Lack of controlled studies on snakebite prevention: a rapid review

Globally, snakebites cause an estimated 80 000-140 000 deaths annually. While there are evidence-based recommendations for managing snakebite victims, recommendations on the prevention of snakebites are limited to expert opinions. We conducted a rapid review to summarise evidence from human studies with a control group on preventing snakebites. Searching PubMed, Web of Science, Scopus, CINAHL and EMBASE with inclusive search terms without language or time limits only yielded three eligible studies (one case control study and two prospective controlled clinical studies), highlighting a knowledge gap. Two studies in Nepal by the same group showed that health education of stakeholders and sleeping under a bednet can significantly reduce snakebite incidence (p<0.05), but these observations are not confirmed elsewhere, and because of the high risk of bias the certainty of evidence was low. The third study from Sri Lanka, which assessed if sleeping above ground would prevent snakebites, had inconclusive results. This demonstrates an urgent need for studies with a control group to guide evidence-based recommendations for snakebite prevention. Potential interventions tested can range from low-cost measures such as wearing appropriate footwear in resource-limited settings to testing the efficacy of chemical, biological (e.g. rodent control) or device-based methods and community-supported platforms tracking snakebite sightings with real-time geolocation data in highly resourced settings.

Knowledge and practices related to snakebite prevention, China: a cross-sectional study

Objective

To assess knowledge and practices related to snakebite prevention among Chinese residents.

Methods

By using a multistage random sampling approach augmented by snowball sampling, we surveyed residents from 10 provinces, one municipality and one autonomous region south of the Yangtze River Basin between May 2022 and February 2023. We supplemented the data with a national online survey. We used a χ2-test to identify differences in knowledge and behaviour across various demographic characteristics. We conducted multifactor logistic regression analyses to evaluate factors potentially influencing snakebite knowledge and practices.

Findings

We obtained 55 775 valid survey responses, 16 200 respondents from the face-to-face survey and 39 575 respondents from the online survey. Only 25.7% (14 325) respondents demonstrated adequate knowledge about snakebites whereas 25.6% (14 295) respondents knew basic first-aid practices or preventive behaviours. Age, marital status, educational attainment, occupation, type of residence and frequency of exposure to nature are significant independent variables affecting snakebite knowledge (P-values: < 0.05). On the other hand, gender, age, marital status, educational attainment, occupation and type of residence were significant independent variables affecting the behaviour of snakebite prevention and first aid (P-values: < 0.05).

Conclusion

There is a notable shortfall in knowledge, first aid and preventive behaviours among Chinese residents regarding snakebites. Misguided first aid practices can severely compromise the effectiveness of evidence-based therapeutic interventions. Consequently, improving health education concerning snakes and snakebites in this population is needed.

Stakeholder perspectives from 15 countries in Africa on barriers in snakebite envenoming research and the potential role of research hubs

Snakebite envenoming is a debilitating neglected tropical disease disproportionately affecting the rural poor in low and middle-income countries in the tropics and sub-tropics. Critical questions and gaps in public health and policy need to be addressed if major progress is to be made towards reducing the negative impact of snakebite, particularly in the World Health Organisation (WHO) Africa region. We engaged key stakeholders to identify barriers to evidence-based snakebite decision making and to explore how development of research and policy hubs could help to overcome these barriers. We conducted an electronic survey among 73 stakeholders from ministries of health, health facilities, academia and non-governmental organizations from 15 countries in the WHO Africa region. The primary barriers to snakebite research and subsequent policy translation were limited funds, lack of relevant data, and lack of interest from policy makers. Adequate funding commitment, strong political will, building expert networks and a demand for scientific evidence were all considered potential factors that could facilitate snakebite research. Participants rated availability of antivenoms, research skills training and disease surveillance as key research priorities. All participants indicated interest in the development of research and policy hubs and 78% indicated their organization would be willing to actively participate. In conclusion, our survey affirms that relevant stakeholders in the field of snakebite perceive research and policy hubs as a promising development, which could help overcome the barriers to pursuing the WHO goals and targets for reducing the burden of snakebite.

