Search Results (382)

Snakebite envenomation (SBE) is a major public health issue in sub-Saharan Africa (SSA), particularly in Cameroon. This Phase IV, multicenter, open-label study was conducted from June 2024 to December 2024 to evaluate the safety and efficacy of PANAF-Premium™, a World Health Organization (WHO)-approved polyvalent antivenom that was introduced in Cameroon in 2023, given that prospectively gathered data and studies on this antivenom’s safety in SSA are limited. In total, 130 victims admitted to four district hospitals in North Cameroon with confirmed SBE were included. Data on envenomation syndromes, clinical outcomes, adverse events, and treatment response were recorded. Echis species were responsible for most bites, while clinical syndromes included hemotoxic (68.5%), cytotoxic (30.8%), and neurotoxic (0.8%) presentations. On average, victims required 3.34 vials and 5.55 days for clinical recovery. Early antivenom administration significantly reduced the number of antivenom vials required to manage the symptoms (p = 0.003) and hospital stay (p = 0.049). Seventeen patients experienced mild to moderate adverse events. Two deaths and a case of kidney injury were noted, all unrelated to antivenom use. These study findings indicate the safety and effectiveness of PANAF-Premium™ antivenom, meeting WHO performance targets. The results highlight the importance of timely antivenom administration in treating SBEs. Full article

The saw-scaled viper Echis carinatus, one of the “Big Four” causes of snakebites in India, is found from Sri Lanka to eastern Iraq. To investigate clinical reports regarding the limited efficacy of Indian polyvalent antivenom (IPAV) against envenomation in Echis carinatus sochureki (ECS) in northwestern India, we obtained 22 snakes from three locations in Rajasthan and identified 148–174 toxin isoforms belonging to 21–25 toxin families in their venom using a bottom-up proteomics approach. All samples showed a high abundance of snake venom metalloproteinases (SVMPs), particularly SVMP class III. Other major components were phospholipases A₂, L-amino-acid oxidases, snake venom serine proteases and snaclecs (C-type lectins). Variation in venom composition among locations in Rajasthan, compared to E. c. carinatus (ECC) from southern India, was primarily due to differences in the relative abundance of these toxin families. Recognition of all venom components by IPAV was poor at lower antivenom concentrations. Notably, SVMP classes II and III were poorly recognized at all venom-to-antivenom ratios in all ECS venoms, and a plasma clotting assay revealed poor neutralization of procoagulant activity. This collaborative study highlights the need for the development of regional antivenoms to effectively treat snakebites in northwestern India. Full article

Background: Cobras (Naja sp.) are medically important snakes in Thailand. Envenoming by the monocled cobra (N. kaouthia) often causes neurotoxicity, most notably ptosis, ophthalmoplegia, local tissue necrosis and progressive paralysis leading to respiratory failure. Early antivenom administration and respiratory support are medically significant for effective treatment. Methods: In this study, we determined the association between the time course of cobra envenoming and related neurotoxic outcomes using the clinical profiles of cobra envenomed patients. We also demonstrated histopathological changes in the neuromuscular junction of the diaphragm in experimentally envenomed rats. Results: A retrospective study of 69 cases of cobra envenoming in Central and Southern Thailand shows that delayed arrival beyond one hour at hospital was common among younger adults (47.0% aged 10–29) and associated with more severe neurotoxicity, including higher rates of ptosis (41.2%, p = 0.032) and referrals (41.2% vs. 15.4%, p = 0.040). Antivenoms (22 Monovalent and 1 Polyvalent) were administered to 23 (33.3%) envenomed victims and caused adverse reactions in 9 cases (39.1%). Neurotoxicity following cobra envenoming in the clinical section correlated with histopathological examination of envenomed rat diaphragms. Transmission electron microscopy (TEM) revealed degeneration of the neuromuscular junction and diaphragm within 1 h following experimental cobra envenomation, which worsened by 4 h. Intravenous administration of antivenom at recommended doses reduced diaphragmatic damage but failed to prevent presynaptic degeneration after 90 min of envenoming. Conclusions: Clinically, extraocular muscle paralysis was the earliest manifestation. Early monitoring and prompt administration of antivenom are essential to reduce neurotoxicity and relevant complications. Full article

