Venom-Induced Consumption Coagulopathy Following Hump-Nosed Pit Viper (Genus: Hypnale) Envenoming in Sri Lanka: Uncertain Efficacy of Fresh Frozen Plasma

Challenges in Snakebite Management in India: Insights from a Physician Survey with Special Focus on Kerala and treatment of bites by Hump-nosed Pit Vipers (Hypnale spp.)

BACKGROUND

India has a high incidence of snakebite-related mortality, making effective snakebite management crucial. This study aimed to explore current practices, challenges, and opportunities for improvement in snakebite management across India.

METHODS

A cross-sectional survey was conducted among physicians in India covering aspects such as scope of practice, snake identification, first aid measures, institutional management, and specific management practices for hump-nosed pit viper (Hypnale hypnale) bites. The survey included 37 questions across 5 sections, with data collected via emails, professional networks, and online platforms. Statistical analysis was performed using SPSS Statistics 23 (IBM Corp, Armonk, NY), and manual thematic analysis was applied to open-ended responses.

RESULTS

The survey revealed a discrepancy between physicians' confidence and accuracy in snake identification, with some still reporting outdated first aid and treatment practices. Despite recognizing the importance of snake species identification, a significant portion of respondents incorrectly identified the snakes. The study highlighted variability in institutional practices for snakebite management, such as administering prophylactic antibiotics and tetanus prophylaxis and monitoring periods for asymptomatic patients. In managing H hypnale viper bites, a demand for specific guidelines and a monovalent antivenom was evident because the current polyvalent antivenom is ineffective for this species.

CONCLUSIONS

The survey emphasizes the need for improved training in snake identification, standardized treatment protocols, and the development of region-specific antivenoms. It emphasizes the necessity of updating guidelines to address the unique challenges of snakebite management in India, particularly for species not covered by existing antivenoms.

Antivenom ineffectiveness in Echis carinatus sochureki envenoming: a five-year, single-centre experience from India

BACKGROUND

Snakebite is a neglected tropical disease that causes significant morbidity and mortality in India. In this study, we describe the clinical characteristics and outcomes of Echis carinatus sochureki envenoming from Western Rajasthan. We document the clinical ineffectiveness of the currently available Indian polyvalent antivenom in managing E. c. sochureki envenoming.

METHODS

In this ambispective study, conducted from 14 April 2019 to 15 April 2024, we enrolled all patients presenting to our emergency department at a tertiary care centre in Jodhpur, Rajasthan, with a history of snakebite. After they provided informed consent, the demographic details, bite geo-location, bite-to-antivenom time, antivenom dose, coagulation profile, mortality and duration of hospital stay of those patients with E. c. sochureki envenoming were recorded.

RESULTS

Of 210 patients screened, 105 had E. c. sochureki envenoming, 103 venom-induced consumption coagulopathy, 36 (34.3%) local bleeding and 55 (52.3%) systemic bleeding. The median bite-to-antivenom time was 2 (IQR: 1.13-4.0) h. The median antivenom dose was 22 (IQR: 10-30) vials. Of 92 patients who received antivenom, 63 (68.4%) were unresponsive. Total antivenom dose and geographical location (West zone) were significant predictors of antivenom unresponsiveness. Fifty-three of 70 patients (75.7%) had delayed hypofibrinogenaemia. The mean hospital stay was 8.3±7.1 d with nine (8.6%) mortalities.

CONCLUSIONS

Our study highlights the alarming finding of poor antivenom response to E. c. sochureki envenoming, with significant clinical bleeding and delayed coagulopathy. There is an urgent need for region-specific antivenom in Western India.

Snakebite-associated acute kidney injury in South Asia: narrative review on epidemiology, pathogenesis and management

Snakebite-associated acute kidney injury (AKI) poses a significant health burden in the South Asia region, resulting in considerable morbidity and mortality. Multiple factors contribute to the pathogenesis of AKI following snakebites, including hypotension, intravascular haemolysis, disseminated intravascular coagulation, rhabdomyolysis, thrombotic microangiopathy (TMA) and direct nephrotoxicity. Clinical features manifest as anuria, oliguria, haematuria, abdominal pain and hypertension. Diagnosis is supported by elevated serum creatinine levels and urine output monitoring. Renal histology studies revealed a spectrum of lesions, including acute tubular necrosis, renal cortical necrosis, glomerulonephritis and TMA. Management strategies centre around timely administration of antivenom, fluid and electrolyte balance and dialysis to improve renal outcomes. While dialysis has demonstrated efficacy in reducing AKI-related mortality rates, the use of fresh frozen plasma and therapeutic plasma exchange may be the subject of some controversy. Understanding the pathophysiological link between coagulopathy, TMA and AKI is important for tailoring effective treatment approaches. Species-specific randomized controlled trials are imperative to evaluate targeted interventions. In tackling the complexities of snakebite-associated AKI and chronic kidney disease, a multidisciplinary approach integrating clinical management with rigorous research efforts is essential. This collaborative endeavour aims to confront the challenges posed by these conditions and improve patient outcomes in the affected regions.