Empowering Health care Systems and Communities for Snakebite Envenoming Control in India

Snakebite envenoming (SBE) is a global health challenge, predominantly affecting economically disadvantaged regions. India contributes significantly to global snakebite mortality. Since 2013, the Indian Council of Medical Research (ICMR) has spearheaded efforts to combat SBE. A multi-sectoral engagement in the snakebite research projects and inputs from communities, traditional healers, and the health system have led to the creation of an Information Education and Communication (IEC) material suite, including management flowchart, information booklets, posters, and brochures, all available in local languages. These resources were broadly disseminated in high-burden regions in Maharashtra and Odisha, resulting in an approximately 10% increase in case reporting within a year. This holistic approach, engaging diverse stakeholders and addressing multiple facets of SBE, offers promise for alleviating the snakebite burden, not only in India but also in other low- and middle-income countries across South Asia, Africa, and South America, holding potential for broader positive global impact.

A Bibliometric Study on Global Snakebite Research Indexed in Web of Science

Objective: To conduct a bibliometric analysis of the global snakebite literature to provide a reference for the future development of snakebite research. Methods: The Web of Science citation analysis tools, VOSviewer and CiteSpace V were used to carry out the bibliometric analysis of the literature and generate visualization maps. Results: The number of publications has increased at a considerably accelerated rate in the past 8 years. Nine distinct cooperation clusters were formed between institutions and countries. Keyword clustering yielded nine well-structured clusters covering two major topics, i.e., snakebite envenoming and antivenom. Burstiness detection revealed eight keywords with strong emergence, including neglected tropical diseases, Elapidae, Viperidae, and Russell's viper, which have sustained popularity up to the present. Conclusion: Current research on snakebites has gradually garnered attention from the academic community. Cooperation papers between nations severely affected by snakebite and those with higher economic status received more attention. The continued exploration of therapeutic mechanisms, the development of antivenoms or alternative medicines, and primary prevention of snakebites to ensure the safety of populations in impoverished regions should be prioritized by international scholars. The epidemiological evidence and the timely translation of research findings should be valued by policymakers.

Experiences and practices of traditional healers on snakebite treatment and prevention in rural Malawi

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.

Community members and healthcare workers' priorities for the control and prevention of snakebite envenoming in Ghana

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.

Prevention and improvement of clinical management of snakebite in Southern Asian countries: A proposed road map

In the Southern Asian countries, snakebite takes a substantial toll in terms of human life, inflicts acute morbidity and long term disability both physical and psychological, and therefore represents a neglected socio-economic problem and severe health issue that requires immediate medical attention. The 'Big Four' venomous snakes, viz. Daboia russelii, Naja naja, Bungarus caeruleus and Echis carinatus, are prominent, medically important species and are the most dangerous snakes of this region; therefore, the commercial polyvalent antivenom (PAV) contains antibodies against the venoms of these snakes. However, envenomations by species other than the 'Big Four' snakes are grossly neglected, and PAV is only partially effective in neutralizing the venom of these snakes. Many issues confounding effective treatment of snakebite are discussed in this review, and these hurdles preventing successful treatment of snakebite must be addressed. However, in South Asian countries, the pre-hospital treatment and appropriate first aid are equally important to mitigate the problem of snakebite and therefore, these issues are also highlighted here. Further, this review suggests a roadmap and guidelines for the prevention of snakebite and improvement of hospital management of snakebite in these Southern Asian countries.

Control of snakebite envenoming: A mathematical modeling study

A mathematical model is designed to assess the impact of some interventional strategies for curtailing the burden of snakebite envenoming in a community. The model is fitted with real data set. Numerical simulations have shown that public health awareness of the susceptible individuals on snakebite preventive measures could reduce the number of envenoming and prevent deaths and disabilities in the population. The simulations further revealed that if at least fifty percent of snakebite envenoming patients receive early treatment with antivenom a substantial number of deaths will be averted. Furthermore, it is shown using optimal control that combining public health awareness and antivenom treatment averts the highest number of snakebite induced deaths and disability adjusted life years in the study area. To choose the best strategy amidst limited resources in the study area, cost effectiveness analysis in terms of incremental cost effectiveness ratio is performed. It has been established that the control efforts of combining public health awareness of the susceptible individuals and antivenom treatment for victims of snakebite envenoming is the most cost effective strategy. Approximately the sum of US$72,548 is needed to avert 117 deaths or 2,739 disability adjusted life years that are recorded within 21 months in the study area. Thus, the combination of these two control strategies is recommended.

