Acidente crotálico seguido por primeiro episódio psicótico: um folclore clínico / Rattlesnake bite accident followed by first psychotic episode: a clinical folklore / Accidente crotálico seguido de primer episodio psicótico: un folclore clínico

Introdução: Acidentes ofídicos são doenças negligenciadas e constituem uma parcela importante da morbidade de pessoas em idade produtiva que vivem em zonas rurais. A maior parte dos seus efeitos a curto prazo é amplamente conhecida, especialmente aqueles de natureza clínica; no entanto, ainda se observa lacuna importante do conhecimento das consequências a longo prazo de tais agravos, notadamente as de ordem psíquica. Este artigo relata um caso de adoecimento mental subsequente a um acidente crotálico e gera reflexões de âmbito cultural e fisiopatológico a respeito das sequelas de tais eventos. Apresentação do caso: Trata-se de adolescente residente no interior baiano que foi vítima de mordedura por cascavel e teve necessidade de hospitalização em unidade de terapia intensiva. Observou-se que, mesmo após melhora clínica, iniciou com sintomas psicóticos prodrômicos e progrediu para piora mental grave, que culminou em internação psiquiátrica e diagnóstico de esquizofrenia no decorrer dos meses seguintes. Conclusões: Nota-se, neste caso, correlação direta entre esses dois eventos; mas, em razão da escassez de trabalhos científicos que abordem tais questões, depreende-se que é preciso investigar e estudar com maior profundidade possíveis associações entre acidentes crotálicos e psicoses.

Introduction: Snakebites are neglected diseases and constitute an important part of the morbidity of working-age people who live in rural areas. Most of their short-term effects are widely known, especially those of a clinical nature; however, there is still an important gap in the knowledge of the long-term consequences of such injuries, notably those of a psychotic nature. This article aims to report a case of mental illness subsequent to a rattlesnake bite accident and generate cultural and pathophysiological reflections regarding the consequences of such events. Case presentation: An adolescent residing in the interior of the state of Bahia was bitten by a rattlesnake and required hospitalization in an intensive care unit. It was observed that even after clinical improvement, the case started with prodromal psychotic symptoms and progressed to severe mental deterioration that culminated in psychiatric hospitalization and diagnosis of schizophrenia over the following months. Conclusions: In this case, there was a direct correlation between these two events, but because of the scarcity of scientific works that address such issues, it is necessary to investigate and study in greater depth possible associations between snakebite accidents and psychoses.

Introducción: Las mordeduras de serpientes son enfermedades desatendidas y constituyen una parte importante de la morbilidad de las personas en edad laboral que viven en zonas rurales. La mayoría de sus efectos a corto plazo son ampliamente conocidos, especialmente los de carácter clínico; sin embargo, todavía existe un importante vacío en el conocimiento de las consecuencias a largo plazo de este tipo de lesiones, en particular las de carácter psíquico. Este artículo tiene como objetivo informar un caso de enfermedad mental posterior a un accidente crotálico y generar reflexiones culturales y fisiopatológicas sobre las consecuencias de tales eventos. Presentación del caso: Se trata de un adolescente residente en el interior de Bahía que fue mordido por una serpiente cascabel y requirió hospitalización en unidad de cuidados intensivos. Se observó que, aún después de la mejoría clínica, comenzó con síntomas psicóticos prodrómicos y progresó a un deterioro mental severo que culminó con hospitalización psiquiátrica y diagnóstico de esquizofrenia en los meses siguientes. Conclusiones: En este caso, existe una correlación directa entre estos dos eventos pero, debido a la escasez de trabajos científicos que aborden tales cuestiones, parece necesario investigar y estudiar con mayor profundidad posibles asociaciones entre accidentes crotálicos y psicosis.

Evaluation of the Inhibitory Potential of Synthetic Peptides Homologous to CDR3 Regions of a Monoclonal Antibody against Bothropic Venom Serine Proteases.

