Severe Envenomation Research Articles

Myocardial Ischemia after Severe Scorpion Envenomation: A Narrative Review.

Myocardial ischemia after severe scorpion envenomation is rarely reported. The aim of this review was to elaborate on a review of myocardial ischemia after severe scorpion envenomation and to detail the mechanism of this myocardial hypoperfusion. We used the PubMed database and entered the following keywords in MeSH research: scorpion envenomation, myocardial ischemia, myocardial perfusion scintigraphy, echocardiography, and troponins. The literature analysis confirmed that severe scorpion envenomation can be complicated by temporary myocardial ischemia, based on electrocardiographic, histopathologic, echocardiographic, myocardial perfusion scintigraphy, and biological studies. The correlation between clinical manifestations, laboratory and electrocardiographic evidence of myocardial damage, echocardiographic studies, perfusion scintigraphy abnormalities, and histopathologic findings are suggestive of lesions of cardiac fibers secondary to myocardial ischemia. Myocardial hypoperfusion may be due to multiple factors. First, catecholamine storms can induce microvascular constriction. On the other hand, the release of catecholamines through a complex neurohormonal interaction with other neuropeptides and cytokine release can produce/induce major coronary microvascular constriction and/or microvascular injury, leading to microvascular acute coronary syndrome with Takotsubo cardiomyopathy. The management of severe scorpion envenomation with severe myocardial failure and pulmonary edema is based on oxygen with invasive or noninvasive ventilator support. Dobutamine improves cardiac function after scorpion envenomation. Antiplatelet therapy is not recommended. In conclusion, severe scorpion envenomation can be complicated by temporary myocardial ischemia, which can be due to multiple factors.

Oral varespladib for the treatment of snakebite envenoming in India and the USA (BRAVO): a phase II randomised clinical trial

IntroductionSnakebite envenoming (SBE) results in over 500 000 deaths or disabling injuries annually. Varespladib methyl, an oral inhibitor of secretory phospholipase A2, is a nearly ubiquitous component of snake venoms....

Ophthalmic effects of Bitis atropos (Berg Adder) envenomation

Objective: Bitis atropos, commonly known as the Berg Adder, is a venomous viperid found in Southern Africa. Envenomation is rare, with reported cases primarily exhibiting cytotoxic, neurotoxic, and myotoxic effects, including severe systemic manifestations and ophthalmologic complications such as ptosis, mydriasis, and loss of accommodation. However, the underlying pathophysiology of these sequelae remains poorly understood. Case: We present the case of a 26-year-old male who suffered severe envenomation by a Berg Adder in the Limpopo Province, South Africa. Within minutes of the bite, the patient experienced hypoesthesia, progressive dyspnea, and loss of consciousness, followed by prolonged intensive care management. Ophthalmic examination revealed bilateral dilated pupils, right ptosis, and impaired accommodation, alongside generalized muscle weakness, anosmia, ageusia, and dysphagia. Despite the absence of antivenom, the patient’s condition showed gradual improvement over a 127-day follow-up period. Notably, the pupils exhibited denervation supersensitivity, similar to Adie’s tonic pupil, and responded well to low-dose pilocarpine. Conclusion: The clinical features observed, particularly the ophthalmoplegic triad, can be attributed to the effects of phospholipase A2 proteins in the venom, which disrupt cholinergic transmission at muscarinic receptors. This case underscores the complexity of Berg Adder envenomation and highlights the variability in recovery timelines for different neuro-ophthalmic effects. This case provides valuable insights into the pathophysiology and management of severe Berg Adder envenomation, emphasizing the role of targeted therapeutic interventions such as pilocarpine in mitigating long-term sequelae.