Haemotoxicity of snakes: a review of pathogenesis, clinical manifestations, novel diagnostics and challenges in management

Haemotoxicity is the most common complication of systemic envenoming following snakebite, leading to diverse clinical syndromes ranging from haemorrhagic to prothrombotic manifestations. Key haematological abnormalities include platelet dysfunction, venom-induced consumption coagulopathy, anticoagulant coagulopathy and organ-threatening thrombotic microangiopathy. Diagnostic methods include the bedside whole blood clotting test, laboratory coagulation screening and other advanced methods such as thromboelastogram and clot strength analysis. The primary management strategies are venom neutralisation with antivenom and correction of coagulopathy with blood component transfusions, while options such as plasma exchange are utilised in certain cases. Recent advancements in understanding the pathogenesis of haemotoxicity have facilitated the development of new diagnostic and treatment modalities. This review summarises current knowledge on the pathogenesis, diagnosis, clinical and laboratory manifestations and treatment of the haematological effects of snake envenoming. Furthermore, it highlights important challenges concerning diagnosis and management. Addressing these challenges is crucial for achieving the WHO's goal of reducing deaths and disabilities caused by snakebites by 2030.

Acute compartment syndrome leading to fasciotomy, severe morbidity and long-term disabilities following Sri Lankan Green pit viper (Peltopelor trigonocephalus) envenomation

Green pit viper (Peltopelor trigonocephalus) is a medically important endemic snake in Sri Lanka. Its envenoming commonly causes local effects such as pain, swelling, blistering, and lymphadenopathy and rarely causes venom-induced consumption coagulopathy as a systemic effect. Despite its frequent encounters in estates, commonly tea and cinnamon plantations, reports of envenoming are rare and limited to nine reports in the literature. An extensive literature review confirms no previous reports of compartment syndrome following Sri Lankan Green pit viper bites. We report two cases of acute compartment syndrome leading to fasciotomy, of which, in addition, case 1 patient developed venom-induced consumption coagulopathy.

Protobothrops jerdonii (Jerdon's pit viper) and Protobothrops himalayanus (Himalayan lance-headed pit viper) bites: Clinical report on envenomings from North-East India, managed through remote consultation by a national-level Poison control center

Members of the genus Protobothrops are amongst the more than twenty-eight range-restricted Indian pit viper species. Their bites and envenomings are rarely documented from India. Pit viper envenomings can be challenging to treat in the Indian setting, since available antivenoms do not satisfactorily neutralize their venoms. Herein, we present the first Indian reports on bites and envenoming by Protobothrops jerdonii and Protobothrops himalayanus resulting in local effects, coagulopathy and acute kidney injury in the case of the former and possible mild, isolated coagulopathy in the case of the latter; and discuss management-related challenges in the context of absent specific antivenoms.

Long-term health manifestations of hump-nosed pit viper (Genus: Hypnale) bites

INTRODUCTION

The hump-nosed pit viper (Genus: Hypnale) is a highly medically significant snake in Sri Lanka, responsible for the majority of venomous snakebites (22-77%). They are found throughout Sri Lanka and the Western Ghats region of India. The venom can lead to two types of effects: acute and long-term. Acutely, bites often result in local symptoms, with less common systemic effects such as acute kidney injury, venom-induced consumption coagulopathy, and thrombotic microangiopathy.

METHODS

We conducted a prospective observational study at Teaching Hospital Ratnapura, Sri Lanka, spanning six years, starting in June 2015. Patients bitten by hump-nosed pit vipers were followed up for two years, with assessments every three months to identify long-term effects. Data was gathered through interviewer-administered questionnaires.