Snakebite envenoming (SBE) is currently one of the life-threatening neglected diseases especially in developing countries. The fight against this menace requires multidisciplinary approach. Owing to significant number of deaths and disabilities recorded per year in West African savanna region, we developed a new mathematical model for SBE in order to gain more insights into the dynamics and control of SBE. It is clear that communities in northeast Nigeria do not have adequate health information on self-protection against SBE and the antivenom is almost scarce and unaffordable. Thus, we evaluated the cost-effectiveness and potential impact of both public health awareness campaign and treatment for SBE as interventional strategies against snakebite. We discovered that public health awareness is crucial in averting SBE, deaths and disabilities. Also, if at least 50% of SBE victims received treatment within 24 hours of bite, a significant number of deaths and disabilities will be prevented. Furthermore, the study revealed that the combination of public health awareness and treatment decreases the burden of the disease in terms of deaths and disability adjusted life years at a lesser cost as compared with implementing one of these interventions separately. These results can be used as a guide for planning SBE control policy in northeast Nigeria and beyond.

Utilising venom activity to infer dietary composition of the Kenyan horned viper (Bitis worthingtoni)

Bitis are well known for being some of the most commonly encountered and medically important snake species in all of Africa. While the majority of species possess potently anticoagulant venom, only B. worthingtoni is known to possess procoagulant venom. Although known to be the basal species within the genus, B. worthingtoni is an almost completely unstudied species with even basic dietary information lacking. This study investigated various aspects of the unique procoagulant effects of B. worthingtoni venom. Coagulation assays determined the primary procoagulant effect to be driven by Factor X activating snake venom metalloprotease toxins. In addition to acting upon the mammalian blood clotting cascade, B. worthingtoni venom was also shown to clot amphibian plasma. As previous studies have shown differences in clotting factors between amphibian and mammalian plasmas, individual enzymes in snake venoms acting on plasma clotting factors can be taxon-selective. As venoms evolve under purifying selection pressures, this suggests that the procoagulant snake venom metalloprotease toxins present in B. worthingtoni have likely been retained from a recent common ancestor shared with the related amphibian-feeding Proatheris superciliaris, and that both amphibians and mammals represent a substantial proportion of B. worthingtoni current diet. Thus, taxon-specific actions of venoms may have utility in inferring dietary composition for rare or difficult to study species. An important caveat is that to validate this hypothesis field studies investigating the dietary ecology of B. worthingtoni must be conducted, as well as further investigations of its venom composition to reconstruct the molecular evolutionary history of the toxins present.

Global Availability of Antivenoms: The Relevance of Public Manufacturing Laboratories

Snakebite envenoming is a serious global public health problem, and international initiatives, under the coordination of the World Health Organization and its regional offices, are being developed to reduce the impact of this neglected tropical disease. The global availability of safe and effective antivenoms is one of the key aspects in this global strategy. This review discusses the role of public antivenom manufacturing laboratories for ensuring the supply of antivenoms. The difficulties faced by public laboratories are discussed, together with some tasks that need to be implemented for strengthening them. In addition, the concept of ‘redundancy’ in the supply of antivenoms is emphasized, as a way to cope with the risks associated with the provision of antivenoms by few manufacturers. In general, the public sector should play a leading role, in antivenom availability and other aspects as well, within the global struggle to reduce the mortality and morbidity caused by snakebite envenoming.