Snakebite accidents, neglected tropical diseases per the WHO, pose a significant public health threat due to their severity and frequency. Envenomation by Bothrops genus snakes leads to severe manifestations due to proteolytic enzymes. While the antibothropic serum produced by the Butantan Institute saves lives, its efficacy is limited as it fails to neutralize certain serine proteases. Hence, developing new-generation antivenoms, like monoclonal antibodies, is crucial. This study aimed to explore the inhibitory potential of synthetic peptides homologous to the CDR3 regions of a monoclonal antibody targeting a snake venom thrombin-like enzyme (SVTLE) from B. atrox venom. Five synthetic peptides were studied, all stable against hydrolysis by venoms and serine proteases. Impressively, four peptides demonstrated uncompetitive SVTLE inhibition, with Ki values ranging from 10-6 to 10-7 M. These findings underscore the potential of short peptides homologous to CDR3 regions in blocking snake venom toxins, suggesting their promise as the basis for new-generation antivenoms. Thus, this study offers potential advancements in combatting snakebites, addressing a critical public health challenge in tropical and subtropical regions.

Does Covid-19 influence the dynamics of envenomation by animals in a country strongly affected by both conditions? Epidemiological data from Brazil.

The impact of Covid-19 on envenomations by venomous animals in countries heavily affected by both conditions has not been quantified yet. Brazil shows high incidence of envenomations by scorpions, spiders and snakes and was heavily affected by waves of Covid-19. To determine how the pandemic impacted the epidemiology of envenomations by those three groups of venomous animals, we used online databases from two surveillance sources on number of cases and mortality. During the years before and during the pandemic, scorpion stings typically occurred in adults of both sexes in urban zones in the Southeast and Northeast regions. Spider bites occurred mainly in the South region, in adults of both sexes in urban zone. Snakebites affected mainly rural adult men in the Amazon. Between 2007 and 2021, overall incidence of cases by scorpions, spiders and snakes decreased after the beginning of the pandemic, snakebites did not show changes after the pandemic started in Brazil, but cases by scorpions and spiders decreased. No changes in the incidence of deaths were observed. On national level, Covid-19 affected some demographic, clinical and epidemiological aspects in cases by scorpions, spiders and snakes.

Viperidae snake envenomation from a highly complex hospital in southwestern Colombia.

Background: Snake envenomation is a medical condition with high morbidity and mortality in southwestern Colombia. Objectives: To describe the characteristics of the envenomation caused by Viperidae snakes view in a highly complex hospital in Southwestern Colombia. Methods: A cross-sectional study was carried out. Patients treated for Viperidae snake envenomation from 2001 to 2020 in a Hospital Fundación Valle del Lili, Cali, Colombia, were studied. Results: Twenty-eight patients were included. Envenomation was caused by the genera Bothrops, Bothriechis, Porthidium, and Bothrocophias. The median age was 37.7 (±20.6), and they were predominantly male (19, 68%). Bites occurred on the upper extremities in 16 (57%) patients. Pain (23, 81%) and edema (22, 78%) were the most common clinical symptoms. Thirteen (46%) patients presented coagulopathy. Prolonged prothrombin and activated partial thromboplastin times were common: (22, 78% and 15, 53%, respectively). Twenty (71%) patients were treated with polyvalent antivenom (median dose of 6 (2-15) vials). The median time between the accident and antivenom administration was 9 h (5.5-17). Door-to-needle time was 37.5 (0-62) min. Eighteen (64%) patients were admitted to the intensive care unit. Three (11%) patients had serum sickness. Seven (25%) developed infectious complications, four (14%) had surgery, one (3%) had compartment syndrome, one (3%) underwent amputation of the affected limb, and one (3%) patient died. Conclusions: Local manifestations and coagulopathy were common clinical features. Polyvalent antivenom was an effective treatment for disease control. Significant complications were associated with delays in seeking medical care.

Snakebites epidemiology in Mexico: a 13-year ecological analysis.

BACKGROUND: Globally, snakebites have a significant impact on public health and represent substantial costs for health services. Their severity is particularly relevant in developing countries due to the lack of resources and accessibility to health facilities. Additionally, the number of cases may be underestimated, highlighting the urgent need for improved prevention measures. METHODS: An observational ecological study was undertaken using the records identified with X200-X209 codes registered in the Ministry of Health injuries database during 2010-2022. Variables included information related to the patient, the snakebite and the healthcare provided. Statistical analysis was carried out with STATA 16 and Microsoft Excel 2020. RESULTS: A total of 10 420 snakebites were registered. The average number of cases per year was 788 (IQR 615, 875) and 82.74% occurred during the rainy season. The median age was 35 (IQR 19, 52) y and early adulthood was the most affected age group; bites were most common on the hand and in the living place. The Eastern region of Mexico registered the highest number of cases, with 3496 (33.71%) of snakebites. The lethality rate was 18.23 per 10 000. CONCLUSIONS: Snakebites are a significant health problem in Mexico. Most injuries occur among men in early adulthood, in households and in the upper extremities.

