Clinicopathological spectrum of snake bite-induced acute kidney injury from India

Naja nigricincta nigricincta venom, a murine model. Evaluation of skeletal and cardio-myonecrosis, kidney injury and inflammatory response along with neutralisation efficacy by the SAIMR/SAVP - And EchiTAb-Plus-ICP polyvalent antivenoms

African spitting cobra, Naja nigricincta nigricincta (Zebra snake), envenomation is an important cause of snakebite morbidity and mortality in Namibia. The snake is endemic to central and northern Namibia as well as southern Angola. The venom is mainly cytotoxic, resulting in aggressive dermo-necrosis and often accompanied by severe systemic complications. No specific antivenom exists. Rhabdomyolysis, systemic inflammatory response, haemostatic abnormalities, infective necrotising fasciitis as well as acute kidney failure have been documented. Based on murine models, this study assessed SAVP/SAIMR - and EchiTAb-Plus-ICP polyvalent antivenom neutralisation as well as subdermal necrosis. Additional muscle, cardiac, kidney and lung histology, creatine kinase measurements and post-mortems were performed. An intravenous median lethal dose (LD50) of Naja nigricincta nigricincta venom was determined at 18.4 (CI: 16.3; 20.52) μg and a subdermal lethal dose at 15.3(CI: 12.96; 17.74)μg. The SAIMR/SAVP polyvalent antivenom median effective dose (ED50) was 1.2 ml antivenom/1 mg venom equating to a potency (WHO) of 1 ml antivenom neutralising 0.63 mg venom and approximately 240 ml (24 vials) needed for initial treatment. The ED50 of the EchiTAb-Plus-ICP was 1 ml antivenom/1 mg venom and a potency of 65 mg venom/ml antivenom (3.3 x LD50), estimating 230 ml (23 vials) for treatment. Histology and serology (creatine kinase) evidenced venom induced skeletal myotoxicity, which was not prevented by the antivenoms tested. Cardiac myonecrosis, an inflammatory response, direct venom kidney tubular necrosis and cardio-pulmonary failure were documented.

Acute kidney injury in the tropics

Acute kidney injury in the Tropics is strikingly different from that in developed countries in terms of aetiology and presentation. Moreover, there are radical differences between the developed world and the economically poorer regions within the tropics. Infections are the number one cause leading to significant mortality. This article reviews the most common causes of acute kidney injury in the Tropics and describes its management briefly.

The kidney histopathological spectrum of patients with kidney injury following snakebite envenomation in India: scoping review of five decades

INTRODUCTION

Snakebite is a public health problem leading to about 58,000 deaths every year in India. Kidney injury subsequent to snakebite envenomation is common with a reported prevalence of up to 32%. The current study aims to elucidate the spectrum of kidney histopathology in acute kidney injury (AKI) cases associated with snake bites.

METHODS

We searched seven electronic database studies to identify studies describing the histopathological findings in the kidney with snakebite envenomation. Two reviewers independently conducted titles and abstract screening as well as full-text evaluation for the final inclusion decision. Data were extracted as per the standardized form. We conducted narrative synthesis. Studies done exclusively on autopsy findings, in vitro studies, and case reports were excluded.

RESULTS

We retrieved 1464 studies and finally included 28 studies which met the eligibility criteria in the analysis. Most studies were single-centre and the majority were cross-sectional. Overall we included a total of 534 renal biopsies. Russell's viper bite was the most common cause related to AKI. Acute tubular necrosis was the most common finding followed by acute interstitial nephritis, acute cortical necrosis (ACN), and thrombotic microangiopathy (TMA). Vasculitis changes in vessels were rarely reported. Lesions such as ACN and TMA were associated with poor outcomes.

CONCLUSION

This analysis supports the notion that renal biopsies are important to guide prognosis and increase our knowledge about post-snake bite AKI pathophysiology.

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.

Therapeutic outcome of quercetin nanoparticles on Cerastes cerastes venom-induced hepatorenal toxicity: a preclinical study

Aim: The objective of this study was to investigate the therapeutic potential of quercetin (QT) and QT-loaded poly(lactic-co-glycolic acid) nanoparticles (QT-NPs) on Cerastes cerastes venom-mediated inflammation, redox imbalance, hepatorenal tissue damage and local hemorrhage. Methods: The developed QT-NPs were first submitted to physicochemical characterization and then evaluated in the 'challenge then treat' and 'preincubation' models of envenoming. Results: QT-NPs efficiently alleviated hepatorenal toxicity, inflammation and redox imbalance and significantly attenuated venom-induced local hemorrhage. Interestingly, QT-NPs were significantly more efficient than free QT at 24 h post-envenoming, pointing to the efficacy of this drug-delivery system. Conclusion: These findings highlight the therapeutic potential of QT-NPs on venom-induced toxicity and open up the avenue for their use in the management of snakebite envenoming.