Stepping into a dangerous quagmire: Macroecological determinants of Bothrops envenomings, Brazilian Amazon

Despite significant and successful efforts in Brazil regarding snakebites in the areas of research, antivenom manufacture and quality control, training of health professionals in the diagnosis and clinical management of bites, little is known about determinants of snakebites incidence in order to further plan interventions to reduce the impact of this medical condition. Understanding the complexity of ecological interactions in a geographical region is important for prediction, prevention and control measures of snakebites. This investigation aims to describe spatial distribution and identify environmental determinants of human envenoming by lancehead pit vipers (Bothrops genus), in the Brazilian Amazon. Aggregated data by the municipality was used to analyze the spatial distribution of Bothrops bites cases and its relationship with geographic and environmental factors. Eight geo-environmental factors were included in the analysis as independent variables: (1) tree canopy loss increase; (2) area with vegetation cover; (3) area covered by water bodies; (4) altitude; (5) precipitation; (6) air relative humidity; (7) soil moisture; and (8) air temperature. Human envenoming by lancehead pit vipers (Bothrops genus) in the Amazon region is more incident in lowlands [Adjusted regression coefficient [ARC] -0.0007 (IC95%: -0.001; -0.0006), p<0.0001], with high preserved original vegetation cover [ARC 0.0065 (IC95%: 0.0071; 0.0060), p<0.0001], with heaviest rainfall [ARC 0.0001 (IC95%: 0.00009; 0.0001), p<0.0001] and higher air relative humidity [ARC 0.0082 (IC95%: 0.0108; 0.0056), p<0.0001]. This association is interpreted as the result of the higher prey availability and further abundance of pit vipers in such landscapes.

Vulnerability to snakebite envenoming: a global mapping of hotspots

BACKGROUND

Snakebite envenoming is a frequently overlooked cause of mortality and morbidity. Data for snake ecology and existing snakebite interventions are scarce, limiting accurate burden estimation initiatives. Low global awareness stunts new interventions, adequate health resources, and available health care. Therefore, we aimed to synthesise currently available data to identify the most vulnerable populations at risk of snakebite, and where additional data to manage this global problem are needed.

METHODS

We assembled a list of snake species using WHO guidelines. Where relevant, we obtained expert opinion range (EOR) maps from WHO or the Clinical Toxinology Resources. We also obtained occurrence data for each snake species from a variety of websites, such as VertNet and iNaturalist, using the spocc R package (version 0.7.0). We removed duplicate occurrence data and categorised snakes into three groups: group A (no available EOR map or species occurrence records), group B (EOR map but <5 species occurrence records), and group C (EOR map and ≥5 species occurrence records). For group C species, we did a multivariate environmental similarity analysis using the 2008 WHO EOR maps and newly available evidence. Using these data and the EOR maps, we produced contemporary range maps for medically important venomous snake species at a 5 × 5 km resolution. We subsequently triangulated these data with three health system metrics (antivenom availability, accessibility to urban centres, and the Healthcare Access and Quality [HAQ] Index) to identify the populations most vulnerable to snakebite morbidity and mortality.

FINDINGS

We provide a map showing the ranges of 278 snake species globally. Although about 6·85 billion people worldwide live within range of areas inhabited by snakes, about 146·70 million live within remote areas lacking quality health-care provisioning. Comparing opposite ends of the HAQ Index, 272·91 million individuals (65·25%) of the population within the lowest decile are at risk of exposure to any snake for which no effective therapy exists compared with 519·46 million individuals (27·79%) within the highest HAQ Index decile, showing a disproportionate coverage in reported antivenom availability. Antivenoms were available for 119 (43%) of 278 snake species evaluated by WHO, while globally 750·19 million (10·95%) of those living within snake ranges live more than 1 h from population centres. In total, we identify about 92·66 million people living within these vulnerable geographies, including many sub-Saharan countries, Indonesia, and other parts of southeast Asia.

INTERPRETATION

Identifying exact populations vulnerable to the most severe outcomes of snakebite envenoming at a subnational level is important for prioritising new data collection and collation, reinforcing envenoming treatment, existing health-care systems, and deploying currently available and future interventions. These maps can guide future research efforts on snakebite envenoming from both ecological and public health perspectives and better target future estimates of the burden of this neglected tropical disease.

FUNDING

Bill & Melinda Gates Foundation.

