertension, intracranial haemorrhage, acute angle closure glaucoma, and bowel ischaemia also has a bearing on outcomes. Despite the integration of these parameters into clinical decision tools and guidelines, the validation of this evidence is limited. This review underscores the imperative for high-quality, multi-centre studies aligned with consensus-driven Core Outcome Sets (COS) and Patient-Reported Outcome Measures (PROMS) to validate and strengthen the current evidence.

Proteomic characteristics of six snake venoms from the Viperidae and Elapidae families in China and their relation to local tissue necrosis

Patients envenomed by snakes from the Viperidae and Elapidae families in China often have varying degrees of local tissue necrosis. Due to the relative clinical characteristics of local tissue necrosis and ulceration following envenoming, this study has analyzed the proteome of six snake venoms from the Viperidae and Elapidae family, and the toxin profiles of each snake were compared and correlated with the clinical manifestations that follow cytotoxic envenoming. Deinagkistrodon acutus and Naja atra envenomation induce severe ulceration, which is absent in Bungarus multicinctus envenomation and mild in the other three vipers. It is interesting to note that the proportion of c-type lectins (CTL) (20.63%) in Deinagkistrodon acutus venom was relatively high, which differs from the venom of other vipers. In addition, three-fingered toxin (3FTx) (2.15%) is present in the venom of Deinagkistrodon acutus, but has not been detected in the remaining three vipers. Snake venom metalloprotease (SVMP) (34.4%-44.7%), phospholipase A2 (PLA2) (9.81%-40.83%), and snake venom serine protease (SVSP) (9.44%-16.2%) represent the most abundant families of toxin in Viperidae venom. The Elapidae venom proteome was mainly composed of neurotoxins and cytotoxins, including 3FTx (39.28%-60.08%) and PLA2 (8.24%-58.95%) toxins, however, the proportion of CRISPS (26.36%) in Naja atra venom was relatively higher compared to Bungarus multicinctus venom. Significant differences in SVMP, SVSP, and 3FTx expression levels exist between the Viperidae and the Elapidae family. The main toxins responsible for the development of tissue necrosis and ulcerations following Viperidae envenoming are hematotoxins (SVSMP, SVSP) and myotoxins (PLA2). Deinagkistrodon acutus venom contains high levels of CTL and traces of 3FTx, leading to more severe local necrosis. However, Naja atra venom can also cause severe local necrosis through the effects of myotoxin (3FTx, CRISP, PLA2). Bungarus multicinctus venom does not contain myotoxins, resulting in pure systemic neurological manifestations no obvious necrosis of local tissue in patients.

The Need for Next-Generation Antivenom for Snakebite Envenomation in India

The limitations posed by currently available antivenoms have emphasized the need for alternative treatments to counteract snakebite envenomation. Even though exact epidemiological data are lacking, reports have indicated that most global snakebite deaths are reported in India. Among the many problems associated with snakebite envenomation, issues related to the availability of safer and more efficient antivenoms are of primary concern. Since India has the highest number of global snakebite deaths, efforts should be made to reduce the burden associated with snakebite envenoming. Alternative methods, including aptamers, camel antivenoms, phage display techniques for generating high-affinity antibodies and antibody fragments, small-molecule inhibitors, and natural products, are currently being investigated for their effectiveness. These alternative methods have shown promise in vitro, but their in vivo effectiveness should also be evaluated. In this review, the issues associated with Indian polyvalent antivenoms in neutralizing venom components from geographically distant species are discussed in detail. In a nutshell, this review gives an overview of the current drawbacks of using animal-derived antivenoms and several alternative strategies that are currently being widely explored.

Fangs in the Ghats: Preclinical Insights into the Medical Importance of Pit Vipers from the Western Ghats

The socioeconomic impact of snakebites in India is largely attributed to a subset of snake species commonly known as the 'big four'. However, envenoming by a range of other clinically important yet neglected snakes, a.k.a. the 'neglected many', also adds to this burden. The current approach of treating bites from these snakes with the 'big four' polyvalent antivenom is ineffective. While the medical significance of various species of cobras, saw-scaled vipers, and kraits is well-established, the clinical impact of pit vipers from regions such as the Western Ghats, northeastern India, and the Andaman and Nicobar Islands remains poorly understood. Amongst the many species of snakes found in the Western Ghats, the hump-nosed (Hypnale hypnale), Malabar (Craspedocephalus malabaricus), and bamboo (Craspedocephalus gramineus) pit vipers can potentially inflict severe envenoming. To evaluate the severity of toxicity inflicted by these snakes, we characterised their venom composition, biochemical and pharmacological activities, and toxicity- and morbidity-inducing potentials, including their ability to damage kidneys. Our findings highlight the therapeutic inadequacies of the Indian and Sri Lankan polyvalent antivenoms in neutralising the local and systemic toxicity resulting from pit viper envenomings.