Hemoglobin Casts in Kidney Biopsies: Etiological Spectrum

Intravascular hemolysis, which is the destruction of red blood cells in circulation, can cause acute kidney injury as the hemoglobin released by the lysed cells is toxic to the tubular epithelial cells. We performed a retrospective analysis of 56 cases of hemoglobin cast nephropathy reported at our institution to analyze the etiological spectrum causing this rare disease. The mean patient age was 41.7 (range: 2-72 years), and the male-to-female ratio was 1.8:1. All patients presented with acute kidney injury. The etiologies include rifampicin-induced, snake bite, autoimmune hemolytic anemia, falciparum malarial infection, leptospiral infection, autoimmune hemolytic anemia, sepsis, non-steroidal anti-inflammatory drugs, ingestion of termite oil, heavy metal poisoning, wasp sting, and valvular heart disease with severe mitral regurgitation. We demonstrate a wide spectrum of conditions associated with hemoglobin casts in the kidney biopsy. Hemoglobin immunostain is required to establish the diagnosis.

Current situation of snakebites envenomation in the Neotropics: Biotechnology, a versatile tool in the production of antivenoms

Snakebite envenomation is a neglected tropical disease that affects millions of people around the world with a great impact on health and the economy. Unfortunately, public health programs do not include this kind of disease as a priority in their social programs. Cases of snakebite envenomations in the Neotropics are inaccurate due to inadequate disease management from medical records to the choice of treatments. Victims of snakebite envenomation are primarily found in impoverished agricultural areas where remote conditions limit the availability of antivenom. Antivenom serum is the only Food and Drug Administration-approved treatment used up to date. However, it has several disadvantages in terms of safety and effectiveness. This review provides a comprehensive insight dealing with the current epidemiological status of snakebites in the Neotropics and technologies employed in antivenom production. Also, modern biotechnological tools such as transcriptomic, proteomic, immunogenic, high-density peptide microarray and epitope mapping are highlighted for producing new-generation antivenom sera. These results allow us to propose strategic solutions in the Public Health Sector for managing this disease. Keywords: antivenom, biotechnology, neglected tropical disease, omics, recombinant antibody.

GBD 2019 Snakebite Envenomation Collaborators. Global mortality of snakebite envenoming between 1990 and 2019

Snakebite envenoming is an important cause of preventable death. The World Health Organization (WHO) set a goal to halve snakebite mortality by 2030. We used verbal autopsy and vital registration data to model the proportion of venomous animal deaths due to snakes by location, age, year, and sex, and applied these proportions to venomous animal contact mortality estimates from the Global Burden of Disease 2019 study. In 2019, 63,400 people (95% uncertainty interval 38,900-78,600) died globally from snakebites, which was equal to an age-standardized mortality rate (ASMR) of 0.8 deaths (0.5-1.0) per 100,000 and represents a 36% (2-49) decrease in ASMR since 1990. India had the greatest number of deaths in 2019, equal to an ASMR of 4.0 per 100,000 (2.3-5.0). We forecast mortality will continue to decline, but not sufficiently to meet WHO's goals. Improved data collection should be prioritized to help target interventions, improve burden estimation, and monitor progress.

The Middle Eastern Cousin: Comparative Venomics of Daboia palaestinae and Daboia russelii

Among the medically most important snakes in the world, the species belonging to the genus Daboia have been attributed to the highest number of human envenomings, deaths and disabilities. Given their significant clinical relevance, the venoms of Russell's vipers (D. russelii and D. siamensis) have been the primary focus of research. In contrast, the composition, activity, ecology and evolution of venom of its congener, the Palestine viper (D. palaestinae), have remained largely understudied. Therefore, to unravel the factors responsible for the enhanced medical relevance of D. russelii in comparison to D. palaestinae, we comparatively evaluated their venom proteomes, biochemical activities, and mortality and morbidity inflicting potentials. Furthermore, the synthesis and regulation of venom in snakes have also remained underinvestigated, and the relative contribution of each venom gland remains unclear. We address this knowledge gap by sequencing the tissue transcriptomes of both venom glands of D. palaestinae, and comparatively evaluating their contribution to the secreted venom concoction. Our findings highlight the disparity in the venom composition, function and toxicities of the two Daboia species. We also show that toxin production is not partitioned between the two venom glands of D. palaestinae.

