Bilateral renal cortical necrosis with end-stage renal failure following envenoming by Proatheris superciliaris: a case report

Sudden death after a bite by a lowland swamp viper (Proatheris superciliaris) in Malawi: Dying of fright?

Proatheris superciliaris, the lowland swamp viper, has a limited distribution along lakeshores and rivers in Malawi, Southern Tanzania, and central Mozambique. Its venom is known to be procoagulant. Only five P. superciliaris bites have been reported, all inflicted by captive snakes, and none was fatal. Here we present a case of sudden death following a bite by Proatheris superciliaris in rural Malawi that cannot be attributed to envenoming. A healthy 32-year-old woman was planting rice in a flooded rice paddy field when she suddenly told her sister in a quiet voice that she had been bitten by a snake. She then collapsed face-upwards into the ankle-deep water. She remained motionless while her sister and uncle carried her out of the rice paddy onto dry land a few meters away. The victim did not regain consciousness. Her uncle heard one exhalation but no further breathing. The snake responsible was killed by a friend. Although the venom of this species can cause life-threatening coagulopathy, this woman's death occurred too rapidly to be attributable to envenoming. Only two explanations seem plausible: anaphylaxis, or vasovagal shock triggered by fear. In the present case, the victim died within minutes of the bite, closely observed by her anxious relatives, but showed no features of anaphylaxis. In Malawi, as in much of sub-Saharan Africa, many people are reportedly terrified of snakes, believing that bites by almost any species can cause rapid death. In this case, death occurred less than 2 min after a bite from Proatheris superciliaris. We believe that the cause of death was most likely a severe vasovagal attack, in response to the fear and pain of the snakebite that triggered vasodilatation, bradycardia, and hypotension leading to cardiac arrest.

Bites by Non-Native Reptiles in France: Species, Circumstances and Outcome

We aimed to make an exhaustive assessment of circumstances of bites by exotic reptiles bred in France. A retrospective observational study was conducted in all the reported cases from 2000 to 2020 in French poison control centers (PCCs). Two hundred and eighteen cases of bites were recorded. The sex ratio (M/F) of the patients was 1.79 and the mean age of the patients was 29.0 ± 15.8 years. Twenty-two cases (10.1%) occurred during the deep night. One hundred and eighty-six bites (85.7%) occurred in a private context; however, there were more cases of high severity when it occurred in a professional setting (60.0% vs. 11.2%, p < 0.01). The feeding/nursing activity accounted for 54.7% cases. Forty-three species of snake were identified; 28 were considered venomous. There were no deaths among the patients in the study. Most of the cases (85.8%) were of mild severity. All of the patients bitten by a venomous reptile were hospitalized: 10 patients received an antivenom; and 2 required surgery. Bites occurred at home and by a small number of popular non-venomous reptile species (pythons and boas, colubrids). These occurred mainly when handling the animals. The rare envenomations were mainly by Asian and American crotalids, followed by elapids. One-third of them were treated with antivenom when available.

Review of the Mechanisms of Snake Venom Induced Pain: It's All about Location, Location, Location

Pain—acute, chronic and debilitating—is the most feared neurotoxicity resulting from a survivable venomous snake bite. The purpose of this review is to present in a novel paradigm what we know about the molecular mechanisms responsible for pain after envenomation. Progressing from known pain modulating peptides and enzymes, to tissue level interactions with venom resulting in pain, to organ system level pain syndromes, to geographical level distribution of pain syndromes, the present work demonstrates that understanding the mechanisms responsible for pain is dependent on “location, location, location”. It is our hope that this work can serve to inspire the molecular and epidemiologic investigations needed to better understand the neurotoxic mechanisms responsible for these snake venom mediated diverse pain syndromes and ultimately lead to agent specific treatments beyond anti-venom alone.