Snakebites by venomous snakes in Brazilian serpentaria and zoos over a 10-year period (2012–2021)

Despite the wide range of institutions that maintain venomous snakes in captivity in Brazil there are no comprehensive data on the occurrence of snakebites and envenomations in these places. We examined the range of native and exotic species of venomous snakes kept by Brazilian zoos and serpentaria (scientific and commercial) and assessed the frequency of snakebites in workers handling these snakes during a 10-year period (2012–2021). Twenty-two (73.3%) of 30 institutions returned a standard questionnaire, including 15 serpentaria and 7 zoos that together kept 10,607 venomous snakes in 2022/2023. Commercial and scientific serpentaria had many more snakes (n = 10,550, consisting of 10,499 native specimens and 51 exotic specimens) than zoos (n = 57 native specimens), with two genera accounting for the majority of native species (Bothrops spp. = 84.5% and Crotalus durissus ssp. = 13.5%). Thirty-seven snakebites were reported and involved primarily the hands (33), seven of which occurred during venom extraction and 30 in other circumstances, most of them while handling/manipulating the cages or snake boxes (10) and restraining (9) or feeding (5) the snake. In addition, there were two cases of venom accidently sprayed on the face, including the eyes. Most bites were caused by Bothrops spp. (31), followed by C. durissus ssp. (4), Lachesis muta (1) and Micrurus corallinus (1). Thirty-three bites (89.2%) were treated with antivenom, with four bites to the fingers by Bothrops spp. resulting in local functional sequelae. There were 366,918 venom extractions with a ratio of 1.9 bites/100,000 extractions; no bites were recorded in the six institutions that sedated the snakes prior to venom extraction, which accounted for 22.7% of all extractions. These findings show that although snakebites are rare in Brazilian zoos and serpentaria, severe envenomation may occur. The occurrence of snakebites could be reduced by measures such as sedation of the snakes before venom extraction.

Evaluation of the International Society on Thrombosis and Haemostasis definition of major bleeding in Arizona rattlesnake bites

Introduction In 2023, a group of experts proposed that a definition of major bleeding in pharmaceutically anticoagulated patients be used in all snakebite trials. This includes bleeding that results in death, is life-threatening, causes chronic sequelae, or consumes major healthcare resources, including bleeding into a major area or hemoglobin concentration decrease ≥20 g/L. We hypothesized that a decline in hemoglobin concentration ≥20 g/L is common but rarely clinically significant in our population of Arizona rattlesnake bite patients. Methods Poison center records of rattlesnake bites in humans from 2018 through 2022 were retrospectively reviewed and assessed for major bleeding by the above criteria. Results Four hundred and eighty-one patients met the inclusion criteria, of whom 265 (55.1%) had a hemoglobin concentration decrease ≥20 g/L. No patients died, and there was no evidence of bleeding into a critical organ. Three patients (1.1%) received blood transfusions. A decrease in hemoglobin concentration ≥20 g/L was 100% sensitive for identifying the major bleeding-associated outcomes; however, specificity was only 45.2%. Measures of healthcare utilization and chronic sequelae were somewhat higher in patients with a decrease in hemoglobin concentration ≥20 g/L. Discussion Laboratory manifestations of hemotoxicity were common in this population, but hemorrhage was rare. While over half of patients met the major bleeding criterion of a decline in hemoglobin concentration ≥20 g/L, only 1.1% had bleeding that was potentially life-threatening as measured by receipt of a red blood cell transfusion. None died or had bleeding into a critical area. While nonspecific for major bleeding, a drop in hemoglobin concentration correlated with worse envenomation severity: these patients received more vials of antivenom, had a higher medical bill, a longer hospital stay, and were less likely to report full recovery at 90 days. Conclusions A decrease in hemoglobin concentration ≥20 g/L should not be used as evidence of major bleeding for Arizona rattlesnake envenomation studies, but it may have a role as an indirect marker of envenomation severity.

Evaluation of the Role of Neutrophil to Lymphocyte Ratio, Platelet to Lymphocyte Ratio and Mean Platelet Volume as Predictors of the Outcome in Patients with Hemotoxic Snake Bite: A Prospective Study on Patients in Poison Control Centers Ain Shams University Hospitals and Assiut University Hospitals