Development of Wunderlich syndrome following a Russell's viper bite

Snakebite envenomation is a high priority neglected tropical disease that predominantly affects rural communities living in developing countries. Due to myriad of complications including coagulopathies, neurotoxicity, nephrotoxicity and local tissue destruction, treating snakebite victims is a major challenge for clinicians. Russell's viper (Daboia russelii) is one of the 'Big Four' venomous snakes in India, and it is responsible for the most snakebite-induced deaths and disabilities. Acute kidney injury occurs frequently following Russell's viper bites and it is a critical factor contributing to disabilities, deaths and excessive treatment costs. In addition to commonly observed envenomation effects, Russell's viper bites induce some rare complications such as priapism, sialolithiasis and splenic rupture. Here, we report a case of Wunderlich syndrome that developed in a 22-year-old male following a Russell's viper bite. The patient displayed severe coagulopathies, abdominal tenderness, and hypotension. Notably, a peri-nephric haematoma was identified through ultrasound and computerised tomographic imaging. The haemorrhage was successfully treated using angioembolisation, and the patient recovered without any difficulties. Although a clinical condition such as this is rare, it is important to create awareness among treating clinicians about its occurrence, diagnosis and clinical management.

Profiling the Murine Acute Phase and Inflammatory Responses to African Snake Venom: An Approach to Inform Acute Snakebite Pathology

Snake envenoming causes rapid systemic and local effects that often result in fatal or long-term disability outcomes. It seems likely that acute phase and inflammatory responses contribute to these haemorrhagic, coagulopathic, neurotoxic, nephrotoxic and local tissue destructive pathologies. However, the contributory role of acute phase/inflammatory responses to envenoming is under-researched and poorly understood—particularly for envenoming by sub-Saharan African venomous snakes. To provide data to help guide future studies of human patients, and to explore the rationale for adjunct anti-inflammatory medication, here we used an in vivo murine model to systematically assess acute phase and inflammatory responses of mice to ten African snake venoms. In addition to investigating snake species-specific effects of venom on the cardiovascular system and other key organs and tissues, we examined the response to intravascular envenoming by acute phase reactants, including serum amyloid A, P-selectin and haptoglobin, and several cytokines. Venoms of the spitting (Naja nigricollis) and forest (N. melanoleuca) cobras resulted in higher acute phase and inflammatory responses than venoms from the other cobras, mambas and vipers tested. Naja nigricollis venom also stimulated a 100-fold increase in systemic interleukin 6. Thin blood films from venom-treated mice revealed species-specific changes in red blood cell morphology, indicative of membrane abnormalities and functional damage, lymphopenia and neutrophil leukocytosis. Our ex vivo assays with healthy human blood treated with these venoms identified that N. nigricollis venom induced marked levels of haemolysis and platelet aggregation. We conclude that African snake venoms stimulate very diverse responses in this mouse model of acute systemic envenoming, and that venoms of the African cobras N. nigricollis and N. melanoleuca, in particular, cause marked inflammatory and non-specific acute phase responses. We also report that several African snake venoms cause haemolytic changes. These findings emphasise the importance of understanding acute responses to envenoming, and that further research in this area may facilitate new diagnostic and treatment approaches, which in turn may lead to better clinical outcomes for snakebite patients.

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.

Neutrophil Gelatinase-Associated Lipocalin Acts as a Robust Early Diagnostic Marker for Renal Replacement Therapy in Patients with Russell's Viper Bite-Induced Acute Kidney Injuries

Snakebite-induced acute kidney injury (AKI) is frequently observed in patients following bites from vipers such as Russell's viper (Daboia russelii) in India. Currently, the levels of serum creatinine are mainly used as a marker to determine the necessity for renal replacement therapy (RRT) (haemodialysis) in severe cases of AKI. However, it takes up to 48 h to ascertain a distinct change in creatinine levels compared to its baseline level upon admission. The time lost between admission and the 48 h timepoint significantly affects the clinical management of snakebite victims. Moreover, early diagnosis of AKI and decision on the necessity for RRT in snakebite victims is critical in saving lives, reducing long-term complications, and minimising treatment costs arising from expensive haemodialysis. Neutrophil gelatinase-associated lipocalin (NGAL) has been recently studied as a robust early marker for AKI in non-snakebite patients. However, its suitability for clinical use in snakebite victims has not been rigorously established. Here, we demonstrate the clinical significance of plasma NGAL as a robust marker for RRT following AKI using a large cohort (309) of Russell's viper victims without any pre-existing health conditions. NGAL levels upon admission are positively correlated with creatinine levels at 48 h in different stages of AKI. Overall, NGAL acts as a robust early marker to ascertain the need for RRT following Russell's viper bites. The quantification of NGAL can be recommended as a routine test in hospitals that treat snakebites to decide on RRT at early time points instead of waiting for 48 h to confirm the increase in creatinine levels. The diagnostic use of NGAL in Russell's viper victims with pre-existing comorbidities and for other vipers should be evaluated in future studies.