Vipera aspis envenomation represents a potentially life-threatening condition in dogs, particularly in rural or semi-rural areas of Central Italy, where this species is endemic. This case report describes the clinical presentation, diagnostic findings, therapeutic management, and outcome of a dog bitten by Vipera aspis in the Umbria region. At admission, the dog exhibited mild fever, localized swelling, pain at the bite site, and mild systemic clinical signs. Antivenom was not administered, and the dog was managed with supportive and medical therapy aimed at controlling inflammation, preventing secondary infection, and monitoring systemic involvement. The clinical course was favorable, and the dog recovered without complications. As this report describes a single clinical case, no conclusions regarding treatment efficacy can be drawn. However, this case provides additional clinical information on the management and outcome of Vipera aspis envenomation in dogs. Full article

We present the case of a Vipera ammodytes ammodytes (Vaa, nose-horned viper)-bitten patient with recurrent thrombocytopenia. A 53-year-old patient envenomated by Vaa experienced three episodes of venom-dependent thrombocytopenia (4, 57 and 11 × 10⁹/L), all of which we managed with antivenom Fab fragments. Despite these three severe episodes of thrombocytopenia within 24 h, platelet function remained intact, as demonstrated by normal thromboelastometry and aggregometry (96, 126, and 150 U) results after antivenom was administered and the platelet count normalized. Furthermore, flow cytometry showed only 0.3–1.7% expression of P-selectin on platelets, indicating that platelets did not activate but remained functional during and after thrombocytopenia. We assessed platelet function using rotational thromboelastometry, which evaluates the overall kinetics of hemostasis, including clot formation and stability. We performed aggregometry, which also reflects platelet function, only when the platelet count was within the normal range. Flow cytometry quantified P-selectin expression as a key marker of platelet activation. This case demonstrates that a component of Vaa venom can repeatedly induce venom-dependent thrombocytopenia, which is reversible by intervention, while platelet function remains intact. Full article

Background: Although antivenom is the standard treatment for snakebite envenoming, its efficacy may be impacted by geographic variation in venom composition, emphasizing the need for region-specific antivenom development. Methods: We report a case of snakebite envenoming, in which the patient was bitten on the hand by a captive Malayan pit viper (Calloselasma rhodostoma) with typical clinical manifestations following. Antivenom (produced in Thailand) was administered at 33 and 39 h post-bite. Venom from the causative individual snake was collected for compositional analysis via SDS-PAGE. Enzymatic activity of the venom was evaluated through the degradation of casein and phospholipid substrates, along with the assessment of enzymatic inhibition by two regionally specific antivenoms produced in Vietnam (AV. Cr. VN.) and Thailand (AV. Cr. TL.). Results: The patient showed good recovery, with complete normalization by day 7. SDS-PAGE profiling of the venom revealed five major enzymes, with SVSP, SVMP and PLA₂ being the most abundant (16.7%, 40.11% and 26.11%, respectively). Antivenom inhibition tests revealed remaining casein percentages of 67.43% (AV. Cr. VN) and 59.35% (AV. Cr. TL). Blood agar assays indicated that phospholipase activity was reduced to 21.01% by AV. Cr. VN. and 23.30% by AV. Cr. TL. Conclusions: Our results show that the Vietnamese antivenom generated greater inhibitory activity against proteinases compared to the Thai product, underscoring the importance of using regionally specific antivenoms that are more effective against the venom profiles of locality-matched snake populations. Full article

In Brazil, snakebites are a critical health issue, particularly in the state of Roraima, where Bothrops species account for the majority of cases. Snake venoms contain multifunctional toxins that cause life-threatening systemic complications and complex wounds, often resulting in permanent disabilities. Although antivenoms have reduced lethality, they fail to prevent the rapid and prolonged action of tissue-damaging toxins at the bite site. As a result, snakebite management is characterized by prolonged hospitalizations and high healthcare costs. Therefore, effective management of these complex wounds is crucial to improving patient outcomes. This article presents a series of four clinical cases involving Bothrops snakebite patients treated at the General Hospital of Roraima. Each case describes the progression of the injury, clinical challenges, interventions, and outcomes. Vacuum-Assisted Wound Therapy (VAWT) was employed as a key component of treatment in all cases, promoting faster granulation tissue formation, infection control, and reduced risk of amputation. The use of VAWT demonstrated significant improvements in wound healing compared to conventional treatment approaches. These findings highlight the potential benefits of VAWT in managing complex snakebite-related wounds, especially in severe cases with high risks of complications. However, barriers such as the high cost of therapy and limited access in remote and resource-poor regions must be addressed to enable broader clinical application. Full article