Clinical aspects of snakebite envenoming and its treatment in low-resource settings

There is increasing recognition of the public health importance of snakebite envenoming. Worldwide annual incidence is likely to be 5 million bites, with mortality exceeding 150 000 deaths, and the resulting physical and psychological morbidity leads to substantial social and economic repercussions. Prevention through community education by trained health workers is the most effective and economically viable strategy for reducing risk of bites and envenoming. Clinical challenges to effective treatment are most substantial in rural areas of low-resource settings, where snakebites are most common. Classic skills of history taking, physical examination, and use of affordable point-of-care tests should be followed by monitoring of evolving local and systemic envenoming. Despite the profusion of new ideas for interventions, hyperimmune equine or ovine plasma-derived antivenoms remain the only specific treatment for snakebite envenoming. The enormous interspecies and intraspecies complexity and diversity of snake venoms, revealed by modern venomics, demands a radical redesign of many current antivenoms.

Russell's viper envenomation induces rectus sheath haematoma

Snakebite envenomation causes systemic and local manifestations, which result from the individual or synergistic actions of multiple venom components. The pathological hallmarks of medically important venomous snakes such as the Indian Russell's viper (Daboia russelii) are well known. Envenomation by Russell's viper is typically characterised by coagulopathies, muscular damage, nephrotoxicity, and neurotoxicity. However, recent reports have revealed several unusual complications that provide a better understanding of Russell's viper envenomation effects. To further strengthen this, here, we report a case of Russell's viper bite that induced acute abdominal pain, which was intensified on day two and conservatively treated under medical supervision. Both Fothergill and Carnett signs were positive for this patient. An ultrasound imaging revealed a dissimilar dense mass, and the abdominal computed tomography scan confirmed rectus sheath haematoma. The clinical management involved the administration of polyvalent antivenom, packed red blood cells, fresh frozen plasma, and platelets. The patient recovered gradually and was discharged from the hospital eight days after the bite. Overall, this case presentation shares an uncommon experience and adds new insights into the complex series of rare pathological events associated with Russell's viper bites in India. The scientific documentation of relatively infrequent entities based on an ongoing living assessment of medical experiences, for example, this rectus sheath haematoma, constitutes valuable guidance for an adequate diagnosis and timely treatment. Essential awareness among clinicians and further research on understanding the molecular relationship between Russell's viper venom and rectus sheath haematoma will improve patient outcomes and understanding of this condition, respectively.

Hump-Nosed Pit Viper Envenomation in Western Coastal India: A Case Series

The hump-nosed pit viper (HNPV) has historically been considered less medically significant, causing local envenomation, renal injury, and coagulopathy; however, now, it is known to cause life-threatening complications. We describe the clinical presentation, treatment, and complications of 3 confirmed HNPV bites from the state of Karnataka (southwest coastal India). Patient 1, an 88-y-old woman, reported with the live specimen and developed venom-induced consumption coagulopathy (VICC) and thrombotic microangiopathy leading to acute kidney injury requiring blood product transfusions and dialysis. Patient 2, a 60-y-old woman, reported 3 d after envenomation followed by treatment at another hospital where 30 vials of polyvalent anti-snake venom (ASV) were given. She developed VICC and acute kidney injury requiring dialysis. On Day 9 of treatment, she developed a pontine hemorrhage. She died after a transfer to another treatment center closer to her residence. Patient 3, a 25-y-old man, was brought to our emergency department 6 h after being envenomed. He received topical ayurvedic treatment before arrival. He was unconscious and found to have severe VICC with a massive middle cerebral artery infarct. All 3 patients received Indian polyvalent ASV, which does not cover HNPV envenomation, clearly demonstrating the absence of paraspecificity and neutralization in a clinical setting. To our knowledge, Hypnale hypnale envenomation has not previously been reported from Karnataka state. The diagnosis of HNPV envenomation in a country without snake venom detection kits, under-reporting despite serious complications, financial burdens on rural populations afflicted, and poor outcomes due to the lack of a specific antivenom are discussed.

Clinical features and management of snake bites in 70 dogs in Korea

BACKGROUND

Snakebites remain a devastating and life-threatening environmental hazard. While the management of snakebites has been well described in humans, few clinical data and guidelines exist for dogs, especially in Korea.

OBJECTIVES

This retrospective study evaluated the clinical features of 70 dogs with snakebite wounds in Korea.