Splenic Rupture and Massive Hemoperitoneum Due to Coagulopathy after Atheris Viper Snakebite

Coagulopathy with defibrination is one of symptoms accompanying snakebite envenoming, where life-threatening complications such as massive bleeding and organ hematomas formation can occur. Here, we report a case of hemocoagulation failure due to bite by African Great Lakes bush viper Atheris nitschei with impossibility of specific treatment for absence of antivenom and its life-threatening complication: very rare and unexpected atraumatic splenic rupture with massive hemoperitoneum and necessity of urgent splenectomy.

Scrotal necrosis after cobra (Naja annulifera) envenomation

A 47-year-old man received a snouted cobra (Naja annulifera) snake bite to his genitals while on holiday in South Africa. His penis and scrotum were noted to be swollen, deep purple in color, and painful on hospital admission. Scrotal necrosis was diagnosed, and he received multiple doses of a non-specific snake venom antiserum and broad-spectrum antibiotics. Although no neurological sequelae developed, he did require hemodialysis due to acute kidney injury. After stabilizing, he was repatriated to the Netherlands for further treatment and has since made a full recovery.

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Ours is the first case describing Naja annulifera envenomation of the genitals.

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Treatment usually requires antidote and broad-spectrum antibiotic administration.

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Some cases also need surgical debridement or more intensive acute care.

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Genital function and esthetics have a good chance of recovery with early treatment.

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Esthetic surgery should only be performed after the acute phase.

Erythrocyte haemotoxicity profiling of snake venom toxins after nanofractionation

Snakebite is classified as a priority Neglected Tropical Disease by the World Health Organization. Understanding the pathology of individual snake venom toxins is of great importance when developing more effective snakebite therapies. Snake venoms may induce a range of pathologies, including haemolytic activity. Although snake venom-induced erythrocyte lysis is not the primary cause of mortality, haemolytic activity can greatly debilitate victims and contributes to systemic haemotoxicity. Current assays designed for studying haemolytic activity are not suitable for rapid screening of large numbers of toxic compounds. Consequently, in this study, a high-throughput haemolytic assay was developed that allows profiling of erythrocyte lysis, and was validated using venom from a number of medically important snake species (Calloselasma rhodostoma, Daboia russelii, Naja mossambica, Naja nigricollis and Naja pallida). The assay was developed in a format enabling direct integration into nanofractionation analytics, which involves liquid chromatographic separation of venom followed by high-resolution fractionation and subsequent bioassaying (and optional proteomics analysis), and parallel mass spectrometric detection. Analysis of the five snake venoms via this nanofractionation approach involving haemolytic assaying provided venom-cytotoxicity profiles and enabled identification of the toxins responsible for haemolytic activity. Our results show that the elapid snake venoms (Naja spp.) contained both direct and indirect lytic toxins, while the viperid venoms (C. rhodostoma and D. russelii) only showed indirect lytic activities, which required the addition of phospholipids to exert cytotoxicity on erythrocytes. The haemolytic venom toxins identified were mainly phospholipase A2s and cytotoxic three finger toxins. Finally, the applicability of this new analytical method was demonstrated using a conventional snakebite antivenom treatment and a small-molecule drug candidate to assess neutralisation of venom cytotoxins.

Evaluation of Allergic Reactions Following Intravenous Infusion of Polyvalent Antivenom in Snakebite Patients

BACKGROUND

Antivenom is a gold-standard treatment for snakebite envenoming. However, adverse reactions to snake antivenom are common in many parts.

OBJECTIVE

The aim of this study was to evaluate the allergic reactions following intravenous administration of antivenom sera.

METHODS

This was retrospective study, conducted snakebites patients referred to the Rahimi Hospital in Khorramabad. The files of these patients were accessed for demographic data, snakebite-related data, treatment provided, clinical presentation and allergic reaction status as a result of antivenom treatment.