Background: In Europe, Vipera ammodytes ammodytes (Vaa, nose-horned viper) is considered the most venomous of the European vipers. The antivenom Viperfav^®, composed of polyvalent equine F(ab′)₂ fragments, is effective against Vipera aspis, Vipera berus and Vaa. Objectives: This study aimed to evaluate the clinical efficacy and pharmacokinetics of Viperfav in Vaa envenomations. Methods: Patients presenting with Vaa snakebite and treated with intravenous Viperfav were included. Clinical manifestations and laboratory findings were assessed on admission to the Emergency Department, prior to antivenom therapy, and monitored throughout hospitalization. Blood samples were collected on arrival and at defined intervals after Viperfav administration. Venom and antivenom concentrations in serum were determined by ELISA and subjected to pharmacokinetic analysis. Results: Twenty-one patients bitten by Vaa and classified with a severity score of 2b on the modified Audebert clinical severity scale received a single intravenous dose of Viperfav within 4 h of the bite. Viperfav attenuated the progression of local symptoms and prevented the development of new systemic manifestations. The serum concentrations of F(ab′)₂ fragments reached 196 µg/mL, far exceeding the venom concentration at admission (35 ng/mL). The prolonged elimination half-life of Viperfav (49 h) corresponded with the absence of recurrent symptoms after a single dose. Bradycardia or hypotension occurred in 10% of patients; no cases of anaphylaxis or serum sickness were observed. Conclusions: A single intravenous dose of Viperfav demonstrated clinical efficacy and a favourable pharmacokinetic profile in Vaa envenomed patients when administered within hours of the bite. Full article

Venomous snakes constitute ecologically significant and medically relevant organisms due to the risks associated with their bites, which frequently result in secondary infections. The oral microbiota of these reptiles plays a crucial role in the pathogenesis of such infections; however, its diversity and clinical implications remain insufficiently characterized. This is the first comprehensive review to systematically trace the methodological evolution in snake oral microbiota research, documenting the paradigm shift from traditional culture-dependent techniques to advanced culture-independent approaches, including next-generation sequencing and metagenomics. Our analysis uniquely demonstrates the transformative impact of these technological advances on bacterial diversity identification and antimicrobial resistance gene detection in venomous species. Environmental factors, captivity conditions, and venom composition significantly influence microbial community structure and resistance profiles. These intricate interactions are essential for improving clinical management of snakebite infections, informing empirical antibiotic therapy protocols, and guiding antivenom production strategies. Additionally, the potential of snake oral microbiota as a source of novel bioactive compounds represents an emerging area of bioprospecting research. This review uniquely bridges microbiology, venomics, and clinical medicine, demonstrating the necessity for integrative, multidisciplinary approaches to fully elucidate the ecological and biomedical significance of oral microbial communities in venomous snakes. Full article

Snakebite envenomation by Bothrops species is a neglected tropical disease and a major cause of local tissue damage and disability in Latin America. Antivenom therapy is effective against systemic effects but fails to prevent local myonecrosis, inflammation, and pain. This study evaluated photobiomodulation therapy (PBMT) using infrared (808 nm) alone or in combination with red (660 nm) laser in a murine model of Bothrops leucurus envenomation. A single PBMT session was applied, and animals were evaluated at 24 and 72 h. Combined treatment significantly reduced edema, hyperthermia, plasma CK and LDH, restored nociceptive thresholds, and improved motor recovery compared with infrared alone. Principal component analysis demonstrated clustering of combined-treatment animals with negative controls, supporting a synergistic therapeutic effect. These findings highlight dual-wavelength PBMT as a promising adjunctive approach to antivenom, directly targeting local venom-induced pathology. Full article