METHODS

The medical records of 72 dogs that presented to three animal hospitals from June 2008 to July 2021 were reviewed; among these, 70 dogs that met the inclusion criteria were enrolled. Their signalment, history, clinical signs, physical examination, blood analysis, treatment, and prognosis were also evaluated.

RESULTS

Of 70 dog owners, 35 (50%) witnessed the bite, with a mean time between bite and hospital presentation of 9.7 ± 4.1 h in 58 dogs. Blood smears were evaluated in 45 dogs, of which 28 (62%) showed echinocytosis. Anemia and acute kidney injury were found in 21 (29%) and 2 dogs (3%), respectively. A total of 37 dogs (53%) were hospitalized, 5 (7%) of which died.

CONCLUSIONS

The most significant finding was the high prevalence of echinocytosis. The data from this retrospective study could inform the management of dogs bitten by snakes in Korea.

A comparative cross-reactivity and paraspecific neutralization study on Hypnale hypnale, Echis carinatus, and Daboia russelii monovalent and therapeutic polyvalent anti-venoms

Envenoming by the hump-nosed pit viper (Hypnale hypnale) raises concern as it inflicts significant debilitation and death in the Western Ghats of India and in the adjacent island nation of Sri Lanka. In India, its medical significance was realized only during 2007 due to its misidentification as Echis carinatus and sometimes as Daboia russelii. Of late, several case reports have underlined the ineptness of the existing polyvalent anti-venom therapy against H. hypnale envenoming. Currently, H. hypnale bite has remained dreadful in India due to the lack of neutralizing anti-venom therapy. Hence, this study was undertaken to establish a systematic comparative, biochemical, pathological, and immunological properties of Sri Lankan H. hypnale venom alongside Indian E. carinatus, and D. russelii venoms. All three venoms differed markedly in the extent of biochemical activities including proteolytic, deoxyribonuclease, L-amino acid oxidase, 5'-nucleotidase, hyaluronidase, and indirect hemolytic activities. The venoms also differed markedly in their pathological properties such as edema, hemorrhage, myotoxic, cardiotoxic, and coagulant activities. The venoms showed stark differences in their protein banding pattern. Strikingly, the affinity-purified rabbit monovalent anti-venoms prepared against H. hypnale, E. carinatus, and D. russelii venoms readily reacted and neutralized the biochemical and pathological properties of their respective venoms, but they insignificantly cross-reacted with, and thus failed to show paraspecific neutralization of any of the effects of the other two venoms, demonstrating the large degree of variations between these venoms. Further, the Indian therapeutic polyvalent anti-venoms from VINS Bioproducts, and Bharath Serums and Vaccines failed to protect H. hypnale venom-induced lethal effects in mice.

A simple mortality risk prediction score for viper envenoming in India (VENOMS): A model development and validation study

BACKGROUND

Snakebite is a neglected problem with a high mortality in India. There are no simple clinical prognostic tools which can predict mortality in viper envenomings. We aimed to develop and validate a mortality-risk prediction score for patients of viper envenoming from Southern India.

METHODS

We used clinical predictors from a prospective cohort of 248 patients with syndromic diagnosis of viper envenoming and had a positive 20-minute whole blood clotting test (WBCT 20) from a tertiary-care hospital in Puducherry, India. We applied multivariable logistic regression with backward elimination approach. External validation of this score was done among 140 patients from the same centre and its performance was assessed with concordance statistic and calibration plots.

FINDINGS

The final model termed VENOMS from the term "Viper ENvenOming Mortality Score included 7 admission clinical parameters (recorded in the first 48 hours after bite): presence of overt bleeding manifestations, presence of capillary leak syndrome, haemoglobin <10 g/dL, bite to antivenom administration time > 6.5 h, systolic blood pressure < 100 mm Hg, urine output <20 mL/h in 24 h and female gender. The lowest possible VENOMS score of 0 predicted an in-hospital mortality risk of 0.06% while highest score of 12 predicted a mortality of 99.1%. The model had a concordance statistic of 0·86 (95% CI 0·79-0·94) in the validation cohort. Calibration plots indicated good agreement of predicted and observed outcomes.

CONCLUSIONS

The VENOMS score is a good predictor of the mortality in viper envenoming in southern India where Russell's viper envenoming burden is high. The score may have potential applications in triaging patients and guiding management after further validation.

Clinical and Epidemiological Characteristics of Acute Poisoning in Children in Southwestern China: A Review of 1755 Cases from 2014 to 2020

Purpose

Acute poisoning is a major cause of disability and death in children, but there is a lack of large-scale and multicenter epidemiological data on acute poisoning in children.