Evaluation of the inhibitory potential of synthetic peptides homologous to CDR3 regions of a monoclonal antibody against Bothropic venom serine proteases

Snakebite accidents, neglected tropical diseases per the WHO, pose a significant public health threat due to their severity and frequency. Envenomation by Bothrops genus snakes leads to severe manifestations due to proteolytic enzymes. While the antibothropic serum produced by the Butantan Institute saves lives, its efficacy is limited as it fails to neutralize certain serine proteases. Hence, developing new-generation antivenoms, like monoclonal antibodies, is crucial. This study aimed to explore the inhibitory potential of synthetic peptides homologous to the CDR3 regions of a monoclonal antibody targeting a snake venom thrombin-like enzyme (SVTLE) from B. atrox venom. Five synthetic peptides were studied, all stable against hydrolysis by venoms and serine proteases. Impressively, four peptides demonstrated uncompetitive SVTLE inhibition, with Ki values ranging from 10−6 to 10−7 M. These findings underscore the potential of short peptides homologous to CDR3 regions in blocking snake venom toxins, suggesting their promise as the basis for new-generation antivenoms. Thus, this study offers potential advancements in combatting snakebites, addressing a critical public health challenge in tropical and subtropical regions.

Preliminary Insights of Brazilian Snake Venom Metalloproteomics.

Snakebite envenoming is one of the most significantly neglected tropical diseases in the world. The lack of diagnosis/prognosis methods for snakebite is one of our motivations to develop innovative technological solutions for Brazilian health. The objective of this work was to evaluate the protein and metallic ion composition of Crotalus durissus terrificus, Bothrops jararaca, B. alternatus, B. jararacussu, B. moojeni, B. pauloensis, and Lachesis muta muta snake venoms. Brazilian snake venoms were subjected to the shotgun proteomic approach using mass spectrometry, and metal ion analysis was performed by atomic spectrometry. Shotgun proteomics has shown three abundant toxin classes (PLA2, serine proteases, and metalloproteinases) in all snake venoms, and metallic ions analysis has evidenced that the Cu2+ ion is present exclusively in the L. m. muta venom; Ca2+ and Mg2+ ions have shown a statistical difference between the species of Bothrops and Crotalus genus, whereas the Zn2+ ion presented a statistical difference among all species studied in this work. In addition, Mg2+ ions have shown 42 times more in the C. d. terrificus venom when compared to the average concentration in the other genera. Though metal ions are a minor fraction of snake venoms, several venom toxins depend on them. We believe that these non-protein fractions are capable of assisting in the development of unprecedented diagnostic devices for Brazilian snakebites.

Inflammatory Profile Associated with Secondary Infection from Bothrops atrox Snakebites in the Brazilian Amazon.

Bothrops snakebite envenomation (SBE) is consider an important health problem in Brazil, where Bothrops atrox is mainly responsible in the Brazilian Amazon. Local effects represent a relevant clinical issue, in which inflammatory signs and symptoms in the bite site represent a potential risk for short and long-term disabilities. Among local complications, secondary infections (SIs) are a common clinical finding during Bothrops atrox SBE and are described by the appearance of signs such as abscess, cellulitis or necrotizing fasciitis in the affected site. However, the influence of SI in the local events is still poorly understood. Therefore, the present study describes for the first time the impact of SBE wound infection on local manifestations and inflammatory response from patients of Bothrops atrox SBE in the Brazilian Amazon. This was an observational study carried out at the Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus (Brazil), involving victims of Bothrops SBE. Clinical and laboratorial data were collected along with blood samples for the quantification of circulating cytokines and chemokines before antivenom administrations (T0) and 24 h (T1), 48 h (T2), 72 h (T3) and 7 days after (T4). From the 94 patients included in this study, 42 presented SI (44.7%) and 52 were without SI (NSI, 55.3%). Patients classified as moderate envenoming presented an increased risk of developing SI (OR = 2.69; CI 95% = 1.08-6.66, p = 0.033), while patients with bites in hands showed a lower risk (OR = 0.20; CI 95% = 0.04-0.96, p = 0.045). During follow-up, SI patients presented a worsening of local temperature along with a sustained profile of edema and pain, while NSI patients showed a tendency to restore and were highlighted in patients where SI was diagnosed at T2. As for laboratorial parameters, leukocytes, erythrocyte sedimentation ratio, fibrinogen and C-reactive protein were found increased in patients with SI and more frequently in patients diagnosed with SI at T3. Higher levels of circulating IL-2, IL-10, IL-6, TNF, INF-γ and CXCL-10 were observed in SI patients along with marked correlations between these mediators and IL-4 and IL-17, showing a plurality in the profile with a mix of Th1/Th2/Th17 response. The present study reports for the first time the synergistic effects of local infection and envenoming on the inflammatory response represented by local manifestations, which reflected on laboratorial parameters and inflammatory mediators and thus help improve the clinical management of SI associated to Bothrops SBE.