RESULTS

Out of 728 patients bitten by hump-nosed pit vipers, 22 (3%) were lost to follow-up. Forty-four (6.2%) experienced long-term effects, including chronic kidney disease (24; 3.4%), chronic wounds (five; 0.7%), amputations (five; 0.7%), fasciotomy-related wounds (four; 0.6%), and psychological illnesses (four; 0.6%). There were nine (1.3%) deaths in this group. Among those with chronic effects, 27 (61%) were males, and 17 (39%) were females, with ages ranging from 29 to 82 years (mean 57.6 years). The time it took to diagnose acute kidney injury from the snakebite was 18 h (interquartile range: 15-23.5 h), while the time to diagnose chronic kidney disease was 69 days (interquartile range: 64-74.75 days). In these patients, the estimated glomerular filtration rate was 29.3 mL/min/1.73 m2 (interquartile range: 14-50.75 mL/min/1.73 m2). Among the patients who did not develop long-term complications (662; 91%) 660 (90.7%) experienced local effects, and 82 (11.3%) developed systemic manifestations, including acute kidney injury in 60 (8%) and coagulopathy in 35 (5%).

CONCLUSION

Following hump-nosed pit viper bites, a subset of patients may experience long-term health complications, including chronic kidney disease, chronic ulcers, amputations, fasciotomy-related wounds, and psychological illnesses, with chronic kidney disease being the most frequently observed among these manifestations.

Epidemiology and clinical features of Hypnale nepa (hump-nosed pit viper) envenoming in Sri Lanka

Sri Lanka homes 3 species of hump-nosed pit vipers including Hypnale Hypnale, H. zara and H. nepa from which, latter 2 are endemic to the country. Even though former 2 are the subject of several publications, no major clinical studies have been done regarding H. nepa bites. As these snakes confine only to central hills of the country, their bites are very rare. The objectives of this study were to describe epidemiological and clinical features of H. nepa bites. A prospective observational study was conducted for patients admitted with H. nepa bites to Teaching Hospital, Ratnapura, Sri Lanka for 5 years commencing from June 2015. Species identification was done using a standard key. There were 14 (3.6%) patients with H. nepa bites of which 9 (64%) were males and 5 (36%) were females. Their age ranged from 20 to 73 years (median 37.5). Seven bites (50%) occurred on lower limbs. Majority of bites (10; 71%) happened at daytime [0600-1759 h] in tea estates (8; 57%). Most patients (8; 57%) were admitted within 1-3 h from bite. Hospital stay was 2.5 days (IQR 2-3). Local envenoming was observed in all patients including local pain and swelling [mild (7; 50%), moderate (5; 36%), severe (2; 14%)], local bleeding (1; 7%) and lymphadenopathy (1; 7%). Nonspecific features were observed in 3 (21%). Systemic manifestations were found in 2 (14%) including microangiopathic haemolytic anaemia and sinus bradycardia. Two (14%) had myalgia. H. nepa bites frequently cause local envenoming. But, rarely systemic manifestations may occur.

A case report of Ovophis monitcola (Mountain pit-viper) envenoming in northeastern India resulting in prolonged coagulopathy

India is home to a diverse spectrum of medically-significant snakes accounting for the world's largest burden of envenoming, morbidity and mortality. Indian polyspecific antivenom is derived from the venom of four snake species (Daboia russelii, Echis carinatus, Naja naja and Bungarus caeruleus), considered to be responsible for the majority of snakebite morbidity and mortality. The treatment of venomous bites from other less-commonly encountered venomous snake species can be challenging. In this report, we describe the case of a 32-year-old male who presented with features of local cytotoxicity and coagulopathy following a bite from Ovophis monitcola (mountain pit-viper) in Nagaland, northeast India. Local and systemic envenoming, confirmed by bedside and laboratory based clotting assays, failed to respond to polyspecific antivenom and venom-induced consumption coagulopathy persisted for 28 days. Remote consultation with a national Poison Control Centre helped establish the responsible snake species and guide appropriate medical management.

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.

The use of rotational thromboelastometry parameters in understanding the coagulopathy following hump-nosed viper (Hypnale spp) bites: a preliminary study

BACKGROUND

Hump-nosed vipers (HNV; Hypnale spp) are one of the medically important venomous snakes in Sri Lanka and South-Western regions of India. The haemostatic dysfunction due to HNV bites is poorly characterized by standard diagnostic tests performed to identify coagulopathy. We aimed to determine the usefulness of rotational thromboelastometry (ROTEM) parameters compared to 20-minute whole blood clotting test (WBCT20) and prothrombin time (PT) in understanding the coagulopathy of HNV bites.