Patients and Methods

The current study was a retrospective analysis of clinical data from 1755 children aged 0 to 14 years who were hospitalized between 01 January 2014 and 31 December 2020 in southwestern China.

Results

Acute poisoning was common in childhood, particularly in early childhood (607; 34.6%) and preschool (655; 37.3%), and most cases occurred in rural areas (1191; 67.9%). It was more common in boys (934; 53.2%) than in girls (821; 46.8%). In urban areas, poisoning was mainly caused by drugs (266; 47.2%), chemical agents (59; 10.5%), and alcohol (54; 9.6%). In rural areas, it was mainly caused by pesticides (620; 52.1%) and medications (213; 17.9%), the route of poisoning was usually the digestive tract (1671; 95.2%), in most cases the poisoning was accidental (1618; 92.3%), and pesticides (659; 37.5%) and medications (479; 27.3%) predominated. After timely treatment, the majority of patients had no substantial organ damage, sequelae, or disabilities, and mortality was low (17; 1.0%).

Conclusion

Acute poisoning is a frequent accident in childhood, mainly in infants and preschool children, mostly in rural areas, and poisoning mostly occurs via the digestive tract. Family and community education should be conducted to prevent poisoning.

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Snake bite associated with acute kidney injury

Acute kidney injury (AKI) is a well-known life-threatening systemic effect of snake envenomation which commonly happens secondary to snake bites from families of Viperidae and Elapidae. Enzymatic toxins in snake venom result in injuries to all kidney cell types including glomerular, tubulo-interstitial and kidney vasculature. Pathogenesis of kidney injury due to snake envenomation includes ischaemia secondary to decreased kidney blood flow caused by systemic bleeding and vascular leakage, proteolytic degradation of the glomerular basement membrane by snake venom metalloproteinases (SVMPs), deposition of microthrombi in the kidney microvasculature (thrombotic microangiopathy), direct cytotoxic action of venom, systemic myotoxicity (rhabdomyolysis) and accumulation of large amounts of myoglobin in kidney tubules. Clinical features of AKI include fatigue, loss of appetite, headache, nausea, vomiting, oliguria and anuria. Monitoring of blood pressure, fluid balance, serum creatinine, blood urea nitrogen and serum electrolytes is useful in managing AKI induced by snake envenomation. Early initiation of anti-snake venom and early diagnosis of AKI are always desirable. Biomarkers which will help in early prediction of AKI are being explored, and current studies suggest that urinary clusterin, urinary neutrophil gelatinase-associated lipocalin, and serum cystatin C may play an important clinical role in the future. Apart from fluid and electrolyte management, kidney support including early and prompt initiation of kidney replacement therapy when indicated forms the bedrock in managing snake bite-associated AKI. Long-term follow-up is important because of chances of progression towards CKD.

Capillary leak syndrome induced by the venoms of Russell's Vipers (Daboia russelii and Daboia siamensis) from eight locales and neutralization of the differential toxicity by three snake antivenoms

Snakebite envenomation caused by the Western and Eastern Russell's Vipers (Daboia russelii and Daboia siamensis) may potentially induce capillary leak syndrome (CLS), while the use of antivenom in treating this has not been well examined. This study investigated the CLS-inducing toxicity of Russell's Viper venoms from various sources and examined the neutralization activity of regionally available antivenoms, using a newly devised mouse model. D. russelii venoms demonstrated a more consistent vascular leakage activity (76,000-86,000 CLS unit of vascular leak index, a function of the diameter and intensity of Evans Blue dye extravasation into dermis) than D. siamensis venoms (33,000-88,000 CLS unit). Both species venoms increased hematocrits markedly (53-67%), indicating hemoconcentration. Regional antivenoms (DsMAV-Thailand, DsMAV-Taiwan, VPAV-India) preincubated with the venoms effectively neutralized the CLS effect to different extents. When the antivenoms were administered intravenously post-envenomation (challenge-rescue model), the neutralization was less effective, implying that CLS has a rapid onset that preceded the neutralizing activity of antivenom, and/or the antivenom has limited biodistribution to the venom's inoculation site. In conclusion, Russell's Viper venoms of both species from various locales induced CLS in mice. Antivenoms generally had limited efficacy in neutralizing the CLS effect. Innovative treatment for venom-induced CLS is needed.

