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Toxins Nov 2023Snakebite envenomation (SBE)-induced immunity refers to individuals who have been previously bitten by a snake and developed a protective immune response against... (Review)
Review
Snakebite envenomation (SBE)-induced immunity refers to individuals who have been previously bitten by a snake and developed a protective immune response against subsequent envenomations. The notion stems from observations of individuals, including in the indigenous population, who present only mild signs and symptoms after surviving multiple SBEs. Indeed, these observations have engendered scientific interest and prompted inquiries into the potential development of a protective immunity from exposure to snake toxins. This review explores the evidence of a protective immune response developing following SBE. Studies suggest that natural exposure to snake toxins can trigger protection from the severity of SBEs, mediated by specific antibodies. However, the evaluation of the immune memory response in SBE patients remains challenging. Further research is needed to elucidate the immune response dynamics and identify potential targets for therapeutic interventions. Furthermore, the estimation of the effect of previous exposures on SBE epidemiology in hyperendemic areas, such as in the indigenous villages of the Amazon region (e.g., the Yanomami population) is a matter of debate.
Topics: Animals; Humans; Snake Bites; Antivenins; Snakes; Toxins, Biological; Snake Venoms
PubMed: 37999502
DOI: 10.3390/toxins15110638 -
Scientific Reports Dec 2023Snakebite envenoming is a global public health issue that causes significant morbidity and mortality, particularly in low-income regions of the world. The clinical...
Snakebite envenoming is a global public health issue that causes significant morbidity and mortality, particularly in low-income regions of the world. The clinical manifestations of envenomings vary depending on the snake's venom, with paralysis, haemorrhage, and necrosis being the most common and medically relevant effects. To assess the efficacy of antivenoms against dermonecrosis, a preclinical testing approach involves in vivo mouse models that mimic local tissue effects of cytotoxic snakebites in humans. However, current methods for assessing necrosis severity are time-consuming and susceptible to human error. To address this, we present the Venom Induced Dermonecrosis Analysis tooL (VIDAL), a machine-learning-guided image-based solution that can automatically identify dermonecrotic lesions in mice, adjust for lighting biases, scale the image, extract lesion area and discolouration, and calculate the severity of dermonecrosis. We also introduce a new unit, the dermonecrotic unit (DnU), to better capture the complexity of dermonecrosis severity. Our tool is comparable to the performance of state-of-the-art histopathological analysis, making it an accessible, accurate, and reproducible method for assessing dermonecrosis in mice. Given the urgent need to address the neglected tropical disease that is snakebite, high-throughput technologies such as VIDAL are crucial in developing and validating new and existing therapeutics for this debilitating disease.
Topics: Humans; Mice; Animals; Venoms; Snake Bites; Antivenins; Global Health; Necrosis
PubMed: 38066189
DOI: 10.1038/s41598-023-49011-6 -
PLoS Neglected Tropical Diseases Oct 2023Snakebite envenoming remains a public health threat in many tropical countries including Malawi. Traditional healers (THs) have been consulted by victims of snakebites...
Snakebite envenoming remains a public health threat in many tropical countries including Malawi. Traditional healers (THs) have been consulted by victims of snakebites as primary caregivers for millennia. There are no studies in Malawi to understand this phenomenon, therefore, our study aimed to explore the experiences and practices of THs regarding snakebite treatment and prevention in rural Malawi. Between August and September 2022, we conducted semi-structured interviews with 16 THs who were purposefully selected from various locations across Neno District, Malawi. We analysed the interview data using Dedoose software, where we generated codes and grouped them into themes. Out of the 16 THs interviewed, 68.8% (n = 11) were male, and 43.8% were aged between 40 and 60 years. Our study identified five themes: THs' knowledge of snakes and treatment, the continuum of care they provide, payment procedures, snakebite prevention, and their relationship with health facilities. They claimed a good understanding of the snakes in their area, including the seasons with more snakebites, and were confident in their ability to provide treatment, however, this was not scientifically proven. They offered a comprehensive care package, including diagnosis, first aid, main treatment, and follow-up care to monitor the victim's condition and adjust treatment as needed. THs provide free treatment for snakebites or use a "pay later" model of service delivery. All THs claimed a "vaccine" for snakebites that could prevent bites or neutralize the venom. However, no formal relationship existed between THs and Health Care Workers (HCWs). We recommend collaboration between HCWs and THs, establishing clear referral pathways for snakebite victims and educating THs on identifying danger signs requiring prompt referral to healthcare facilities.