Snakebites from the standpoint of an indigenous anthropologist from the Brazilian Amazon.

Conflicting attempts between indigenous caregivers trying to exercise their healing practices in hospitals have been recorded in the Brazilian Amazon. In this work, we present an interview with the Baniwa indigenous anthropologist Francy Baniwa. In an external and colonial interpretation, it was previously stated that indigenous people attribute the origin of snakebites as supernatural and that indigenous medicine, when it saves a patient from complications and death, has symbolic efficacy. In this interview, we observed that this form of interpretation is asymmetric because, for indigenous people, their understanding of nature is broader than ours, with more possibilities of ways of existence, including non-human entities as well or ill-intentioned as humans. The interaction of humans with these identities produces a form of existence with its own clinical reality, which is full of symbolism. Effective communication between health agents and indigenous patients and caregivers must undergo this exercise of otherness and interculturality.

The Colombian bushmasters Lachesis acrochorda (García, 1896) and Lachesis muta (Linnaeus, 1766): Snake species, venoms, envenomation, and its management.

In Colombia, there are two species of bushmaster snakes, Lachesis acrochorda, which is distributed mainly in the west of the country (in the Choco region), and Lachesis muta in the southeast (in the Amazon and Orinoquia region), whose presence has been reduced due to the destruction of their habitats. Captive maintenance is challenging, making it difficult to obtain their venom for study and antivenom manufacturing. They are the largest vipers in the world. The occurrence of human envenomation is quite rare, but when it occurs, it is associated with high mortality. Bushmaster venom is necrotizing, hemorrhagic, myotoxic, hemolytic, and cardiovascular depressant. Due to the presence of bradycardia, hypotension, emesis, and diarrhea in some patients (Lachesis syndrome), the possibility of a vagal or cholinergic effect is raised. The treatment of envenomation is hindered by the scarcity of antivenom and the need to use high doses. A review of the most relevant biological and medical aspects of bushmaster snakes is presented, mainly for those occurring in Colombia, to facilitate their recognition and raise awareness about the need for special attention to improve their conservation and advance scientific knowledge, in particular, about their venom.

Envenomation by Micrurus hemprichii in Brazilian Amazonia: A report of three cases.

Herein, we report three new separate cases of human envenomations by Micrurus hemprichii for the Amazon, which is a biome where envenomations by Micrurus are seldom reported. Two women were bitten after stepping on the snakes and one man was bitten while handling the animal. All cases occurred in the peridomicile, in rural areas. The first case evolved mainly to local symptoms, but the patient was discharged before the identification of the snake and had to be called back for observation before being eventually discharged. In the second case, the patient presented transitory dyspnea and she was discharged after four days in hospital. In the third case, the patient showed only local symptoms, but he was about to receive unnecessary antivenom against coral snakes. Cases like these show the importance of educational problems regarding local venomous snakes in order to avoid bites and to provide the correct hospital treatment. For this, trained professionals in cases involving venomous animals are needed.