Retrospective review of case records of snakebite presenting to a single tertiary care centre over a 5-year period

Background Snakebite is a disease of the poor, and hospitals catering to these individuals are often resource-constrained. Lack of electronic medical records in these resource-limited settings makes the capture of data even harder. Methods Before establishing a snakebite registry in the region, we did a retrospective case record review of all snakebite victims (n=3229) over 5 years who presented to a single tertiary care centre, catering to one of the largest number of snakebite victims in the country. Results Of the 451 cases, 262 (58.1%) presented to the emergency department within 2 hours of the bite. In 170 instances, the snake was brought along and the species of the snake was recorded. Russell's viper was the most common (130; 76.5%). Blood products were used in 237 (52.5%) patients. Acute kidney injury occurred in 165 (36.6%) patients, of whom 37 (8.2%) required dialysis. The mean (SD) duration of hospital admission was 10.5 (7.4) days. There was a significant correlation between number of snakebites with rainfall and humidity. One hundred and seven cases (3.3%) of snakebite resulted in mortality. A majority of mortality records were not available (88%; 94/107), rendering us incapable of doing reliable mortality data correlations or interpretation. Conclusion Viperidae bites predominate in the region, with renal injury being the most common cause for morbidity. Region-specific, prospective snakebite mapping could be a cost-effective strategy that might help in vulnerability analysis of the region. A multi-centric region-specific snakebite registry encompassing not just the clinico-epidemiological characteristics of snakebite victims, but also the demographic data, the pre-hospital care and local remedial practices, geospatial distribution, anti-snake venom and blood product usage, will help in developing better healthcare strategies for snakebite victims in India.

Hypnale coagulopathy: snake envenomation of a different kind

Hypnale hypnale is a small pit viper that is known as the hump-nosed pit viper (HNV) or 'Merrem's hump-nosed pit viper' and is endemic to Sri Lanka and the Western Ghats of South India. Previously, it was thought that this viper bite would result in mild systemic or local envenomation, however, we now know that HNV bites could cause severe systemic toxicity and mortality. The most common systemic toxicity of this viper envenomation is coagulopathy, which is known as 'Hypnale coagulopathy'. Hypnale coagulopathy is quite different from the haemotoxicity caused by other vipers. In this paper, an effort has been made to discuss the unique and unpredictable nature of this coagulopathy due to Hypnale envenomation.

Chronic health effects and cost of snakebite

The burden of disability among survivors and the socio-economic impact of snakebite have not been adequately researched. We reviewed original research articles, case reports and small case series relating to chronic physical, mental and psycho-social disability and economic burden of snakebite. Both physical and psychological health problems seem common in snakebite survivors and can lead to disability and loss of productivity. Chronic physical health effects, musculoskeletal disability being the commonest, can be largely attributed to limited and delayed access to optimal treatment of acute envenoming. The economic burden is considerable, and includes health system costs, out-of-pocket expenditure and opportunity costs, with regional variations. Health systems should be more responsive to needs and circumstances of bite victims, and a more holistic approach should be developed in the treatment of snakebite which incorporates the management of chronic health effects.

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Limited attention has been paid to chronic disability and the socio-economic impact of snakebite.

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Physical and psychological health problems occur in snakebite survivors leading to disability and loss of productivity.

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Chronic health effects can be largely attributed to limited and delayed access to optimal treatment of acute envenoming.

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Economic burden includes health system costs, out-of-pocket expenditure and opportunity costs.

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Health systems should be responsive to needs and circumstances of bite victims including care of chronic health effects.

Ambispective study of clinical picture, management practices and outcome of snake bite patients at tertiary care centre in Northern India

Background

Snakebite is a common but neglected public health problem of tropical & subtropical regions worldwide. This study was conducted to look into profile, first aid measures, management strategy and outcomes of snake bite patients.

Methods

This was an ambispective study conducted in the Department of Medicine & Emergency Medicine at AIIMS, New Delhi from June 2011 to May 2017 and enrolled 54 patients. In retrospective part 33 case records of snake bite patients were retrieved and in prospective part 21 patients were recruited. All relevant information including demographic parameters, first aid measures, clinical and laboratory profile and outcomes were recorded in pre made proformas. All data were analysed using IBM Stata version 13 and Microsoft Excel 2011.

Results

Majority of patients were male, and the mean age was 27.6 years. Maximum numbers of bites 34 (63%) happened in the rainy season and Krait was the most common culprit species. Neurological manifestations were most common (70.4%) followed by haematological. Most common complication was ventilatory failure (78.6%), and median dose of ASV was 20 vials. Forty-nine (90.7%) patients were discharged successfully. There was significant association of sepsis and shock with non survivors of snake bite with respective P values of 0.02 and 0.007.

Conclusion

Neurotoxic snake bite (70.4%) was the most common type of envenomation. Most common complication was ventilatory failure and majority of patient (90.7%) successfully discharged. Sepsis and shock were significantly associated with non survivors of snake bite.