Variability in venom composition of European viper subspecies limits the cross-effectiveness of antivenoms

Medically relevant cases of snakebite in Europe are predominately caused by European vipers of the genus Vipera. Systemic envenoming by European vipers can cause severe pathology in humans and different clinical manifestations are associated with different members of this genus. The most representative vipers in Europe are V. aspis and V. berus and neurological symptoms have been reported in humans envenomed by the former but not by the latter species. In this study we determined the toxicological profile of V. aspis and V. berus venoms in vivo in mice and we tested the effectiveness of two antivenoms, commonly used as antidotes, in counteracting the specific activities of the two venoms. We found that V. aspis, but not V. berus, is neurotoxic and that this effect is due to the degeneration of peripheral nerve terminals at the NMJ and is not neutralized by the two tested antisera. Differently, V. berus causes a haemorrhagic effect, which is efficiently contrasted by the same antivenoms. These results indicate that the effectiveness of different antisera is strongly influenced by the variable composition of the venoms and reinforce the arguments supporting the use polyvalent antivenoms.

Mortality due to snakebite and other venomous animals in the Indian state of Bihar: Findings from a representative mortality study

Background

Animal bites and stings contribute significantly to mortality in certain parts of the world. India accounts for the highest number of snakebites and related mortality globally. We report on mortality due to bite or sting of a venomous animal from a population-based study in the Indian state of Bihar which estimated the causes of death using verbal autopsy.

Methodology/principal findings

Interviews were conducted for all deaths that occurred from January 2012 to March 2014 in 109,689 households (87.1% participation) covering 627,658 population in 1,017 clusters representative of the state using the Population Health Metrics Research Consortium shortened verbal autopsy questionnaire. Cause of death was assigned using the SmartVA automated algorithm. The annualized mortality rate per 100,000 population due to snakebite, scorpion sting and other animals adjusted for age, sex and urban-rural population distribution of the state; and detailed contextual information on snakebites are reported. Deaths due to bite/sting of a venomous animal accounted for 10.7% of all deaths due to unintentional injuries, with an adjusted mortality rate of 6.2 (95% CI 6.0–6.3) per 100,000 population. The adjusted snakebite mortality rate was 4.4 (95% CI 4.3–4.6) which was significantly higher in the rural areas (4.8, 95% CI 4.7–5.0) and in females (5.5, 95% CI 5.3–5.7). Snakebites accounted for 7.6% of all unintentional injury deaths across all ages but for 33.3% of the deaths in 10–14 years age group. A similar proportion of snakebite deaths occurred while sleeping (30.2%), playing (30.2%) and during field/outdoor activities (27.9%). In these cases, 8.2% people were already dead when found, 34.7% had died before treatment could be provided, and 28 (57.1%) had died post treatment among whom 46.4% had sought treatment at a health facility, 25% with a traditional healer, and the rest from both. Death before reaching a health provider, non-availability of medicines or doctor, referral patterns, and sex-differentials in the context of snakebite deaths are reported. None of the verbatim specifically mentioned anti-venom being used for treatment. The adjusted mortality rate for scorpion sting was 0.9 (95% CI 0.8–0.9).

Conclusions

The findings from this large representative sample documents the magnitude of snakebite mortality in Bihar and highlight the circumstances surrounding the snakebite events that could facilitate prevention and intervention opportunities.

Bites, stings, and rigors: clinical considerations in African operations

The natural health threats in Africa pose daunting clinical challenges for any provider, as evidenced by the current Ebola epidemic in West Africa, but the threat is multiplied for the Special Operations provider on the continent who faces these challenges with limited resources and the tyranny of distance. The majority of operationally significant health risks can be mitigated by strict adherence to a comprehensive force health protection plan. The simplest, yet most effective, technique for preventing mosquito-borne diseases is the prevention of mosquito bites with repellent, bed nets, and appropriate clothing in addition to chemoprophylaxis. Some of the more likely or lethal infectious diseases encountered on the continent include malaria, Chikungunya, dengue, human immunodeficiency virus, and Ebola. Venomous snakes pose a particular challenge since the treatment can be as deadly as the injury. Providers supporting African operations should educate themselves on the clinical characteristics of possible envenomations in their area while promoting snake avoidance as the primary mitigation measure. To succeed in Africa, the Special Operations provider must consider how to meet these challenges in an environment where there may not be reliable evacuation, hospitalization, or logistics channels.