Snakebite envenoming is a neglected tropical disease contributing to a significant number of morbidities and mortalities globally. Reports indicate that venom variation influences antivenom efficacy, which might affect treatment outcomes. The venom composition of Daboia russelii (Russell’s viper), one of the big four snakes in India, has been extensively studied from different geographical regions of India. Nonetheless, the Russell’s viper venom proteome from Kerala (Western Ghats region), together with its study in comparison with the same species’ venom from Tamil Nadu, has not been explored yet. In the current study, Daboia russelii venom from Irula (RVi) and the Western Ghats region in Kerala (RVwg) was characterized through mass spectrometry-based proteomics and few functional assays. The proteomics study identified 52 proteins from 14 snake protein families in RVi and 61 proteins from 17 snake venom protein families in RVwg. Some of the protein families, including DNase and hyaluronidase, as well as vascular endothelial growth factor, were exclusively identified in RVwg venom. Comparative functional analysis indicated that RVwg exhibited higher fibrinogenolytic and hyaluronidase activities, while RVi venom showed higher phospholipase A₂ and L-amino acid oxidase activities. Through ELISA, RVi venom showed an end-point titration value of 1:24,300 for all the antivenoms used in this study, whereas for RVwg, compared to PSAV (Premium serums and vaccines) (1:2700), Virchow and VINS (both 1:8100) antivenoms showed better immunological cross-reactivity. Immunoblotting experiments indicated differential binding and recognition of antigenic epitopes present in both venoms by the polyvalent antivenoms used in the current study. All these findings highlight that the venom proteome varies according to the geographical location, and this significantly influences antivenom efficacy. Full article

The puff adder (Bitis arietans) is a clinically relevant viper species found throughout Africa, and it is responsible for a greater incidence of health-related envenomations than all other snake species on the continent combined. Unresolved skeletal muscle damage is a common consequence of B. arietans envenomation that can result in long-term morbidity and even death. Antivenom treatment can mitigate the systemic effects of the venom but offers little protection against local tissue damage. Identifying the mechanisms through which B. arietans venom induces tissue damage and impedes skeletal muscle regeneration could identify possible treatment alternatives that could help alleviate the long-term consequences of envenomation. Skeletal muscle has an innate ability to regenerate, but constituents within the venom can impede multiple stages of this regeneration process. In this study, we employed a combination of biochemical analyses, cell-based assays, and in vivo experiments to assess the toxicological implications of B. arietans envenomation and its impacts on key processes of regeneration. Our findings demonstrate that the pathological characteristics of permanent muscle damage resulting from B. arietans envenomation may be attributed to the venom’s effects on muscle stem cell precursors, the extracellular matrix (ECM), and the influence of blood-borne proteins that promote fibrosis. Full article

Nanodiamonds (NDs) are an innovative material in biomedical applications based on their excellent biocompatibility, nanoscale dimensions, and high surface area. In this study, we evaluated the potential of ND-in-oil emulsion to induce potent antibody responses in animals immunized with cobra venom. NDs demonstrated the capacity to bind complex venom proteins as stable conjugates, well dispersed in aqueous solution. Immunization of mice with cobra venom incorporated with ND-in-oil emulsion adjuvant (ND/venom) elicited strong venom-specific antibody responses with titers comparable to those induced by venom formulation with conventional Freund’s adjuvants (FA/venom). IgG subclass analysis revealed that ND- and FA-based formulations induced a Th2-biased immune response in mice. Moreover, antibodies elicited by ND/venom or FA/venom immunization specifically recognized the epitopes of the lethal component of short-chain neurotoxin and conferred full protection against lethal cobra venom challenge (3LD₅₀). Further, ND/venom hyperimmunization was capable of inducing high levels of neutralizing antibodies in larger animals, rabbits, highlighting the potential for antivenom manufacturing. Notably, there were no obvious lesions at the injection sites of animals that received ND/venom, in contrast to those that received FA/venom. These findings indicated NDs as an effective and safe additive in venom formulation for antivenom production. Full article