RESULTS

141 cases were investigated including 73.8% male and 26.2% female patients. The mean age of the patients was 38.1±17.1years. Age group 30-39 years accounted for highest number of snakebite cases (24.1%). A majority of victims (89.4%) were from the rural areas. Most of the patients (51.8%) were bitten in the spring and highest number of snakebite were reported in May (39.1%). The most common site of snakebite was lower extremities (50.4%) and upper extremities (44.7%). Among clinical feature of snakebite, pain was the most prevalent in 135 cases (95.7%) followed by swelling (83.7%). The mean antivenom vials used were 6.5±3.7 vials. Allergic reactions occurred in 6 patients (4.26%); reactions were mild in 5 patients and sever in 1patient. The commonest presentation was maculopapular rash (1.4%) and the least common were headache (0.71%), nausea (0.71%), fever (0.71) and hypotension (0.71%).

CONCLUSION

Snakebite is one of the significantlife-threatening environmental events.Immediate antivenom treatment can reduce mortality however, patients should be carefully monitored for adverse allergic reactions.

Etiological Spectrum and Histopathological Diagnosis of Rhabdomyolysis Associated Myoglobin Cast Nephropathy in South India

Background and Aims:

Rhabdomyolysis occurs due to injury to skeletal muscle fibers and the release of muscle constituents into the circulation. Myoglobin cast nephropathy leading to acute kidney injury is one of the most severe complications of rhabdomyolysis. This is a retrospective study which aims to analyse the clinicopathological features of myoglobin cast nephropathy.

Methods:

A total of 57 cases of myoglobin cast nephropathy were identified after performing immunohistochemical staining for myoglobin on all renal biopsies with pigment casts. The clinical, laboratory data, histopathological findings and clinical outcome of these cases were evaluated.

Results:

The mean patient age was 34.47 years (range 17-77) and the male to female ratio was 6.1:1. All patients presented with acute kidney injury with mean serum creatinine of 8.4 mg/dl (range: 1.7 to 20.8 mg/dl). Rhabdomyolysis was clinically suspected only in 31 patients. Along with myoglobin casts, acute tubular injury was present in all the biopsies. The most frequent conditions associated with myoglobin cast nephropathy in our study were snake envenomation and unaccustomed physical activities. A few activities that caused rhabdomyolysis in our patients were unique to India.

Conclusion:

Clinicians should be aware of the wide spectrum of causes for rhabdomyolysis. The classical clinical and laboratory findings of rhabdomyolysis may not be present in many of the patients. The pathologist must have a high index of suspicion, and immunohistochemical stain should be used to confirm the diagnosis.

Community-Acquired AKI in Asia: An Update

Community-acquired acute kidney injury (CA-AKI) is the dominant form of AKI encountered in developing countries in Asia. Economic disparities, variations in access to health care services, geographic conditions, environmental risk factors, and sociocultural circumstances shape the causes and outcomes of CA-AKI. Infections, drugs, plant and chemical toxins, envenomations, and obstetric complications are common causes of CA-AKI. Previously healthy young individuals who often work outdoors in fields or farms are exposed to a wide variety of work-related or environmental risk factors for CA-AKI. Improving disease definitions, better data, and evolving host-pathogen interactions have changed disease descriptions and presentations over the past 20 years. Among infections, although the incidence of malaria has decreased, the number of cases with dengue and scrub typhus have increased sharply. The recognition of AKI in relation to Plasmodium knowlesi, Plasmodium vivax, scrub typhus, and leptospirosis in areas not traditionally considered at risk, association of infections with the future development of chronic kidney disease, and the role of complement dysregulation in infection-associated AKI are important new findings. Snake-bite-related toxic envenomation continues to be an important cause of AKI in some counties and is a neglected public health problem. On the other hand, significant decreases in the incidence of AKI related to acute diarrheal illness or obstetric causes are signs of hope. Coordinated efforts between administrative stakeholders, society, and health care delivery services at all levels have the potential to propel research and improve outcomes in CA-AKI.

Chronic kidney failure following lancehead bite envenoming: a clinical report from the Amazon region

Background:

Snakebite envenoming can be a life-threatening condition, for which emergency care is essential. The Bothrops (lancehead) genus is responsible for most snakebite-related deaths and permanent loss of function in human victims in Latin America. Bothrops spp. venom is a complex mixture of different proteins that are known to cause local necrosis, coagulopathy, and acute kidney injury. However, the long-term effects of these viper envenomings have remained largely understudied.

Case presentation:

Here, we present a case report of a 46-years old female patient from Las Claritas, Venezuela, who was envenomed by a snake from the Bothrops genus. The patient was followed for a 10-year period, during which she presented oliguric renal failure, culminating in kidney failure 60 months after the envenoming.

Conclusion:

In Latin America, especially in Brazil, where there is a high prevalence of Bothrops envenoming, it may be relevant to establish long-term outpatient programs. This would reduce late adverse events, such as chronic kidney disease, and optimize public financial resources by avoiding hemodialysis and consequently kidney transplantation.