Integrating human behavior and snake ecology with agent-based models to predict snakebite in high risk landscapes

Snakebite causes more than 1.8 million envenoming cases annually and is a major cause of death in the tropics especially for poor farmers. While both social and ecological factors influence the chance encounter between snakes and people, the spatio-temporal processes underlying snakebites remain poorly explored. Previous research has focused on statistical correlates between snakebites and ecological, sociological, or environmental factors, but the human and snake behavioral patterns that drive the spatio-temporal process have not yet been integrated into a single model. Here we use a bottom-up simulation approach using agent-based modelling (ABM) parameterized with datasets from Sri Lanka, a snakebite hotspot, to characterise the mechanisms of snakebite and identify risk factors. Spatio-temporal dynamics of snakebite risks are examined through the model incorporating six snake species and three farmer types (rice, tea, and rubber). We find that snakebites are mainly climatically driven, but the risks also depend on farmer types due to working schedules as well as species present in landscapes. Snake species are differentiated by both distribution and by habitat preference, and farmers are differentiated by working patterns that are climatically driven, and the combination of these factors leads to unique encounter rates for different landcover types as well as locations. Validation using epidemiological studies demonstrated that our model can explain observed patterns, including temporal patterns of snakebite incidence, and relative contribution of bites by each snake species. Our predictions can be used to generate hypotheses and inform future studies and decision makers. Additionally, our model is transferable to other locations with high snakebite burden as well.

A therapeutic combination of two small molecule toxin inhibitors provides broad preclinical efficacy against viper snakebite

Snakebite is a medical emergency causing high mortality and morbidity in rural tropical communities that typically experience delayed access to unaffordable therapeutics. Viperid snakes are responsible for the majority of envenomings, but extensive interspecific variation in venom composition dictates that different antivenom treatments are used in different parts of the world, resulting in clinical and financial snakebite management challenges. Here, we show that a number of repurposed Phase 2-approved small molecules are capable of broadly neutralizing distinct viper venom bioactivities in vitro by inhibiting different enzymatic toxin families. Furthermore, using murine in vivo models of envenoming, we demonstrate that a single dose of a rationally-selected dual inhibitor combination consisting of marimastat and varespladib prevents murine lethality caused by venom from the most medically-important vipers of Africa, South Asia and Central America. Our findings support the translation of combinations of repurposed small molecule-based toxin inhibitors as broad-spectrum therapeutics for snakebite.

Endocrine and Metabolic Manifestations of Snakebite Envenoming

Snakebite envenoming is a neglected, public health problem in tropical and subtropical regions. Local tissue necrosis, neurotoxic, and hemo-vasculotoxic effects are well-recognized features, whereas the endocrine and metabolic derangements are not as well known. In addition to contributing to morbidity, some of these manifestations can be potentially life-threatening if not recognized early. The most prominent endocrine manifestation is hypopituitarism (HP), which can manifest acutely or remain asymptomatic and present years later. Unexplained recurrent hypoglycemia and refractory hypotension are early clinical clues to suspect corticotroph axis involvement in acute settings. Chronic pituitary failure may present, like Sheehan's syndrome, several years after the bite. The occurrence of acute kidney injury, capillary leak syndrome, and disseminated intravascular coagulation are predictors of HP. Adrenal hemorrhages are documented in autopsy series; however, primary adrenal insufficiency is very rare and confounded by the presence of HP. Hyponatremia, hypokalemia or hyperkalemia, and dysglycemia can occur, but the mechanisms involved are only partially understood. Awareness, a high index of suspicion, correct interpretation of hormonal parameters, and timely treatment of these abnormalities can be lifesaving.

Hematotoxic Snakebite Victim with Trauma: The Role of Guided Transfusion, Rotational Thromboelastometry, and Tranexamic Acid

Hematotoxic snake bite is a leading cause of mortality in South India. However, it is rare for the emergency physician to encounter a patient with trauma associated with snakebite. Management of such a patient differs substantially from the routine management of either a trauma patient or a snakebite victim. A 59-y-old man was bitten by a snake, after which he lost consciousness, fell, and sustained facial trauma. He was rushed to the emergency department within 30 min and was discovered to have ongoing oromaxillofacial bleeding. His respiratory distress and gasping respirations warranted orotracheal intubation and ventilation. He was treated with anti-snake venom and underwent viscoelastometry-guided transfusion to correct coagulopathy. Hemostasis was achieved after administration of tranexamic acid and bilateral posterior nasal packing. Imaging studies revealed craniomaxillofacial trauma with intracranial hemorrhage. He underwent a delayed mandibular repair. Judicious, guided fluid management, adequate nutrition, and prompt weaning off the ventilator allowed early discharge of the patient from the hospital. The minimal weakness present in his left lower limb at the time of discharge had improved by the time of follow-up. This report shows the utility of early and rapid anti-snake venom in envenomated victims with coagulopathy. The role of cryoprecipitate, tranexamic acid, and viscoelastometric testing needs further exploration in specific hematotoxic snakebites.