METHODS

Twenty-three HNV snakebite patients in a prospective study of 127 consecutive snakebites were recruited. After recording details of the clinical presentation, PT/international normalized ratio (INR), WBCT20 and ROTEM delta were performed at presentation.

RESULTS

In this preliminary study, none of the patients had clinically apparent bleeding. Coagulopathy was detected by either WBCT20, INR or ROTEM in 13 HNV patients. Eleven had a coagulopathy detectable by ROTEM (either abnormal EXTEM-CT, INTEM-CT or FIBTEM-MCF) but with negative WBCT20. Of them, only two had prolonged INR values. Two patients had positive WBCT20 but with normal ROTEM and INR values. The remaining 10 patients did not show any coagulopathy either by INR, ROTEM or WBCT20.

CONCLUSION

In this preliminary study with small number of sample size, ROTEM parameters appeared to be more sensitive to subtle changes in coagulation compared to WBCT20. The clinical utility of detecting these changes and their usefulness in managing snakebite should be explored further in a larger study.

Epidemiological and clinical features of hump-nosed pit viper (Hypnale hypnale and Hypnale zara) envenoming in children

BACKGROUND

Bites by the hump-nosed pit vipers (HNPV) of the genus Hypnale are the commonest type of venomous snakebites in Sri Lanka. Their bites frequently cause local effects while rarely causing systemic envenoming, that may include acute kidney injury and coagulopathy. There are 3 species of genus Hypnale including H. hypnale, H. zara and H. nepa from which latter two are endemic to Sri Lanka. Virtually all studies on HNPV bites in Sri Lanka are focused on adults except two studies in paediatric group. The aims of this study were to describe the epidemiology and clinical manifestations of HNPV bites in a group of children admitted to a tertiary care hospital in Sri Lanka.

METHODOLOGY/PRINCIPAL FINDINGS

This was a prospective observational study carried out in Teaching Hospital Ratnapura, Sri Lanka over 27 months commencing from May 2020 including all children aged up to 14 years with the history of HNPV bites. There were 40 (56%) HNPV bites, of them 28 (70%) were males. The age was 84 months (50.2-120 months). Majority (n = 21;52.5%) were bitten during day-time (06:00-17:59) in home gardens (n = 20; 50%) on lower limbs (n = 24;60%). Most children (n = 30;75%) were admitted to the medical facility < 4 hours after the snakebite [90 min (40-210 min)] and the hospital stay was 4 days (3-5 days). Local envenoming was observed in 38 patients (95%) and systemic effects developed in 4 patients (10%) as mild coagulopathy. Local effects include local pain (n = 30; 94%), swelling (n = 38;95%), blistering (n = 11;27.5%), necrosis at the site of bite (n = 11; 27.5%), regional lymph node enlargement (n = 8;20%) and local bleeding (n = 4;10%). For the local effects, surgical interventions were needed in 10 children (25%) and 3 (7.5%) of them developed acute compartment syndrome leading to fasciotomy. Leucocytosis (n = 28;78%) and eosinophilia (n = 9;27%) were the prominent laboratory findings. All got recovered except in patients with fasciotomy who got permanent scar.

CONCLUSIONS/SIGNIFICANCE

Hump-nosed pit viper bites mostly cause local effects and rarely systemic envenoming in children. Compartment syndrome is common in children following their bites.

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.

Therapeutic Plasma Exchange for Venom-Induced Thrombotic Microangiopathy Following Hump-Nosed Pit Viper (Genus: Hypnale) Bites: A Prospective Observational Study

INTRODUCTION

-Thrombotic microangiopathy (TMA), which is the triad of acute kidney injury (AKI), microangiopathic hemolytic anemia (MAHA), and thrombocytopenia, is a rare complication of snakebites, and in Sri Lanka, it is commonly seen with hump-nosed pit viper (HNPV) bites.

METHODS

-We conducted a prospective observational study of patients with AKI caused by HNPV bites in Teaching Hospital, Ratnapura, Sri Lanka for 6 y, commencing in June 2015. Some patients with TMA underwent therapeutic plasma exchange (TPE) and some did not. These 2 groups were compared. Statistical analysis was carried out using Minitab 18.1. Data were presented as median (IQR).