Abstract Background Snakebite envenomation is considered a major health problem especially in developing centuries. Snakebite envenomation cause major morbidities, disabilities and mortalities. Novel biomarkers as; neutrophils to lymphocytes Ratio (NLR) and plateletto lymphocytes Ratio (PLR)are hematological inflammatory indices that can be a guide for diagnosis, prognosis of the snakebite envenomation. Methodology This was a prospective case control study, which was carried out on 60 hemotoxic snake bite envenomed patients that admitted at Poisoning Control Center AinShams University Hospitals (PCCAUH) and Assiut University Hospitals (AUH) in the period from 1st of July 2019 to 31st of October 2021. In addition, 60 healthy volunteers were used as control subjects. The study aimed to evaluate the role of NLR, PLR and Mean Platelet Volume (MPV) at admission as predictors of the outcome in patients with hemotoxic snakebite envenomation. The patients were divided into mild, moderate and severe groups according to severity of snake envenomation. Result Sixty hemotoxic snake bite envenomed patients (28 patients admitted at PCC-ASUH and 32 admitted at AUH), were divided into (38.4%) mild, (31.6%) moderate and (30%) severe groups according to the severity of snake envenomation. Maximum incidence was found in male (95%) from rural areas (80%) and were farmers (43.3%) from total cases. It was observed that bite was more frequent at lower limbs (70%), outdoors (81.6%), at night (51%) and during autumn season (43.3%). It was found that there was significant positive correlation between NLR at admission and duration of hospitalization, PLR, creatine phosphokinase (CPK) level and whitebloodcells (WBCs) count. While, significant negative correlation was found between NLR and prothrombin concentration (PC), red blood cells(RBCs) and plateletcounts. Also, significant positive correlation was found between PLR at admission and duration of hospitalization, NLR, CPK level and platelets count. Inaddition, significant positive correlation was found between MPV and PT. About 47 (78.33%) patients had complete recovery and about 13 (21.67%) patients recovered with complications including; local complications in (21.67%), systemic complications in (13.33%) and chronic complications In (5%). There were no recorded deaths in the study. It was found that hemotoxic snake bit eenvenomed patients Admitted at PCC-ASUH were significantly more severe,required more antivenom vials and more intensive care unit(ICU) admission than those admitted at AUH. Conclusion NLR and PLR values at admission were significantly high in hemotoxic snake bite envenomed patients and can be used as predictors for diagnosis and prognosis of hemotoxic snake envenomation.In addition, NLR and PLR had significant association with severity of envenomation, duration of hospitalization.

The geographical distribution of scorpions, implication of venom toxins, envenomation, and potential therapeutics in Southern and Northern Africa.

Scorpions are predatory arachnids whose venomous sting primarily affects people in tropical and subtropical regions. Most scorpion stings can only cause localized pain without severe envenomation. Less than one-third of the stings cause systemic envenoming and possibly lead to death. About 350,000 scorpion stings in Northern Africa are recorded yearly, resulting in about 810 deaths. In Eastern/Southern Africa, there are about 79,000 stings recorded yearly, resulting in 245 deaths. Farmers and those living in poverty-stricken areas are among the most vulnerable to getting stung by scorpions. However, compared to adults, children are at greater risk of severe envenomation. Scorpion venom is made up of complex mixtures dominated by peptides and proteins that confer its potency and toxicity. These venom toxins have intra- and interspecies variations associated with the scorpion's habitat, sex, diet, and age. These variations alter the activity of antivenoms used to treat scorpion sting envenomation. Thus, the study of the proteome composition of medically important scorpion venoms needs to be scaled up along their geographical distribution and contributions to envenomation in Southern and Northern Africa. This will help the production of safer, more effective, and broad-spectrum antivenoms within these regions. Here, we review the clinical implications of scorpion sting envenomation in Southern and Northern Africa. We further highlight the compositions of scorpion venoms and tools used in scorpion venomics. We discuss current antivenoms used against scorpion sting envenomation and suggestions for future production of better antivenoms or alternatives. Finally, we discuss the therapeutic properties of scorpion venom.

Investigating Snake-Venom-Induced Dermonecrosis and Inflammation Using an Ex Vivo Human Skin Model.