Bedside Coagulation Tests in Diagnosing Venom-Induced Consumption Coagulopathy in Snakebite

Venom-induced consumption coagulopathy is the most important systemic effect of snake envenoming. Coagulation tests are helpful to accurately and promptly diagnose venom-induced consumption coagulopathy and administer antivenom, which is the only specific treatment available. However, bedside clotting tests play a major role in diagnosing coagulopathy in low-income settings, where the majority of snakebites occur. We conducted a literature search in MEDLINE^® from 1946 to 30 November 2019, looking for research articles describing clinical studies on bedside coagulation tests in snakebite patients. Out of 442 articles identified, 147 articles describing bedside clotting assays were included in the review. Three main bedside clotting tests were identified, namely the Lee–White clotting test, 20-min whole blood clotting time and venous clotting time. Although the original Lee–White clotting test has never been validated for snake envenoming, a recently validated version has been used in some South American countries. The 20-min whole blood clotting time test is the most commonly used test in a wide range of settings and for taxonomically diverse snake species. Venous clotting time is almost exclusively used in Thailand. Many validation studies have methodological limitations, including small sample size, lack of case-authentication, the inclusion of a heterogeneous mix of snakebites and inappropriate uses of gold standard tests. The observation times for bedside clotting tests were arbitrary, without proper scientific justification. Future research needs to focus on improving the existing 20-min whole blood clotting test, and also on looking for alternative bedside coagulation tests which are cheap, reliable and quicker.

The effect of myocardial injury on the clinical course of snake envenomation in South Korea

CONTENT

This study investigated the incidence, progression and clinical course of myocardial injury-related snake envenomation in South Korea. In addition, this study evaluated whether antivenom guidelines are appropriate to control envenomation in patients with myocardial injury.

METHODS

The study included 198 patients who received antivenom after a snakebite, and they were divided into two groups according to evidence of myocardial injury (defined as elevated troponin I or ischemic change on electrocardiogram) at presentation. Data including serial troponin I, echocardiogram/coronary angiogram findings, the clinical course, and treatment were collected and analyzed.

RESULTS

The incidence of myocardial injury at presentation was 15.2%. The troponin I level was 0.11 (0.07-0.56) ng/ml at presentation and tended to decrease over 24 h. Echocardiograms revealed neither regional wall motion abnormalities nor left ventricular dysfunction in 15 of 17 patients, while two patients showed signs of coronary artery stenosis on echocardiograms and coronary angiograms. However, compared with patients without myocardial injury, patients with myocardial injury had a higher frequency of systemic envenomation complications, including bleeding, respiratory failure, hypotension, acute kidney injury, thrombocytopenia and venom-induced consumption coagulopathy (VICC). The patients with myocardial injury at presentation needed significantly more frequent and larger doses of antivenom than indicated by the initial severity of envenomation. Multivariate analysis showed that myocardial injury was associated with the need for additional antivenom administration after initial administration.

DISCUSSION AND CONCLUSION

Myocardial injury is not uncommon after snake envenomation in Korea. Although myocardial injury itself seems to be benign, the clinical course of patients with myocardial injury is complicated, and myocardial injury is associated with the need for additional antivenom administration. The optimal use of antivenom to control envenomation in patents with myocardial injury after snake envenomation in South Korea should be established.

Trends in snakebite deaths in India from 2000 to 2019 in a nationally representative mortality study

The World Health Organization call to halve global snakebite deaths by 2030 will require substantial progress in India. We analyzed 2833 snakebite deaths from 611,483 verbal autopsies in the nationally representative Indian Million Death Study from 2001 to 2014, and conducted a systematic literature review from 2000 to 2019 covering 87,590 snakebites. We estimate that India had 1.2 million snakebite deaths (average 58,000/year) from 2000 to 2019. Nearly half occurred at ages 30-69 years and over a quarter in children < 15 years. Most occurred at home in the rural areas. About 70% occurred in eight higher burden states and half during the rainy season and at low altitude. The risk of an Indian dying from snakebite before age 70 is about 1 in 250, but notably higher in some areas. More crudely, we estimate 1.11-1.77 million bites in 2015, of which 70% showed symptoms of envenomation. Prevention and treatment strategies might substantially reduce snakebite mortality in India.