Acute kidney failure following severe viper envenomation: clinical, biological and ultrasonographic aspects

Background:

Acute kidney injury (AKI) is a frequent complication of snakebite envenomation, which is still little known in sub-Saharan Africa. This study aims to describe the clinical, biological and ultrasonographic aspects of AKI following severe snakebite envenomation managed in the intensive care unit.

Method:

A prospective observational survey was performed in Benin over a period of 18 months. All patients suffering severe snakebite envenomation (SBE) were included. The diagnosis of AKI was made using the KDIGO criteria. Kidney ultrasound exam was performed in all patients to assess internal bleeding and morphological and structural abnormalities of the kidneys.

Results:

Fifty-one cases of severe SBE were included. All patients presented inflammatory syndrome and showed abnormal WBCT whereas bleeding was found in 46 of them (90%). The median time to hospital presentation was three days. The majority of patients were male (M/F sex ratio = 1.55) and the median age was 26. Sixteen patients (31%) showed AKI according to the KDIGO criteria. Severe AKI (KDIGO stage 2 and 3) was observed in three patients, including one stage 2 and two stage 3. Kidney ultrasound revealed three cases of kidney capsular hematoma (6%), two cases of kidney hypertrophy (3%), three cases of kidney injury (4%), two stage 1 KDIGO and one stage 2 KDIGO. Only one patient benefited from hemodialysis. All patients showing AKI recovered without sequels. The median duration of hospital stays was four days. Seven patients died (14%) including four among the 16 AKI patients. Antivenom has been administered to 41 patients (80%). The comparison between patients without and with AKI did not show any significant difference except gender (p = 10^-2).

Conclusion:

AKI is a common complication of severe snakebite envenomation. Resulting from inflammatory and hemorrhagic disorders, AKI may prove to be a short-term life-threatening factor.

Snakebite Envenoming a Challenging Diagnosis for the Forensic Pathologist: A Systematic Review

Snakebite envenoming (SBE) is a public health issue in developing countries. The estimated annual global incidence of snakebites is about 5.4 million snakebites per year, resulting from 1.8 to 2.7 million cases of SBE and from 81,000 to 138,000 deaths with 400,000 survivors suffering permanent physical and psychological disabilities. There are more than 3000 species of snakes around the world: 600 are venomous and over 200 are considered to be medically important because of their clinical effects. The severity of SBE depends on several factors among which bite localization, snake's size, condition of glands and teeth, bite angle and bite duration, the microflora of the snake's mouth and victim's skin, age of the victim, weight, health status, and victim's activity after a bite. Snake venoms are mixtures of protein families, and each of these families contains many different toxins or toxin isoforms. Based on their effects, snake venoms can be classified as hemotoxic, neurotoxic, or cytotoxic and they can all act together involving multiple tissues and organs. When the bite is fatal, the mechanism of death is primarily related to the paralysis of respiratory muscles, which causes asphyxia and hypoxic-ischemic encephalopathy, but also anaphylactic shock, hemorrhagic shock, cardiomyopathy, acute tubular necrosis (ATN). The purpose of this literature review is to evaluate epidemiological and post-mortem examination findings in fatal SBEs in order to better understand the pathophysiological mechanisms, thus helping pathologists in defining the correct diagnosis.

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 Urgent Need to Develop Novel Strategies for the Diagnosis and Treatment of Snakebites

Snakebite envenoming (SBE) is a priority neglected tropical disease, which kills in excess of 100,000 people per year. Additionally, many millions of survivors also suffer through disabilities and long-term health consequences. The only treatment for SBE, antivenom, has a number of major associated problems, not least, adverse reactions and limited availability. This emphasises the necessity for urgent improvements to the management of this disease. Administration of antivenom is too frequently based on symptomatology, which results in wasting crucial time. The majority of SBE-affected regions rely on broad-spectrum polyvalent antivenoms that have a low content of case-specific efficacious immunoglobulins. Research into small molecular therapeutics such as varespladib/methyl-varespladib (PLA2 inhibitors) and batimastat/marimastat (metalloprotease inhibitors) suggest that such adjunctive treatments could be hugely beneficial to victims. Progress into toxin-specific monoclonal antibodies as well as alternative binding scaffolds such as aptamers hold much promise for future treatment strategies. SBE is not implicit during snakebite, due to venom metering. Thus, the delay between bite and symptom presentation is critical and when symptoms appear it may often already be too late to effectively treat SBE. The development of reliable diagnostical tools could therefore initiate a paradigm shift in the treatment of SBE. While the complete eradication of SBE is an impossibility, mitigation is in the pipeline, with new treatments and diagnostics rapidly emerging. Here we critically review the urgent necessity for the development of diagnostic tools and improved therapeutics to mitigate the deaths and disabilities caused by SBE.