Snakebite envenoming is a neglected tropical disease that causes >100,000 deaths and >400,000 cases of morbidity annually. Despite the use of mouse models, severe local envenoming, defined by morbidity-causing local tissue necrosis, remains poorly understood, and human-tissue responses are ill-defined. Here, for the first time, an ex vivo, non-perfused human skin model was used to investigate temporal histopathological and immunological changes following subcutaneous injections of venoms from medically important African vipers (Echis ocellatus and Bitis arietans) and cobras (Naja nigricollis and N. haje). Histological analysis of venom-injected ex vivo human skin biopsies revealed morphological changes in the epidermis (ballooning degeneration, erosion, and ulceration) comparable to clinical signs of local envenoming. Immunostaining of these biopsies confirmed cell apoptosis consistent with the onset of necrosis. RNA sequencing, multiplex bead arrays, and ELISAs demonstrated that venom-injected human skin biopsies exhibited higher rates of transcription and expression of chemokines (CXCL5, MIP1-ALPHA, RANTES, MCP-1, and MIG), cytokines (IL-1β, IL-1RA, G-CSF/CSF-3, and GM-CSF), and growth factors (VEGF-A, FGF, and HGF) in comparison to non-injected biopsies. To investigate the efficacy of antivenom, SAIMR Echis monovalent or SAIMR polyvalent antivenom was injected one hour following E. ocellatus or N. nigricollis venom treatment, respectively, and although antivenom did not prevent venom-induced dermal tissue damage, it did reduce all pro-inflammatory chemokines, cytokines, and growth factors to normal levels after 48 h. This ex vivo skin model could be useful for studies evaluating the progression of local envenoming and the efficacy of snakebite treatments.

Development and Efficacy of the Antivenom Specific to Severe Envenomations in Morocco and North Africa: Advancements in Scorpion Envenomation Management.

Scorpion envenomation poses a global public health issue, with an estimated 1,500,000 cases worldwide annually resulting in 2600 deaths. North Africa, particularly Morocco, experiences severe envenomations, mainly attributed to Androctonus mauretanicus and Buthus occitanus in Morocco, and Buthus occitanus and Androctonus australis hector in Algeria and Tunisia, with case numbers often underestimated. Current treatment relies mainly on symptomatic approaches, except in Morocco, where management is limited to symptomatic treatment due to controversies regarding specific treatment. In Morocco, between 30,000 and 50,000 scorpion envenomation cases are reported annually, leading to hundreds of deaths, mainly among children. Controversies among clinicians persist regarding the appropriate course of action, often limiting treatments to symptomatic measures. The absence of a specific antivenom for the venoms of the most lethal scorpions further exacerbates the situation. This study aims to address this gap by developing a monovalent antivenom against the endemic and most dangerous scorpion, Androctonus mauretanicus. The antivenom was produced by immunizing albino rabbits with a mixture of Androctonus mauretanicus venom collected from high-risk areas in Morocco. Immunizations were performed by subcutaneous injections at multiple sites near the lymphatic system, following an immunization schedule. Production control of neutralizing antibody titers was conducted through immunodiffusion. Once a sufficient antibody titer was achieved, blood collection was performed, and the recovered plasma underwent affinity chromatography. The efficacy of purified IgG was evaluated by determining the ED50 in mice, complemented by histological and immunohistochemical studies on its ability to neutralize venom-induced tissue alterations and the neutralization of toxins bound to receptors in the studied organs. The monovalent antivenom demonstrated specificity against Androctonus mauretanicus venom and effective cross-protection against the venom of the scorpions Buthus occitanus and Androctonus australis hector, highly implicated in lethal envenomations in the Maghreb. This study shows that the developed monovalent antivenom exhibits notable efficacy against local scorpions and a surprising ability to neutralize the most lethal envenomations in North Africa. These results pave the way for a new, more specific, and promising therapeutic approach to countering severe scorpion envenomations, especially in Morocco, where specific treatment is lacking.

Pediatric bee sting envenomation with multiorgan challenge: A case report

Bee stings commonly result in minor reactions, but severe cases can lead to systemic complications including anaphylaxis and multiorgan dysfunction. We present a case of an 8-year-old child experiencing severe bee sting envenomation, manifesting as various organ dysfunctions including acute kidney injury and acute pancreatitis. Renal replacement therapy was effective in managing renal dysfunction. Further research is warranted to explore targeted antivenom therapies for severe bee sting reactions. Prompt recognition and a multidisciplinary approach are crucial for successful management. Further research into specific treatments is needed to improve outcomes in such cases.