Hipernocicepção induzida por veneno de serpentes Bothrops jararaca: uma revisão de literatura

Since the beginning of humanity, man has experienced the subjectivity and complexity of pain, an essential phenomenon for the preservation of physical integrity. Pain processing occurs by transmission, transduction, modulation and perception of stimuli capable of activating nociceptors. There are many substances that activate nociceptors, among them are animal venoms, such by snakes, which have a highly complex composition. In Brazil, the most important snakes belong to the genus Bothrops. Conventional treatment with antivenom is effective against systemic symptoms, but not very effective in controlling local lesions, such as edema and pain. The main actions of Bothrops venoms are in hemostasis and inflammation, the latter condition being responsible for causing the sensitization of nociceptors. Some venom substances are involved in inflammation and hypernociception, including jararhagin, a metalloprotease present in Bothrops jararaca venom (BjV). Through a literature review, we seek to understand the mechanisms that leads to hypernociception caused by BjV. The scientific literature regarding the mediation of pain induced by BjV is scarce, even more so in relation to sex differences, a variable little considered in the genesis and treatment of the lesions observed after envenomation by these snakes. Thus, further studies are needed to elucidate the mechanisms involved in hypernociception resulting from the Bothrops jararaca snakebites, with the aim of mapping this phenomenon and, in the future, seeking complementary therapies to the conventional one in the treatment of these symptoms.

Desde o surgimento da humanidade o homem vivencia a subjetividade e complexidade da dor, fenômeno essencial para a preservação da integridade física. O processamento da dor ocorre pela transmissão, transdução, modulação e percepção de estímulos capazes de ativar os nociceptores. Muitas são as substâncias que ativam os nociceptores, dentre elas estão os venenos animais, como por exemplo de serpentes, que possuem uma composição altamente complexa. No Brasil, as serpentes de maior importância pertencem ao gênero Bothrops. O tratamento convencional com antiveneno é efetivo contra as reações sistêmicas, porém pouco eficaz no controle das lesões locais, como edema e dor. As principais ações dos venenos botrópicos são na hemostasia e inflamação, sendo essa última condição responsável por causar a sensibilização dos nociceptores. Algumas toxinas dos venenos estão envolvidas na inflamação e hipernocicepção, dentre elas a jararagina, uma metaloprotease presente no veneno de Bothrops jararaca (vBj). Por meio de uma revisão de literatura buscamos compreender os mecanismos que levam a hipernocicepção causada pelo vBj. A literatura científica a respeito da mediação da dor promovida pelo vBj é escassa, mais ainda, em relação às diferenças sexuais, uma variável pouco considerada na gênese e no tratamento das lesões observadas após o envenenamento por essas serpentes. Desta forma, mais estudos são necessários para elucidar os mecanismos envolvidos na hipernocicepção decorrente da picada de serpentes Bothrops jararaca, com o intuito de mapear esse fenômeno e futuramente buscar terapias complementares à convencional no tratamento desse sintoma.

The severity of acute kidney injury correlates with plasma venom levels in Bothrops atrox envenomings.

The Brazilian Amazon has high rates of snakebite envenomings (SBEs), with ∼90% caused by Bothrops atrox. Envenomings by this species can trigger local and systemic effects, such as acute kidney injury (AKI). Our aim was to identify predictors of AKI in Bothrops SBEs in patients from Manaus, Western Brazilian Amazon. A total of 127 patients were enrolled, with a predominance of men between 16 and 45 years old from rural areas. Of the 127 patients, 38.6% developed AKI, with 61.2% presenting stage I, 34.7% presenting stage II and 4.1% presenting stage III severity. The age groups 0-10 years and ≥60 years presented a significantly higher frequency of AKI compared to the 11-40 years group. Moderate/severe edema in the affeccted limb was significantly associated with lower risk of AKI [p = 0.01; OR = 0.11 (95%CI 0.02-0.53)]. Nausea [p = 0.01; OR = 54.44 (95%CI = 3.26-909.27)] and high blood urea levels [p = 0.01; OR = 5.38 (95%CI = 2.12-13.66)] were risk factors for AKI. There was a significant positive correlation between circulating venom levels and the highest creatinine serum values during the hospital stay (p = 0.03) and with the difference between the maximum creatinine levels and the creatinine levels on admission (p = 0.02). A positive correlation between serum venom concentrations and creatinine levels suggests a direct or indirect dose-dependent participation of the venom toxins in the pathogenesis of AKI.

Diversity of Phospholipases A2 from Bothrops atrox Snake Venom: Adaptive Advantages for Snakes Compromising Treatments for Snakebite Patients.