Topics: Animals; Humans; Male; Adult; Middle Aged; Female; Snake Bites; Traditional Medicine Practitioners; Malawi; Snakes; First Aid; Antivenins
PubMed: 37792697
DOI: 10.1371/journal.pntd.0011653 -
PLoS Neglected Tropical Diseases Jul 2023Snake bite envenoming (SBE) is one neglected tropical disease that has not received the needed attention. The sequelae of burdensome disability and mortality impact the...
BACKGROUND
Snake bite envenoming (SBE) is one neglected tropical disease that has not received the needed attention. The sequelae of burdensome disability and mortality impact the socioeconomic life of communities adversely with little documentation of SBE in health facility records in Ghana. This study details SBE and snake distribution, habits/habitats, type of venom expressed and clinical manifestations.
METHODOLOGY
We conducted a structured thematic desk review of peer reviewed papers, books and reports from repositories including PubMed, World Health Organization (WHO) and Women's & Children's Hospital (WCH) Clinical Toxinology Resources using bibliographic software EndNote and search engine Google Scholar with the following key words; snakes, medical importance, snake bites, venom and venom type, envenomation, symptoms and signs, vaccines, venom expenditure, strike behaviour and venom-metering + Ghana, West Africa, Africa, World. We also reviewed data from the District Health Information Management System (DHIMS) of the Ghana Health Service (GHS). Outcome variables were organized as follows: common name (s), species, habitat/habit, species-specific toxin, clinical manifestation, antivenom availability, WHO category.
FINDINGS
Snake bites and SBE were grouped by the activity of the expressed venom into neurotoxic, cardiotoxic, haemorrhagic, cytotoxic, myotoxic, nephrotoxic and procoagulants. Neurotoxic snake bites were largely due to elapids. Expressed venoms with cardiotoxic, haemorrhagic, nephrotoxic and procoagulant activities principally belonged to the family Viperidae. Snakes with venoms showing myotoxic activity were largely alien to Ghana and the West African sub-region. Venoms showing cytotoxic activity are expressed by a wide range of snakes though more prevalent among the Viperidae family. Snakes with neurotoxic and haemorrhagic venom activities are prevalent across all the agro-ecological zones in Ghana.
CONCLUSION/SIGNIFICANCE
Understanding the characteristics of snakes and their venoms is useful in the management of SBE. The distribution of snakes by their expressed venoms across the agro-ecological zones is also instructive to species identification and diagnosis of SBE.
Topics: Animals; Antivenins; Elapid Venoms; Elapidae; Ghana; Snake Bites; Snake Venoms; Snakes; Viperidae
PubMed: 37506181
DOI: 10.1371/journal.pntd.0011050 -
International Journal of Public Health 2023This study aimed to determine the current status of the knowledge of diagnosis and treatment of snakebites among medical staff in China and its influencing factors. A...
This study aimed to determine the current status of the knowledge of diagnosis and treatment of snakebites among medical staff in China and its influencing factors. A cross-sectional survey of 12,581 medical staff was conducted in 12 provinces in China between June 2022 and February 2023. We analyzed the results using descriptive statistics, T-tests or analysis of variance, and a generalized linear model. The average score of snakebite diagnosis and treatment knowledge among medical staff in China was 3.15 ± 2.15 out of a total score of 12. Through a generalized linear regression model, we found that gender, occupation, region, hospital level, work department, work tenure, training received in the diagnosis and treatment of snakebite, experience in snakebite diagnosis and treatment, availability of antivenom in the unit, and self-evaluation of snakebite treatment ability all affected the medical staff's scores of snakebite diagnosis and treatment knowledge. The knowledge level of snakebite diagnosis and treatment among Chinese medical staff is generally low, so it is imperative to conduct standardized snakebite diagnosis and treatment training for medical staff.