Prognosis and long-term outcomes of acute kidney injury due to snake envenomation

Background

Snakebite is a common occupational hazard in tropical countries. To date, the literature on snakebite-related acute kidney injury (AKI) has been limited by retrospective study designs, lack of uniformity in case definitions of AKI and limited follow-up. This study aims to identify the in-hospital outcomes and long-term changes in kidney function that follow haemotoxic envenomation.

Methods

All adult patients admitted with AKI following haemotoxic envenomation from January 2016 to June 2017 were recruited and followed up until July 2018. Predictors of in-hospital mortality was assessed. Long-term follow-up data on kidney function were collected from survivors.

Results

In total, 184 patients with haemotoxic envenomation and AKI were recruited. The mean age of the subjects was 42.2 years [95% confidence interval (CI) 40.3–44.7]. The majority were male (71.2%). The mortality of patients with haemotoxic envenomation was 21.5%. The mortality was considerably higher in patients with Kidney Disease: Improving Global Outcomes (KDIGO) Stage 3 AKI [relative risk (RR) 4.45 (95% CI 1.14–17.42)] and those who met KDIGO urine output criteria [RR 20.45 (95% CI 2.84–147.23)]. A Cox regression model identified mechanical ventilation [odds ratio (OR) 5.59 (95% CI 2.90–10.81)], hypotension [OR 2.48 (95% CI 1.31–4.72)] and capillary leak syndrome [OR 2.02 (95% CI 1.05–3.88)] as independent predictors of mortality. Long-term follow-up data were available for 73 patients. A total of 21 patients (28.7%) developed adverse renal outcomes (glomerular filtration rate <60 mL/min/1.73 m², urine albumin excretion >30 mg/g and new-onset hypertension or prehypertension).

Conclusions

AKI resulting from snake envenomation is associated with considerable risk of mortality. The greater the AKI stage the greater the likelihood of mortality. One-third of patients with AKI developed long-term complications like chronic kidney disease, prehypertension and hypertension over the follow-up period.

Low accuracy of microscopic hematuria in detecting coagulopathy from Bothrops pit viper bites, Brazilian Amazon

Introduction: The common lancehead snakes (Bothrops atrox) are responsible for up to 90% of snakebites in the Amazon, especially in remote areas. The prevalence of microhematuria is similar to that of coagulopathy in B. atrox envenomation in the Amazon. Thus, this study aimed to assess the reliability of microhematuria as an inexpensive and simple alternative to detect snake-induced consumption coagulopathy. Methods: We analyzed samples from patients with confirmed B. atrox envenomation in terms of plasma fibrinogen and microhematuria (>3 red blood cells per high power field) in order to access the reliability of microhematuria to detect snakebite-induced coagulopathy, within 12 hours from admission. Results: A total of 186 patients were recruited. From the total, 85.5% of patients had hypofibrinogenemia and only about 50% (n = 94) had a microscopic examination of urine within 12 hours where microhematuria was present in 39 (41.5%). Diagnostic performance showed 38.6% sensitivity and 36.4% specificity (cutpoint 200 mg/dL). No clear association was seen between microhematuria and hypofibrinogenemia (r: -0.10; p: .34). Conclusion: In this study, microhematuria presented poor diagnostic performance to detect coagulopathy. Further studies are necessary to screen inexpensive and simple alternative diagnostic tools.

Short-term Changes in Urine Beta 2 Microglobulin Following Recovery of Acute Kidney Injury Resulting From Snake Envenomation

Introduction

Urine β2 microglobulin (β2m) is a validated marker to diagnose sepsis and toxin-related acute kidney injury (AKI). In the current study, we used urine β2m as a potential marker to identify persistent tubular dysfunction following a clinical recovery from snake venom–related AKI.

Methods

A total of 42 patients who developed AKI following hemotoxic envenomation were followed up for a period of 6 months. Urine albumin excretion, estimated glomerular filtration rate (eGFR), and urine β2m levels were measured at 2 weeks, 3 months, and 6 months following discharge.