Effect of Seaweed-Derived Fucoidans from Undaria pinnatifida and Fucus vesiculosus on Coagulant, Proteolytic, and Phospholipase A2 Activities of Snake Bothrops jararaca, B. jararacussu, and B. neuwiedi Venom.

Snakebite envenomation (SBE) causes diverse toxic effects in humans, including disability and death. Current antivenom therapies effectively prevent death but fail to block local tissue damage, leading to an increase in the severity of envenomation; thus, seeking alternative treatments is crucial. This study analyzed the potential of two fucoidan sulfated polysaccharides extracted from brown seaweeds Fucus vesiculosus (FVF) and Undaria pinnatifida (UPF) against the fibrinogen or plasma coagulation, proteolytic, and phospholipase A2 (PLA2) activities of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom. The toxicity of FVF and UPF was assessed by the hemocompatibility test. FVF and UPF did not lyse human red blood cells. FVF and UPF inhibited the proteolytic activity of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom by approximately 25%, 50%, and 75%, respectively, while all venoms led to a 20% inhibition of PLA2 activity. UPF and FVF delayed plasma coagulation caused by the venoms of B. jararaca and B. neuwiedi but did not affect the activity of B. jararacussu venom. FVF and UPF blocked the coagulation of fibrinogen induced by all these Bothropic venoms. FVF and UPF may be of importance as adjuvants for SBE caused by species of Bothrops, which are the most medically relevant snakebite incidents in South America, especially Brazil.

Snakebite envenoming: A systematic review and meta-analysis of global morbidity and mortality.

Snakebite envenoming represents a significant and often neglected public health challenge, particularly in rural communities across tropical and subtropical regions. An estimated 1.2-5.5 million people are envenomed by snakebites annually. More than 125,000 of these bites are fatal, and 3-4 times as many results in disability/disfigurement. Despite its prevalence, collecting accurate epidemiological data on snakebite is challenging. This systematic review and meta-analysis collates global epidemiology data on snakebite morbidity and mortality. Medline, Embase, Cochrane and CINAHL Plus databases were searched for articles published between 2001-2022. Pooled incidence and mortality were obtained using random effects modelling, heterogeneity (I2) was tested, and sensitivity analyses performed. Newcastle-Ottawa Scale assessed study quality. Out of the four databases, 5,312 articles were found. After removing duplicates, 3,953 articles were screened by title and abstract and 65 articles containing information on snakebite epidemiology, encompassing 663,460 snakebites, were selected for analysis. The people most at risk for snakebite were men (59%), engaged in agricultural labour (27.5%), and residing in rural areas (66.7%). More than half (57%) of the reported bites resulted in envenoming. Incidents occurred frequently in the summer season (38.5%), during daytime (56.7%), and bites were most often to the lower limb (56.4%). Envenoming severity was frequently mild (46.7%), treated in hospital (68.3%), and was treated with anti-venom (64.7%). The pooled global incidence and mortality was 69.4 /100,000 population (95%CI: 36.8 to 101.9) and 0.33/100,000 population (95%CI, 0.14 to 0.52) per year, respectively. Stratified by continents, Asia had the highest incidence of 130.7/100,000 population (95%CI: 48.3 to 213.1) while Europe has the lowest with 0.7/100,000 population (95%CI: -0.2 to 1.5). The highest mortality was reported in Asia at 0.96/100,000 population (95% CI: 0.22 to 1.70), and Africa 0.44/100,000 population (95%CI: -0.03 to 0.84). Incidence was highest among inhabitants of lower-middle-income countries 132.7/100,000 population (95%CI: 55.4 to 209.9) while mortality was highest in low-income countries at 0.85/100,000 population (95% CI: -0.06 to 2.31). Incidence and mortality rates noted here highlight the global impact of snakebite and underscore the critical need to address the burden of snakebite envenoming. It also reveals that while reported snakebite incidence was higher in lower-middle-income countries, the burden of mortality was greatest among inhabitants of low-income countries, again emphasising the need for greater efforts to tackle this neglected tropical disease.