Topics: Humans; Antivenins; China; Cross-Sectional Studies; Snake Bites; Clinical Competence
PubMed: 38146482
DOI: 10.3389/ijph.2023.1606601 -
PLoS Neglected Tropical Diseases Jul 2023Snakebite is one of the most neglected tropical diseases. In Ghana, there has been a limited interest in snakebite envenoming research despite evidence of high...
INTRODUCTION
Snakebite is one of the most neglected tropical diseases. In Ghana, there has been a limited interest in snakebite envenoming research despite evidence of high human-snake conflicts. In an effort to meet the World Health Organisation's (WHO) 2030 snakebite targets, the need for research evidence to guide policy interventions is evident. However, in setting the research agenda, community and healthcare workers' priorities are rarely considered.
METHODS
Three categories of focus groups were formed in the Ashanti and Upper West regions of Ghana, comprising of community members with and without a history of snakebite and healthcare workers who manage snakebite patients. Two separate focus group discussions were conducted with each group in each region. Using the thematic content analysis approach, the framework method was adopted for the data analysis. A predefined 15-item list of potential snakebite-associated difficulties and the WHO's 2030 snakebite strategic key activities were ranked in order of priority based on the participants' individual assessment.
RESULTS
Both acute and chronic effects of snakebite such as bite site management, rehabilitation and mental health were prioritised by the community members. Health system challenges including training, local standard treatment protocols and clinical investigations on the efficacy of available antivenoms were identified as priorities by the healthcare workers. Notably, all the participant groups highlighted the need for research into the efficacy of traditional medicines and how to promote collaborative strategies between traditional and allopathic treatment practices.
CONCLUSION
The prioritisation of chronic snakebite envenoming challenges by community members and how to live and cope with such conditions accentuate the lack of post-hospital treatment follow-ups for both mental and physical rehabilitation. To improve the quality of life of patients, it is essential to involve grassroots stakeholders in the process of developing and prioritising future research agenda.
Topics: Animals; Humans; Snake Bites; Ghana; Quality of Life; Antivenins; Snakes
PubMed: 37478151
DOI: 10.1371/journal.pntd.0011504 -
Journal of Tropical Medicine 2024Snakebite envenomation (SBE) constitutes a public health, social, and economic problem affecting poor communities in intertropical and subtropical regions. This review... (Review)
Review
Snakebite envenomation (SBE) constitutes a public health, social, and economic problem affecting poor communities in intertropical and subtropical regions. This review sought to synthesize literature on snakebite envenomation in Benin to highlight research perspectives and strategies for better management of the menace. A literature search performed in multidisciplinary electronic databases showed that the prevalence of SBE is high in Benin, but the incidences, associated morbidities, and mortalities are greatly underestimated. Most snake envenomations are by in Northern Benin during the rainy season. Adults involved in agricultural activities are the most affected. The absence of antivenin serum in the most affected areas explains the preference for alternative and traditional medicine as the first-line treatment for SBE in Benin. In conclusion, it would be imperative to revitalize the snakebite reporting system in order to have better epidemiological data and to develop a sustainable national strategy for the control and management of snakebite envenomation.
PubMed: 38623180
DOI: 10.1155/2024/8357312 -
PLoS Neglected Tropical Diseases Apr 2024Snakebite envenoming represents a significant and often neglected public health challenge, particularly in rural communities across tropical and subtropical regions. An... (Meta-Analysis)
Meta-Analysis
BACKGROUND
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.
METHODS
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.
RESULTS
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).
CONCLUSION
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.