Results

At the end of 6 months of follow-up, 6 patients (14.3 %) progressed to chronic kidney disease (CKD) (eGFR < 60 ml and/or urine albumin excretion > 30 mg/d). The urine β2m levels were 1590 μg/l (interquartile range [IQR] 425–5260), 610 μg/l (IQR 210–1850), 850 μg/l (IQR 270–2780) at 2 weeks, 3 months, and 6 months, respectively (P = 0.020). The levels of urine β2m in the study population at the end of 6 months remained significantly higher compared with the levels in healthy control population (850 μg/l [IQR 270–2780] vs. 210 μg/l [IQR 150–480]; P = 0.001). The proportion of patients with urine β2m levels exceeding the 95th percentile of control population (>644 µg/l) during the 3 follow-up visits were 70.7% (n = 29), 48.8 % (n = 20), and 51.2% (n = 21). Similar trends were noticed in a sensitivity analysis, after excluding patients with CKD.

Conclusions

Urine β2m levels remain persistently elevated in approximately half of the individuals who recover from AKI due to snake envenomation.

An unusual case of gross myoglobinuria in a child following Russell's viper (Daboia russelii) envenomation

Overt myoglobinuria associated with myotoxicity is a classic feature of sea snake envenomation. Russell's viper bites usually result in coagulopathy, neurotoxicity and nephrotoxicity but rarely myotoxicity has been reported, especially in the Sri Lankan variety (Daboia russelii). All those studies have demonstrated mild degree myotoxicity with microscopic level myoglobinuria. We report what is probably the first case of gross myoglobinuria in a child following a Russell's viper bite with biochemical evidence of significant myotoxicity well beyond the levels that have been previously reported.

Ameliorating effect of Alstonia scholaris L. bark extract on histopathological changes following viper envenomation in animal models

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In the present paper, the histopathological changes of liver and kidney tissues associated with Vipera russelli envenomation and systemic venom neutralization potential of aqueous Alstonia scholaris Linn bark extract in animal models has been discussed.

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Histological alterations observed in liver sections of venom treated groups were mainly pyknosis, karyorrhexis, cytoplasmic vacuolation, necrosis, fatty changes and hepatocytes atrophy.

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Histological changes in venom treated kidney tissues were cell damage, peritubular congestion, degenerating changes in the proximal tubules in the form of cytoplasmic vacuolations, partially destroyed bowman’s capillaries with dilated Bowman’s space after staining with haematoxylin and eosin.

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Both Antivenom and Alstonia scholaris Linn extract could significantly reduce the venom induced histological as well as biochemical changes (serum AST,ALT and creatinine) in the affected tissues.

Objectives

The primary symptoms associated with snake envenomation are both systemic and local. The local symptoms are characterized by pain, swelling, haemorrhage and myonecrosis at the site of bite. The present study investigates the ameliorating effect of the aqueous bark extract of Alstonia scholaris bark on viper venom induced histopathological and biochemical changes in liver and kidney of swiss albino mice models.

Methods & materials

Swiss albino mice (20 ± 2)g were treated with sublethal doses(0.5 μg and 1 μg) of Vipera russelli venom(VRV) intraperitonially The following groups were assigned in the study-Group I(saline control); Group II & III(Venom treated-0.5 μg ie ¼ LD50 and 1 μg ie 1/2 LD50) and Group IV &V(Venom-0.5 μg and 1 μg respectively incubated with Aqueous Alstonia scholaris (AAS) extract; 200 mg/kg bw) and Group VI (Antivenom serum (AVS) (2 mg/ml) followed by 1 μg Vipera russelli venom (VRV). The animals were sacrificed and their organs were immersed in Bouin's fixative for 24 h and stained with haematoxylin/eosin and observed under the microscope. The serum samples were collected from the animals and tested for serum Alanine transaminase (ALT) and Aspartate transaminases (AST) following the method of Reitman & Frankel(1957) and serum creatinine.

Results

The histological alterations observed in Group II and III liver sections were mainly pyknosis, karyorrhexis, cytoplasmic vacuolation, necrosis, fatty changes and hepatocytes atrophy. Sinusoidal dilatation, amyloidosis, portal vein thrombosis which was significantly reduced by AAS extract in Groups IV and V. A venom dose of 1 μg induced tubular cell acidophilia indicating cell damage, peritubular congestion, degenerating changes in the proximal tubules in the form of cytoplasmic vacuolations, partially destroyed bowman’s capillaries with dilated Bowman’s space in Group III that was significantly reduced by Aqueous Alstonia scholaris (AAS) (200 mg/kg bw) extract in Groups IV and Group V.AVS gave significant protection against venom induced action in Group VI.

Conclusion

The present paper thus highlights the histopathological changes associated with Vipera russelli venom and systemic venom neutralization potential of Aqueous Alstonia scholaris (AAS) in animal models.