Biochemical and biological characterization of the venoms of Naja kaouthia and Naja mandalayensis from Myanmar and neutralization effects of BPI cobra antivenom

Snakebite is a neglected public health issue, with many scientific and medical issues to be solved. Cobras are among the most common venomous snakes in Myanmar and are responsible for a considerable number of severe snakebite envenoming. There are three species of cobra (Naja kaouthia, Naja mandalayensis and Ophiophagus hannah) in Myanmar. The study aims to characterize the N. kaouthia and N. mandalayensis venoms and to investigate the efficacy of anti-cobra antivenom (BPI) against the two venoms. Protein components and fibrinogenolytic activity were determined by SDS-PAGE. Enzymatic activities for PLA2, protease and acetylcholinesterase were determined by spectrophotometric method. Anticoagulant activity was determined by recalcification time of citrated human plasma. Myotoxicity, necrotizing activity, median lethal dose (LD50) and median effective dose (ED50) were determined by WHO recommended methods. The SDS-PAGE displayed the proteins and enzymes containing in two venoms were different. N. kaouthia venom exhibited more in PLA2, acetylcholinesterase, anticoagulant, fibrinogenolytic and necrotizing activities than N. mandalayensis venom. N. mandalayensis venom had more protease activity and myotoxicity than N. kaouthia venom. The median lethal dose (LD50) of N. kaouthia and N. mandalayensis venom was 4.33 μg/mouse and 5.04 μg/mouse respectively. Both venoms induced fibrinogen Aα chain degradation in 30 min (N. kaouthia) and in 6 h (N. mandalayensis). The same median effective dose (ED50) (19.56 μg/mouse) showed that anti-NK antivenom can neutralize against lethal effect of N. mandalayensis venom. It can also neutralize the protease activity, anticoagulant activity and fibrinogenolytic activity of both venoms. Immunodiffusion and immunoblotting studies showed that the antivenom recognized its homologous venom (N. kaouthia) and cross-reacted against the heterologous venom (N. mandalayensis). The anti-NK antivenom is suitable to use for N. mandalayensis bite if monospecific antivenom is not available.

VENOMOUS ENCOUNTER: A CASE REPORT ON SNAKE BITE DURING FULL-TERM GESTATION WITH DELAYED MANIFESTATION

Background: Snake bite is uncommon among pregnant women, that too presentation in third trimester with late presentation, with envenomation is rare. Knowledge about the toxic symptoms and management of snake bite poisoning is very low due the rarity of cases. Case report: Presenting a case of 26 year old female, Primigravida with Premature Rupture of Membranes with Snake bite in Acute Kidney Injury with Disseminate Intravascular Coagulopathy. Appropriate care and management led to the survival of both mother and baby. Discussion: In India, 216 snake species exist, 52 are venomous. Elapids like cobras, kraits, vipers, and sea snakes pose threats. Venom potency varies with seasons and snake color. Envenomation symptoms include local pain, systemic effects, and coagulopathy. Pregnancy complicates management antivenom and careful monitoring are vital. Conclusion: Acute kidney injury with disseminated intravascular coagulopathy arising from systemic poisoning due to snake bite in pregnancy is difficult and challenging. Obstetric and medical line of treatment depends on the severity of envenomation, gestational age at presentation, timing, duration and quality of treatment.

Evaluation of optimum dose of anti-snake venom required and its outcome based on severity of envenomation in snakebite case