RESULTS

-There were 52 (8%) patients with TMA, of whom 21 (45%) were in the TPE group and 26 (55%) were in the non-TPE group. TPE improved time to platelet correction (4 d [IQR, 4-5 d] vs 7 d [IQR, 5-9 d]; P=0.009), time to MAHA correction (5 d [IQR, 3-4 d] vs 7 d [IQR, 6-9 d]; P=0.004), time to prothrombin time (PT)/international normalized ratio (INR) correction (1 d [IQR, 1-2 d] vs 3 d [IQR, 3-4 d]; P=0.003), and time to 20 min whole blood clotting test (WBCT20) correction (2 d [IQR, 1-2 d] vs 3 d [1QR 2-3 d]; P=0.020). Renal recovery was predicted by TPE (P=0.048) and highest creatinine level (P=0.001). There was no association between TPE and dialysis dependency at discharge (P=0.597), length of hospital stay (P=0.220), and the number of dialysis cycles prior to discharge (P=0.540). TPE did not improve the number of blood transfusions (5 packs [IQR, 3-8.5 packs] vs 4 packs [IQR, 0-9 packs]; P=0.290).

CONCLUSIONS

-TPE is effective for TMA in the early correction of platelet counts, MAHA, PT/INR, and WBCT20 in HNPV bites.

Acute ischemic stroke: a rare complication of hump-nosed pit viper (Hypnale spp.) bite: a case report

Background

Hump-nosed pit viper is a medically important deadly venomous snake in Sri Lanka and is the commonest cause of venomous snakebites in the country. It frequently causes local effects and systemic manifestations such as acute kidney injury and coagulopathy that occur in less than 10% of all bites. This also includes some atypical presentations such as thrombotic microangiopathy and myocardial infarction. Currently, no antivenom is available for hump-nosed pit viper bites in Sri Lanka, and patients are managed with supportive treatment. This case illustrates an acute ischemic stroke following a hump-nosed viper bite, which is the second case in the literature.

Case presentation

A 71-year-old a Sinhalese male patient presented with left-sided hemiparesis with mouth deviation on day 2 of hump-nosed viper (Hypnale spp.) bite on the right foot. Non-contrast computed tomography of brain showed right ischemic stroke in internal capsule. He was given antiplatelets and statins and continued supportive treatment including limb physiotherapy and speech therapy. He recovered completely and was discharged on day 4 with clinic follow-up.

Conclusions

Physicians should be aware that ischemic cerebral infarcts may occur following hump-nosed pit viper bites.

Snakebites in Pediatric Patients in Kahramanmaraş: Is Pro-brain Natriuretic Peptide a Prognostic Biomarker for Snakebites?

Background: Snake envenomations are a serious cause of mortality and morbidity in the world.

Aims: This study was conducted to investigate snake bites in pediatric patients in Kahramanmaraş and to determine whether pro-brain natriuretic peptide (proBNP) has a prognostic value in these patients.

Methods: Pediatric patients aged <18 years who presented to the pediatric emergency department with snakebites were reviewed retrospectively. The demographical, clinical, laboratory, treatments, and outcomes data were collected from their medical records. Stage 0 and 1 envenomation was considered as a non-serious complication and stage 2 and 3 envenomation was considered as a serious complication.

Results: A total of 32 pediatric patients, six females and 26 males, between 2016 and 2021, were included in the study. The mean age was 12.52±3.28 years. There were seven patients without serious complications and 25 patients with serious complications. The best cutoff point for proBNP to predict serious complications was found to be ≥272.5 ng∙L^-1 (sensitivity, 83.3%; specificity, 100%, p=0.011). We also detected complex regional pain syndrome in one of our patients.

Conclusions: In this study, proBNP was shown to be predictive of a poor outcome of snakebites. Moreover, complex regional pain syndrome, which is rarely reported in the literature, should be kept in mind during the long-term follow-up of snakebites.

Atypical Hemolytic Uremic Syndrome in a Patient With Bothrops asper Envenomation

Bothrops asper envenomation is common in Colombia and is characterized by local tissue injury and venom-induced consumption coagulopathy (VICC). Rarely, thrombotic microangiopathy is associated with envenomation by this species. The case of a 57-y-old man with B asper bite and envenomation on the left foot is presented. The patient was admitted 8 h after the event and progressively developed edema, hemorrhage at the site of the bite, and hemorrhagic blisters. His coagulation test results (prothrombin and partial thromboplastin times) were prolonged, and his fibrinogen levels were severely reduced. The diagnosis of VICC was made. Administration of Colombian polyvalent viper antivenom controlled the VICC within a few hours. Subsequently, the patient developed severe microangiopathic anemia, thrombocytopenia, and acute kidney injury. A diagnosis of thrombotic microangiopathy was made, and the patient met the criteria for hemolytic uremic syndrome. Management with hemodialysis in addition to therapeutic plasma exchange and replacement with fresh frozen plasma was indicated. The patient's condition resolved 14 d later. To the best of our knowledge, this is the first case of B asper envenomation in which the patient presented with hemolytic uremic syndrome after VICC. A proposal is made regarding the pathogenesis of this chain of events.