The evolution of snake venoms resulted in multigene toxin families that code for structurally similar isoforms eventually harboring distinct functions. PLA2s are dominant toxins in viper venoms, and little is known about the impact of their diversity on human envenomings and neutralization by antivenoms. Here, we show the isolation of three distinct PLA2s from B. atrox venom. FA1 is a Lys-49 homologue, and FA3 and FA4 are catalytic Asp-49 PLA2s. FA1 and FA3 are basic myotoxic proteins, while FA4 is an acid non-myotoxic PLA2. FA3 was the most potent toxin, inducing higher levels of edema, inflammatory nociception, indirect hemolysis, and anticoagulant activity on human, rat, and chicken plasmas. FA4 presented lower anticoagulant activity, and FA1 had only a slight effect on human and rat plasmas. PLA2s presented differential reactivities with antivenoms, with an emphasis on FA3, which was not recognized or neutralized by the antivenoms used in this study. Our findings reveal the functional and antigenic diversity among PLA2s from B. atrox venom, highlighting the importance of assessing venom variability for understanding human envenomations and treatment with antivenoms, particularly evident here as the antivenom fails to recognize FA3, the most active multifunctional toxin described.

Plant-Derived Toxin Inhibitors as Potential Candidates to Complement Antivenom Treatment in Snakebite Envenomations.

Snakebite envenomations (SBEs) are a neglected medical condition of global importance that mainly affect the tropical and subtropical regions. Clinical manifestations include pain, edema, hemorrhage, tissue necrosis, and neurotoxic signs, and may evolve to functional loss of the affected limb, acute renal and/or respiratory failure, and even death. The standard treatment for snake envenomations is antivenom, which is produced from the hyperimmunization of animals with snake toxins. The inhibition of the effects of SBEs using natural or synthetic compounds has been suggested as a complementary treatment particularly before admission to hospital for antivenom treatment, since these alternative molecules are also able to inhibit toxins. Biodiversity-derived molecules, namely those extracted from medicinal plants, are promising sources of toxin inhibitors that can minimize the deleterious consequences of SBEs. In this review, we systematically synthesize the literature on plant metabolites that can be used as toxin-inhibiting agents, as well as present the potential mechanisms of action of molecules derived from natural sources. These findings aim to further our understanding of the potential of natural products and provide new lead compounds as auxiliary therapies for SBEs.

Venomous animals in a changing world.

The climatic changes of the next decades will modify human and livestock interactions with venomous animals; Some venomous species will disappear in the coming decades; Other venomous species will shift their distributions or increase their geographic ranges invading new countries that may not have specific antivenoms.

Estudo dos exemplares de serpentes Crotalus durissus trazidos por pacientes picados: insights sobre a relação entre a ecologia da espécie e a epidemiologia dos acidentes

Snakebites are a global public health issue, being considered by the World Health Organization a neglected tropical disease. In Brazil, the second snake that most accidents is the rattlesnake, Crotalus durissus, which has a high lethality rate. A greater understanding of how species ecology, for example reproductive biology, can relate to the occurrence and epidemiology of accidents is important for health. Since this knowledge can provide important data for the development of prevention and combat measures, as well as environmental education strategies. In this study, retrospective data contained in the entry forms of the Laboratory of Zoological Collections on crotalic accidents seen at the Hospital Vital Brazil, whose patients brought the specimens that caused the bites, were analyzed. Some specimens of rattlesnakes were dissected and statistical calculations were performed to investigate the correlation between the ecology and epidemiology of the cases. It could be observed that several epidemiological characteristics coincide with previous works. The results of this study showed that the seasonality of accidents may be related not only to human activity, but also to reproductive events of the species, such as: the high occurrence of accidents in autumn, coinciding with the period of mating and combat between males, in spring and summer, coinciding with the period of gestation and parturition in females, leading to greater exposure of snakes and, consequently, greater probability of encounter between humans and animals. The frequency of accidents with offspring in relation to adults is probably related to other characteristics of the natural history, such as feeding, since reproductive events do not influence the activity and exposure of this ontogenetic stage. Therefore, this study shows the importance of investigating the specimens that cause bites, as well as the ecology of snakebites, requiring further studies to investigate this species, as well as other snakes that cause accidents from a new ecological perspective.