Background: Snakebite is an important occupational hazard in India as it is always been a land of poisonous snakes. The isssue which the physician confronts while treating a snake bite patient is assesment of degree of envenomation and requirement of ASV dose. Aims and Objectives: This study was taken to evaluate the optimum dose of anti-snake venom (ASV) required based on the severity of envenomation. Materials and Methods: Patients with a history of snakebite brought to the Department of General Medicine, Hassan, were included in this study. The study was conducted during the period from December 2014 to June 2016. The sample size of 80 patients was included in the study after fulfilling the inclusion criteria. Results: A total of 80 patients were included in the study. The majority of the victims were males (70%), age between 21 and 40 years (47.5%), and agriculture was the main occupation (67.3%). 51.25% did not identify the snake. The most poisonous were viper and cobra types which were 36.5% and 12.5%, respectively. A delay in lag time of 8.99±8.2 h was observed in severe envenomation. Overall, 51 cases (63.75%) had cellulitis, and 3 (3.75%) in the severe group required fasciotomy. Twenty percent had hematologic derangements. Ten percent of patients had developed renal failure and one required dialysis. 8.75% of patients developed respiratory failure and all required mechanical ventilation. The average dose of ASV vials used in mild, moderate, and severe envenomation was 9.04±3.51 vials, 18.5±5.27 vials, and 28.6±7.30 vials, respectively. The overall mortality rate was 5%. Conclusions: The optimum dose of ASV required in mild, moderate, and severe envenomation is 9.04±3.51 vials, 18.5±5.27 vials, and 28.6±7.30 vials, respectively to neutralize the circulating venom and lower the risk of development of serious complications.

Use of Antibiotics following Snakebite in the Era of Antimicrobial Stewardship.

Even though there are guidelines for the management of snakebite envenoming (SBE), the use of antibiotics in this pathology remains controversial. The aim of this study is to provide a narrative review of the literature and recommendations based on the best available evidence regarding antibiotic use in SBE. We performed a narrative review of relevant literature regarding SBE and antibiotic use as prophylaxis or treatment. A total of 26 articles were included. There is wide use of antibiotics in SBE; nevertheless, infection was not necessarily documented. The antibiotics used varied according to the study, from beta lactams to lincosamide and nitroimidazoles, and from monotherapy to combined antimicrobials. The most common recommendations were to manage skin and soft tissue infections and avoid infectious complications, but these suggestions are not necessarily based on bacteriological findings. Prophylactic use of antibiotics in SBE is discouraged in most studies. Antibiotic prescription in SBE should be based on the susceptibility of microorganisms isolated from the affected tissue or identified in snakes' oral cavities. Antibiotics should be reserved only for patients with a demonstrated infection, or those at a high risk of developing an infection, i.e., presenting severe local envenoming, local signs of infection, or those with incorrect manipulation of wounds. Prospective studies are needed to correlate microbiological findings at the wound site and the response to antibiotic use.

Geographic distribution of the scorpion fauna in the central Moroccan region of Souss-Massa with potential implications for public health

Despite the medical importance of North African scorpions, many aspects of their ecology which may be important to understand envenoming patterns throughout their range, remain understudied. The region of Souss-Massa in central Morocco exhibits a high incidence of scorpion envenomings, with 29 437 cases reported between 2005 and 2010, resulting in 32 deaths. In the present study, we provide an updated inventory of scorpions occurring throughout the Souss-Massa region, with additional information about their distribution and notes on preferred habitats for each species observed. Sampling was carried out at 39 stations over a three-year period: June and August 2020, April and June 2022, and July and August 2023. Twelve species belonging to two families were recovered over the course of the study. The families Buthidae and Scorpionidae were represented by eleven and a single species respectively. Overall, this represents 71% of all species reported to occur in the Souss-Massa region. Apart from Androctonus mauritanicus, A. bourdoni, A. sergenti and Hottentotta gentili which are present in and around human dwellings, all other species were found in uninhabited areas. Apart from Scorpio mogadorensis, all the species of scorpions we recovered can cause severe envenomation with potentially fatal outcomes. Field-based ecological investigations should be encouraged to gain a more accurate and comprehensive understanding of scorpion distribution patterns and habitat preference. In turn, this will inform the health-science community of the etiological factors responsible for scorpion envenoming.

Impact of tourniquet use on severity of snakebite envenoming in Chongqing, China: a single-center retrospective study.