Extensive spontaneous cerebral haemorrhage after Russell's viper bite

A 30-year-old man presented with altered sensorium following Russell's viper bite, which was found to be secondary to intracranial hemorrhage secondary to venom-induced consumptive coagulopathy. He was managed conservatively with blood component transfusion and antivenom injection, and successfully discharged.

Clinical and epidemiologic profile of venomous snakebites in Chongqing Wuling mountainous area, western China

BACKGROUND

In China, venomous snakebites are an important medical emergency and cause of hospital admission, but few studies have looked at the clinical and epidemiologic profile of human snakebite victims.

METHODS

We conducted a retrospective study of 440 snakebite cases encountered at a single hospital in the Chongqing Wuling mountainous area of western China from July 2004 to August 2018. Data were collected from the electronic medical record system.

RESULTS

The majority of bite victims were male (58.4%), 41-60 y of age (37.9%) and the bites occurred during the daytime (51.1%) in July-September (62.5%). The lower limbs were the most vulnerable sites to snakebites (73.9%). The most common local toxicity consisted of pain (86.1%), oedema (78.4%) and bleeding (35.9%). Of the systemic toxicities, haematuria (14.3%) and ophthalmoplegia (9.5%) were common. The majority (86.4%) of individuals presented to the hospital within 6 h.

CONCLUSIONS

This study describes the clinical and epidemiologic profile of venomous snakebites in the Chongqing Wuling mountainous area of western China. Multicentre prospective studies were needed in the entire country of China.

Impact of Naja nigricollis Venom on the Production of Methaemoglobin

Snakebite envenomation is an affliction currently estimated to be killing upwards of 100,000 people annually. Snakebite is associated with a diverse pathophysiology due to the magnitude of variation in venom composition that is observed worldwide. The haemolytic (i.e., lysis of red blood cells) actions of snake venoms are well documented, although the direct impact of venoms on haemoglobin is not fully understood. Here we report on the varied ability of a multitude of snake venoms to oxidise haemoglobin into methaemoglobin. Moreover, our results demonstrate that the venom of an elapid, the black necked spitting cobra, Naja nigricollis, oxidises oxyhaemoglobin (Fe²⁺) into methaemoglobin (Fe³⁺) in a time- and concentration-dependent manner that is unparalleled within the 47 viper and elapid venoms evaluated. The treatment of venom with a reducing agent, dithiothreitol (DTT) is observed to potentiate this effect at higher concentrations, and the use of denatured venom demonstrates that this effect is dependent upon the heat-sensitive proteinaceous elements of the venom. Together, our results suggest that Naja nigricollis venom appears to promote methaemoglobin production to a degree that is rare within the Elapidae family, and this activity appears to be independent of proteolytic activities of venom components on haemoglobin.

Exploring circulatory shock and mortality in viper envenomation: a prospective observational study from India

BACKGROUND

Viper envenomation contributes to nearly 50% of snake-bite deaths in India, chiefly due to circulatory shock. The mechanisms leading to circulatory shock include bleeding, capillary leak syndrome (CLS) and myocardial depression. Pituitary-adrenal axis involvement in circulatory shock, though described, has not been fully elucidated.

AIM

To identify predictors of circulatory shock and mortality in viper envenomation and explore the role of pituitary-adrenal axis in circulatory shock.

DESIGN

Prospective hospital-based observational study.

METHODS

Once a syndromic diagnosis of viper envenomation was made, relevant clinical and laboratory data were collected. Serum cortisol was estimated in those with circulatory shock. Post-mortem examination of pituitary, kidneys and adrenals was performed. Adjusted odds-ratios were calculated for respective risk-factors for shock and mortality using multivariable logistic regression with backward elimination strategy.

RESULTS

Of 248 patients of viper envenomation treated at our hospital, circulatory shock was present in 19% and in-hospital mortality was 23%. CLS, circulatory shock, bleeding and requirement of > 20 vials of antivenom predicted mortality. Ischaemic and haemorrhagic necrosis of pituitary or adrenals was present in 51% of post-mortem specimens. Disseminated intravascular coagulation (DIC) and CLS were strong predictors of pituitary haemorrhage.

CONCLUSION

Predictors of mortality - bleeding, CLS and requirement of high antivenom doses are warning signs which can alert clinicians to patients who may have poor outcomes. Our study points to a definite role of pituitary-adrenal axis in circulatory shock supports the hypothesis that pituitary involvement in viper envenomation closely resembles Sheehan syndrome. The mechanism of pituitary involvement appears to be a result of increased susceptibility of the swollen gland secondary to CLS and micro thrombi deposition in DIC.