Topics: Male; Humans; Female; Snake Bites; Antivenins; Incidence; Asia; Prevalence
PubMed: 38574167
DOI: 10.1371/journal.pntd.0012080 -
Toxicon : Official Journal of the... Aug 2023In recent years it has become possible to design snakebite antivenoms with diverse pharmacokinetic properties. Owing to the pharmacokinetic variability of venoms, the...
In recent years it has become possible to design snakebite antivenoms with diverse pharmacokinetic properties. Owing to the pharmacokinetic variability of venoms, the choice of antivenom scaffold may influence a treatment's neutralisation coverage. Computation offers a useful medium through which to assess the pharmacokinetics and pharmacodynamics of envenomation-treatment systems, as antivenoms with identical neutralising capacities can be simulated. In this study, we simulate envenomation and treatment with a variety of antivenoms, to define the properties of effective antivenoms. Systemic envenomation and treatment were described using a two-compartment pharmacokinetic model. Treatment of Naja sumatrana and Cryptelytrops purpureomaculatus envenomation was simulated with a set of 200,000 theoretical antivenoms across 10 treatment time delays. These two venoms are well-characterised and have differing pharmacokinetic properties. The theoretical antivenom set varied across molecular weight, dose, k, k, and valency. The best and worst treatments were identified using an area under the curve metric, and a global sensitivity analysis was performed to quantify the influence of the input parameters on treatment outcome. The simulations show that scaffolds of diverse molecular formats can be effective. Molecular weight and valency have a negligible direct impact on treatment outcome, however low molecular weight scaffolds offer more flexibility across the other design parameters, particularly when treatment is delayed. The simulations show k to primarily mediate treatment efficacy, with rates above 10 Ms required for the most effective treatments. k has the greatest impact on the performance of less effective scaffolds. While the same scaffold preferences for improved treatment are seen for both model snakes, the parameter bounds for C. purpureomaculatus envenomation are more constrained. This paper establishes a computational framework for the optimisation of antivenom design.
Topics: Animals; Antivenins; Snake Bites; Snakes; Pharmacokinetics; Snake Venoms
PubMed: 37356552
DOI: 10.1016/j.toxicon.2023.107206 -
Toxicon : Official Journal of the... Jul 2024African cobras (Naja species) represent one of the most encountered medically important snakes in Africa. They are classified as African spitting (Afronaja subgenus) and... (Review)
Review Comparative Study
African cobras (Naja species) represent one of the most encountered medically important snakes in Africa. They are classified as African spitting (Afronaja subgenus) and non-spitting cobras (Uraeus and Boulengerina subgenera) with similar and different characteristics. Snake venom toxins including three-finger toxin (3FTx), phospholipase A2 (PLA), and snake venom metalloproteinase (SVMP) cause snakebite envenomation leading to morbidity and mortality. The profile of the proteome of African cobra venoms will help to develop safer and more effective antivenoms. The approval of Captopril by the US Food and Drug Administration (FDA) for the treatment of cardiovascular diseases, has led to intensified research towards possible use of venom toxins as therapeutics. In this review, we compare the venom proteome profile of 3 African Naja subgenera. In both Afronaja and Boulengerina subgenera, 3FTx (Afronaja-69.79%; Boulengerina-60.56%) followed by PLA (Afronaja-21.15%; Boulengerina-20.21%) dominated the venoms compared to the Uraeus subgenus dominated by 3FTx (84.55%) with little to no PLA abundance (0.8%). The venom of subgenus Uraeus was distinct from the other two subgenera by the almost total absence of PLA, thus indicating little or no contribution of PLA in the envenomation caused by Uraeus compared to Afronaja and Boulengerina. Furthermore, we report studies on the experimental testing of African cobra venoms and toxins against diseases including anti-cancer properties.
Topics: Animals; Elapid Venoms; Proteome; Antivenins; Naja; Phospholipases A2
PubMed: 38838860
DOI: 10.1016/j.toxicon.2024.107792