Effectiveness of rapid transport of victims and community health education on snake bite fatalities in rural Nepal

Snake bite is a major public problem in the rural tropics. In southern Nepal, most deaths caused by neurotoxic envenomation occur in the village or during transport to health centers. The effectiveness of victims' transport by motorcycle volunteers to a specialized treatment center, combined with community health education, was assessed in a non-randomized, single-arm, before-after study conducted in four villages (population = 62,127). The case-fatality rate of snake bite decreased from 10.5% in the pre-intervention period to 0.5% during the intervention (relative risk reduction = 0.949, 95% confidence interval = 0.695-0.999). The snake bite incidence decreased from 502 bites/100,000 population to 315 bites/100,000 population in the four villages (relative risk reduction = 0.373, 95% confidence interval = 0.245-0.48), but it remained constant in other villages. Simple educational messages and promotion of immediate and rapid transport of victims to a treatment center decreased the mortality rate and incidence of snake bite in southeastern Nepal. The impact of similar interventions should be assessed elsewhere.

[Hiking and useful advices to patients (part 1)]

The attraction of walking as a pastime has grown enormously in Switzerland over the past few years. Synonym of health and well-being, this activity carries some risks which more and more patients are questioning; answering these questions is not always obvious, so we wanted to tackle the subject. Risks linked to certain animals will be covered. One of these risks is insect stings, particularly wasps and bees. This is a major problem which affects the whole population and more seriously those who are allergic, accounting for around 5% of the population. Another problem: snake bites. In Switzerland, there are about 20-25 bites each year. Poisoning from these can be divided into two categories: local or systemic. The effects are multiple and diverse, ranging from renal failure to discrasia to hypovolemic shock. Pre-hospitalisation measures are of paramount importance in the treatment.

Snakebites in adults from the Diyarbakir region in southeast Turkey

BACKGROUND

Snake venom poisoning is a medical emergency requiring immediate attention. Bites from poisonous Turkish snakes can lead to local tissue damage and systemic symptoms. The Vipera ammodytes species accounts for the majority of envenomation in southeast Turkey.

METHODS

The demographic and epidemiological characteristics, clinical symptoms and signs, laboratory findings, treatment, and outcome of 79 consecutive victims of V. ammodytes poisoning admitted to our hospital from 2003 to 2005 were reviewed and analyzed prospectively.

RESULTS

The most common symptoms and signs included fang marks (100%), pain (100%), swelling (83.5%), ecchymosis (92.4%), tachycardia (24.1%), fainting or dizziness (14.5%), fever (19.0%), enlargement of regional lymph nodes (43.0%), nausea (70.9%), hypotension (21.5%), vomiting (36.7%), and dyspnea (3.2%). The main complications were thrombophlebitis, reduced range of motion, local hemorrhagic blister formation, bleeding from skin, rhabdomyolysis, reduced sensation, acute renal failure, necrosis with tissue loss, digit amputation, carpal tunnel syndrome, and compartment syndrome.

CONCLUSION

A V. Ammodytes bite is a potentially serious event that requires immediate hospital care. Nevertheless, the majority of victims can be treated successfully with conservative methods. No deaths occurred in our series.

Snake bite

Snake bite is a common and frequently devastating environmental and occupational disease, especially in rural areas of tropical developing countries. Its public health importance has been largely ignored by medical science. Snake venoms are rich in protein and peptide toxins that have specificity for a wide range of tissue receptors, making them clinically challenging and scientifically fascinating, especially for drug design. Although the full burden of human suffering attributable to snake bite remains obscure, hundreds of thousands of people are known to be envenomed and tens of thousands are killed or maimed by snakes every year. Preventive efforts should be aimed towards education of affected communities to use proper footwear and to reduce the risk of contact with snakes to a minimum through understanding of snakes' behaviour. To treat envenoming, the production and clinical use of antivenom must be improved. Increased collaboration between clinicians, epidemiologists, and laboratory toxinologists should enhance the understanding and treatment of envenoming.