To identify risk factors associated with snakebite severity and determine whether tourniquet use can affect the severity and outcome of snakebites. The clinical data of patients who sustained limb snakebites from 1 March 2021 to 31 October 2022 were reviewed. The patients were divided into three groups according to snakebite severity: mild (517 cases), moderate (112 cases), and severe (8 cases). We compared the clinical data of mild versus moderate to severe snakebites. Multivariate logistic regression was used to determine the independent risk factors for moderate to severe snakebites. The study involved 637 patients. There were statistically significant differences in age, tourniquet use, onset time, white blood cell increase, platelet decrease, creatine kinase (CK) increase, activated partial thromboplastin time shortening, and length of stay between patients with mild snakebites and those with moderate to severe snakebites. Multivariate logistic regression analysis showed that age, tourniquet use, and CK increase were independent risk factors for moderate to severe snakebites. The overall severity of snakebites in Chongqing is mild, and the prognosis is good. Age, tourniquet use, and CK increase are independent risk factors for the severity of snakebites. We do not recommend tourniquet use after snakebites in Chongqing.

Systematic review and meta-analysis on the efficacy of Indian polyvalent antivenom against the Indian snakes of clinical significance.

Snakebite in India is a severe problem as it causes a mortality rate of 58,000 and a disability rate of 140,000 every year which is the highest among any other country. Antivenom is the primary therapy for snakebite, and its manufacturing techniques have essentially stayed unaltered for over a century. Indian polyvalent antivenom, a scientifically validated medicine for treating the toxic effects of snakebites, is available against the venom of the so-called Big Four snakes namely Spectacled cobra (Naja naja), Saw-scaled viper (Echis carinatus), Russell's viper (Daboia russelli) and the Common krait (Bungarus caeruleus), responsible for majority of the deaths in India. India hosts many other species of snakes, including cobras, kraits, saw-scaled vipers, sea snakes, and pit vipers, responsible for clinically severe envenomation. Neutralization strategy has been applied to access the efficacy of antivenoms, crucial for reducing snake bite deaths and disabilities. This review aims to conduct a systematic review and meta-analysis on the neutralization efficiency of the Polyvalent Antivenom (PAV) and focus on the factors that may contribute to the poor recognition of the antivenom towards the venom toxins. Reports focusing on the investigation of antivenom efficacy were searched and collected from several databases. Preclinical studies that reported the neutralization efficacy of the commercial antivenom against the medically important snakes of India were included. The articles were screened based on the inclusion criteria and 8 studies were shortlisted for meta-analysis. Pooled proportion was calculated for the antivenom efficacy reported by the studies and was found to be statistically significant with a 95% confidence interval. The heterogenicity in the venom toxicity and neutralization potency of the antivenom was evident in the overall estimate (proportion) and individual data. We provide comprehensive evidence on antivenom efficacy against medically important snakes from various parts of India which may aid in identifying the gaps in snake envenomation therapy and the need for novel potentially improved treatment of snakebites.

Structural, biochemical and immunochemical characterization of an acidic phospholipase A2 from Lachesis acrochorda (Viperidae: Crotalinae) venom

Viperids of the genus Lachesis, also known as bushmasters, are capable of injecting great amounts of venom that cause severe envenomation incidents. Since phospholipases type A2 are mainly involved in edema and myonecrosis within the snakebite sites, in this work, the isolation, amino acid sequence and biochemical characterization of the first phospholipase type A2 from the venom of Lachesis acrochorda, named Lacro_PLA2, is described. Lacro_PLA2 is an acidic aspartic 49 calcium-dependent phospholipase A2 with 93% similarity to the L. stenophrys phospholipase. Lacro_PLA2 has a molecular mass of 13,969.7 Da and an experimental isoelectric point around 5.3. A combination of N-terminal Edman degradation and MS/MS spectrometry analyses revealed that Lacro_PLA2 contains 122 residues including 14 cysteines that form 7 disulfide bridges. A predicted 3D model shows a high resemblance to other viperid phospholipases. Nevertheless, immunochemical and phospholipase neutralization tests revealed a notorious level of immunorecognition of the isolated protein by two polyclonal antibodies from viperids from different genus, which suggest that Lacro_PLA2 resembles more to bothropic phospholipases. Lacro_PLA2 also showed significantly high edema activity when was injected into mice; so, it could be an alternative antigen in the development of antibodies against toxins of this group of viperids, seeking to improve commercial polyclonal antivenoms.