Os acidentes ofídicos são uma questão de saúde pública a nível global, sendo considerada pela Organização Mundial da Saúde uma doença tropical negligenciada. No Brasil, a segunda serpente que mais causa acidentes é a cascavel, Crotalus durissus, a qual possui um elevado índice de letalidade. Uma maior compreensão sobre como a ecologia da espécie, por exemplo a biologia reprodutiva, pode se relacionar com a ocorrência e a epidemiologia dos acidentes é importante para a saúde. Uma vez que esse conhecimento pode trazer dados importantes para o desenvolvimento de medidas de prevenção e combate, assim como estratégias de educação ambiental. Neste trabalho, foram analisados dados retrospectivos dos acidentes crotálicos atendidos no Hospital Vital Brazil, contidos nos livros de registros da Coleção, dos quais os pacientes trouxeram os exemplares causadores das picadas. Alguns exemplares da espécie foram dissecados e foram realizadas cálculos estatísticos para investigar a correlação entre a ecologia e a epidemiologia dos casos. Pôde-se observar que várias características epidemiológicas coincidem com trabalhos anteriores. Os resultados deste estudo mostraram que a sazonalidade dos acidentes pode estar relacionada não só a atividade humana, como também a eventos reprodutivos da espécie, tais como: a elevada ocorrência de acidentes no outono coincidindo com o período de acasalamento e combate entre machos, na primavera e verão coincidindo com o período de gestação e parturição nas fêmeas, levando a uma maior exposição das serpentes e, consequentemente, maior probabilidade de encontro entre humanos e animais. A frequência de acidentes com filhotes em relação aos adultos, provavelmente, está relacionada a outras características da história natural, como a alimentação, visto que os eventos reprodutivos não influenciam na atividade e exposição desse estágio ontogenético. Portanto, esse trabalho mostra a importância da investigação de exemplares causadores das picadas, como também a ecologia dos acidentes ofídicos, sendo necessário mais estudos que investiguem essa espécie, como também as outras serpentes causadoras de acidentes sob uma nova perspectiva ecológica.

The severity of acute kidney injury correlates with plasma venom levels in Bothrops atrox envenomings

The Brazilian Amazon has high rates of snakebite envenomings (SBEs), with ∼90% caused by Bothrops atrox. Envenomings by this species can trigger local and systemic effects, such as acute kidney injury (AKI). Our aim was to identify predictors of AKI in Bothrops SBEs in patients from Manaus, Western Brazilian Amazon. A total of 127 patients were enrolled, with a predominance of men between 16 and 45 years old from rural areas. Of the 127 patients, 38.6% developed AKI, with 61.2% presenting stage I, 34.7% presenting stage II and 4.1% presenting stage III severity. The age groups 0–10 years and ≥60 years presented a significantly higher frequency of AKI compared to the 11–40 years group. Moderate/severe edema in the affeccted limb was significantly associated with lower risk of AKI [p = 0.01; OR = 0.11 (95%CI 0.02–0.53)]. Nausea [p = 0.01; OR = 54.44 (95%CI = 3.26–909.27)] and high blood urea levels [p = 0.01; OR = 5.38 (95%CI = 2.12–13.66)] were risk factors for AKI. There was a significant positive correlation between circulating venom levels and the highest creatinine serum values during the hospital stay (p = 0.03) and with the difference between the maximum creatinine levels and the creatinine levels on admission (p = 0.02). A positive correlation between serum venom concentrations and creatinine levels suggests a direct or indirect dose-dependent participation of the venom toxins in the pathogenesis of AKI.

Diversity of phospholipases A2 from Bothrops atrox snake venom: adaptive advantages for snakes compromising treatments for snakebite patients

The evolution of snake venoms resulted in multigene toxin families that code for structurally similar isoforms eventually harboring distinct functions. PLA2s are dominant toxins in viper venoms, and little is known about the impact of their diversity on human envenomings and neutralization by antivenoms. Here, we show the isolation of three distinct PLA2s from B. atrox venom. FA1 is a Lys-49 homologue, and FA3 and FA4 are catalytic Asp-49 PLA2s. FA1 and FA3 are basic myotoxic proteins, while FA4 is an acid non-myotoxic PLA2. FA3 was the most potent toxin, inducing higher levels of edema, inflammatory nociception, indirect hemolysis, and anticoagulant activity on human, rat, and chicken plasmas. FA4 presented lower anticoagulant activity, and FA1 had only a slight effect on human and rat plasmas. PLA2s presented differential reactivities with antivenoms, with an emphasis on FA3, which was not recognized or neutralized by the antivenoms used in this study. Our findings reveal the functional and antigenic diversity among PLA2s from B. atrox venom, highlighting the importance of assessing venom variability for understanding human envenomations and treatment with antivenoms, particularly evident here as the antivenom fails to recognize FA3, the most active multifunctional toxin described.