New Zealand's venomous creatures

AIM

New Zealand is home to a small number of venomous creatures. The purpose of this review is to educate and update healthcare professionals on the management of envenoming from these creatures.

METHODS

An extensive literature review was performed by systematically searching OVID MEDLINE and ISI Web of Science. In addition, further information was obtained from book chapters, relevant news reports, and web material.

RESULTS

The signs and symptoms resulting from envenoming of clinically significant venomous creatures found in New Zealand are discussed. Definitive medical treatment recommendations are made.

CONCLUSION

Encounters with New Zealand's few venomous creatures, while rarely fatal, can cause significant morbidity. Effective management can be achieved by informed health professionals having regard to the principles outlined in this review.

Venomous snakebite in mountainous terrain: prevention and management

The prevention and management of venomous snakebite in the world's mountains present unique challenges. This paper presents a series of practical, clinically sound recommendations for management of venomous snakebite in a mountain environment. The authors performed an extensive review of current literature using search engines and manual searches. They then fused the abundant knowledge of snakebite with the realities of remote first aid and mountain rescue to develop recommendations. A summary is provided of the world's most troublesome mountain snakes and the mechanisms of toxicity from their bites. Preventive measures are described. Expected symptoms and signs are reviewed in lay and medical terms. A review of currently recommended first-aid measures and advanced medical management for physicians, paramedics, and other clinicians is included. Venomous snakebites in mountainous environments present unique challenges for management. This paper offers practical recommendations for managing such cases and summarizes the approach to first aid and advanced management in 2 algorithms.

Trends in Fatal Snakebites in Venezuela, 1995–2002☆

OBJECTIVE

There have been few studies evaluating snakebite mortality in Venezuela and South America. In this study we evaluate trends in fatal snakebites occurring in Venezuela between 1995 and 2002.

METHODS

Epidemiological data for this study were retrieved from the records of the Ministry of Health of Venezuela. Using these data, we analyzed the impact of snakebites in Venezuela during the study period.

RESULTS

During the study period, there were 266 reports of death due to snakebite; 79.7% were males, and 20.3% were females (P < .01). Annual mean deaths numbered 33 per year. Of total deaths, 24.1% occurred in victims 55-70 years old. Deaths in young children (<5 years old) accounted for 7.1% of the total. Mortality rate by age showed an age-dependent rate, with higher rates in older ages (P = .038).

CONCLUSION

Snake envenomations are an important cause of injury and deaths in Venezuela as in many American countries. Surveillance of envenomations is essential for establishing guidelines, planning therapeutic supplies, and training medical staff on snakebite treatment, as well as assessing risk zones for travelers.

Protection against snake bites by sleeping under a bed net in southeastern Nepal

Snake bites in persons while they are asleep indoors are associated with a high risk of fatal outcome in southeastern Nepal. The preventive impact of sleeping under a bed net was assessed in four villages in a case-control study. A case was defined as a person with a history of snake bite that occurred indoors while asleep. Cases were matched with controls by village, type of household, sex, and age category. Of the 11,176 households visited, 56 cases, including 13 (23%) with a fatal outcome and 56 controls were included in the analysis. Sleeping under a bed net was a strong protective factor (odds ratio = 0.02, 95% confidence interval = 0.007-0.07, P < 0.0001), whereas the place of sleeping in the household and the use of a cot were not associated with the risk of snake bite. These findings provide further support for use of bed nets in this region.

Rattlesnake envenomation

Snake envenomation has been widely reported throughout the human and veterinary literature. The effects of venom include coagulation disorders, neurotoxicity, and tissue effects, such as local swelling and necrosis. Significant progress has been made in understanding the pathophysiology of envenomation, leading to changes in treatment protocols. Recent developments include the production of a new antivenin and a canine rattlesnake vaccine.

[Snakes, scorpions and other poisonous creatures: prophylaxis and emergency medicine]

Most cases of poisoning by animals are caused by snakes, spiders or scorpions. In addition to"first aid" such as calming the victim and immobilization of the bitten limb, other measures include monitoring vital functions and rapid transportation to hospital as dictated by the symptoms presenting, and, where indicated, injection of an antiserum (identification of the animal concerned). On no account should the bite wound be cut or attempts made to suck out the venom. While the sting of a scorpion or a spider bite often do not lead to severe complications in adults, a brush with a poisonous snake may be much more serious.