Effect of Traditional Chinese Medicine on Long-Term Outcomes of Snakebite in Taiwan

Herein, we review the characteristics of the six predominant venomous snakes in Taiwan and the effects of traditional Chinese medicine on the long-term outcomes of snakebite venom. We electronically searched databases, including PubMed, ClinicalKey, China National Knowledge Infrastructure, National Digital Library of Theses and Dissertations in Taiwan, and Airiti Library, from their inception to November 2019 by using the following Medical Subject Headings' keywords: snakebite, long-term, chronic, Chinese medicine, CAM, herb, and Taiwan. The most common long-term effects of snakebite envenomation include "migraine-like syndrome", brain injuries caused by hypoxia or intracranial hemorrhage, and chronic kidney disease. In addition, hypopituitarism is also worth mentioning. Traditional Chinese medicine can potentially be used in a complementary or alternative treatment for these effects, but additional studies are needed.

Venomous Landmines: Clinical Implications of Extreme Coagulotoxic Diversification and Differential Neutralization by Antivenom of Venoms within the Viperid Snake Genus Bitis

The genus Bitis comprises 17 snake species that inhabit Africa and the Arabian Peninsula. They are responsible for a significant proportion of snakebites in the region. The venoms of the two independent lineages of giant Bitis (B. arietans and again in the common ancestor of the clade consisting of B. gabonica, B. nasicornis, B. parviocula and B. rhinoceros) induce an array of debilitating effects including anticoagulation, hemorrhagic shock and cytotoxicity, whilst the dwarf species B. atropos is known to have strong neurotoxic effects. However, the venom effects of the other species within the genus have not been explored in detail. A series of coagulation assays were implemented to assess the coagulotoxic venom effects of fourteen species within the genus. This study identified procoagulant venom as the ancestral condition, retained only by the basal dwarf species B. worthingtoni, suggesting anticoagulant venom is a derived trait within the Bitis genus and has been secondarily amplified on at least four occasions. A wide range of anticoagulant mechanisms were identified, such as coagulant and destructive activities upon fibrinogen in both giant and dwarf Bitis and the action of inhibiting the prothrombinase complex, which is present in a clade of dwarf Bitis. Antivenom studies revealed that while the procoagulant effects of B. worthingtoni were poorly neutralized, and thus a cause for concern, the differential mechanisms of anticoagulation in other species were all well neutralized. Thus, this study concludes there is a wide range of coagulotoxic mechanisms which have evolved within the Bitis genus and that clinical management strategies are limited for the procoagulant effects of B. worthingtoni, but that anticoagulant effects of other species are readily treated by the South African polyvalent antivenom. These results therefore have direct, real-work implications for the treatment of envenomed patients.

Snakebite Induced Thrombotic Microangiopathy Leading to Renal Cortical Necrosis

Renal complications from snakebite result in high mortality and morbidity. Acute kidney injury (AKI) occurs in 5–30% of cases. Renal manifestation could include acute tubular necrosis, cortical necrosis, interstitial nephritis, glomerulonephritis, and vasculitis. We present a case of thrombotic microangiopathy (TMA) resulting in renal cortical necrosis. Renal biopsy showed fibrin thrombi in glomeruli and arterioles with cortical necrosis. Our patient progressed to end-stage renal disease.

Disseminated intravascular coagulation caused by moojenactivase, a procoagulant snake venom metalloprotease

Snake venom toxins that activate coagulation factors are key players in the process of venom-induced coagulopathy, and account for severe clinical manifestations. The present study applies a variety of biochemical, hematological, and histopathological approaches to broadly investigate the intravascular and systemic effects of moojenactivase (MooA), the first described PIIId subclass metalloprotease isolated from Bothrops sp. venom that activates coagulation factors. MooA induced consumption coagulopathy with high toxic potency, characterized by prolongation of prothrombin and activated partial thromboplastin time, consumption of fibrinogen and the plasma coagulation factors X and II, and thrombocytopenia. MooA promoted leukocytosis and expression of the proinflammatory cytokines interleukin-6 and tumor necrosis factor-α, accompanied by tissue factor-dependent procoagulant activity in peripheral blood mononuclear cells. This metalloprotease also caused intravascular hemolysis, elevated plasma levels of creatine kinase-MB, aspartate transaminase, and urea/creatinine, and induced morphopathological alterations in erythrocytes, heart, kidney, and lungs associated with thrombosis and hemorrhage. Diagnosis of MooA-induced disseminated intravascular coagulation represents an important approach to better understand the pathophysiology of Bothrops envenomation and develop novel therapeutic strategies targeting hemostatic disturbances.