Purpura fulminans following hump-nosed pit viper (Hypnale hypnale) envenoming: A rare complication of snakebites

Hump-nosed pit vipers of the genus Hypnale are highly venomous and reputed for the commonest venomous snakebites in Sri Lanka. They frequently cause local manifestations and less commonly cause systemic effects such as acute kidney injury and coagulopathy. There is no antivenom currently available in Sri Lanka for their envenoming. However, more and more complications of Hypnale bites are being recently described. Purpura fulminans, one of the rare complications of snakebites that we report following authentic Hypnale hypnale bite. A 58-year-old female was bitten by a hump-nosed viper and developed bilateral toe gangrenes, ultimately ended up with amputations. She got recovered with loss of toes in both feet for 46 days treatment at hospital.

Clinico-epidemiology of Hypnale zara (hump-nosed pit viper) envenoming in Sri Lanka

BACKGROUND

Hump-nosed vipers of the genus Hypnale are the most common cause of venomous snakebites in Sri Lanka. The genus includes three species: Hypnale hypnale, Hypnale zara and Hypnale nepa. Of them, H. hypnale bites are the most common and are the subject of many publications. The epidemiology and clinical features of bites by the other two species have been less investigated.

METHODS

We conducted a prospective observational study of H. zara bites from January 2015 to June 2020 at the Teaching Hospital, Ratnapura, Sri Lanka. Data were collected for 5.5 years in the wet zone of the island, where the principal investigator did assessment of all patients and the data collection.

RESULTS

H. zara envenoming was confirmed through identification of dead or live snake specimens brought with the patients. Of the 480 patients with proven hump-nosed viper bites, H. zara bites accounted for 105 (22%), including dry bites (n=5 [5%]) and envenoming (n=100 [95%]), with gender distribution of 65 (62%) males and a mean age of 43.1 y. Most bites occurred on the lower limbs (n=71 [68%]) in the daytime (n=69 [66%]) in home gardens (n=45 [43%]). A total of 100 (95%) patients had local manifestations, including pain (n=100 [95%]), swelling (n=100 [95%]), bleeding (n=20 [19%]), bruising (n=11 [10%]), lymphadenopathy (n=10 [9%]), necrosis at the bite site (n=9 [9%]) and blistering (n=8 [8%]). Seven (6.7%) patients showed systemic effects, including acute kidney injury (n=2 [2%]), microangiopathic haemolysis (n=2 [2%]), sinus bradycardia (2 [2%]) and one (1%) each had coagulopathy, thrombotic microangiopathy, Kounis syndrome and ischaemic changes on electrocardiography. Eosinophilia was a significant haematological finding (n=26 [25%]) and 16 (15%) had leucocytosis and 15 (14%) had neutrophilia. Ninety six percent of patients (n=101) recovered. Antivenom is not available for hump-nosed viper bites in Sri Lanka and therefore patients were managed conservatively.

CONCLUSIONS

This study shows that H. zara bites mainly cause local envenoming and rarely systemic effects.

Kounis Syndrome Following Hypnale zara (Hump-Nosed Pit Viper) Bite in Sri Lanka

A 47-y-old man was bitten by a hump-nosed viper (Hypnale zara) and gradually developed retrosternal chest pain associated with ST segment elevation on electrocardiogram. He had normal troponin I levels and no evidence of coagulopathy. Initially, he was managed as having anterior ST elevation myocardial infarction with thrombolysis. Later, because troponin levels were normal, he was suggested to have the type I variant of Kounis syndrome (allergic coronary artery spasm). This was supported by high eosinophil counts in peripheral blood. He was successfully managed with supportive treatment and discharged 6 d after the snakebite. Cardiac complications are rarely reported after hump-nosed viper bites, and clinical reports of coronary vasospasm after snakebites are extremely rare in the literature. This is the first known report of Kounis syndrome after a hump-nosed viper bite.