Snakebite

The five families of poisonous snakes are: Viperidae, elapidae, colubridae, hydrophidae, atractaspididae. The commonly seen snakes in India are saw scaled viper, Russell's viper, common cobri and common crait. The venom of a single snake contains all the toxins. The venom of viperidae is haemotoxic. It may complicate with acute renal failure if left untreated. The venom of elapidae is neurotoxic. Management consists in two parts-general and specific. Supportive treatment is done with the use of antibiotics and tetanus immunoglobulin/toxoid. Specific therapy for viper bite is elaborated in this article. Elapid bite and hydrophidae bites are also discussed. Prevention of snakebite is done with avoidance of contact with a snake by using protective knee length footwear and thick gloves. Venom toxoids are used for secondary prevention among the farmers of Japan.

Most lay people can correctly identify indigenous venomous snakes

We attempted to determine how accurately members of the public can identify venomous snakes. Six different snakes indigenous to southern California were displayed in cages for 265 people to view at a street fair. These included 4 nonvenomous snakes and 2 venomous snakes. People were asked whether the snake was venomous and the name of the snake, if they knew it. Overall, people recognized whether a snake was venomous or nonvenomous 81% of the time. They were most accurate at identifying rattlesnakes as being venomous (95%) but incorrectly identified nonvenomous snakes as being venomous 25% of the time. Men were more accurate than women, and adults were more accurate than children. Subjects were less well able to identify the exact species of snakes. The results suggest that there may be no need to capture, kill, or bring a snake to the hospital for identification, at least in this geographic area.

Protective immunity against alpha-cobratoxin following a single administration of a genetic vaccine encoding a non-toxic cobratoxin variant

Venomous snakebites result in almost 125,000 deaths per year worldwide. We present a new paradigm for the development of vaccines to protect against snakebite, using knowledge of the structure and action of specific toxins combined with a gene-based strategy to deliver a toxin gene modified to render it non-toxic while maintaining its three-dimensional structure and hence its ability to function as an immunogen. As a model for this approach, we developed a genetic vaccine to protect against alpha-cobratoxin (CTX), a potent, post-synaptic neurotoxin that is the major toxic component of the venom of Naja kaouthia, the monocellate cobra. To develop the vaccine, substitutions in the CTX cDNA were introduced at two residues critical for binding to the nicotinic acetylcholine receptor (Asp27 to Arg, Arg33 to Gly). The mutated CTX expression cassette was delivered in the context of a replication deficient adenovirus vector (AdmCTX). To assess whether expression of the mutated CTX in vivo leads to the development of protective immunity, BALB/c mice were challenged by IV administration of 2 microg of alpha-cobratoxin protein 21 or 63 days after administration of AdmCTX or Ad- Null (as a control; both, 10(9) particle units). Animals receiving AdmCTX but no alpha-cobratoxin challenge suffered no ill effects, but > or =80% of naive animals or those receiving the AdNull control vector died within 10 min from the alpha-cobratoxin challenge. In contrast, 100% of animals receiving a single dose of AdmCTX 21 or 63 days prior to alpha-cobratoxin challenge survived. The data demonstrates that an adenovirus-based vaccine can be developed to protect against lethal challenge with a potent snake venom. The effectiveness of this approach might serve as a basis to consider the development of a global public health program to protect those at risk for death by snakebite.

Venomous snakes of Saudi Arabia and the Middle East: a keynote for travellers

Geographically Saudi Arabia and the Middle East include Asian Turkey, Syria, Lebanon, Jordan, Israel, Palestine, the Arabian Peninsula, Iraq, Iran and the previous Southern Asiatic Soviet Republics. The snake fauna contains species in common with northern Africa, Europe and central Asia and towards the east there is infiltration of species characteristic of tropical Asia. A classification of the venomous snakes of this area together with their distribution in the different countries is presented. The epidemiology of snake bites, pathophysiology of toxicity and the clinical features of envenoming by the different species of snakes are discussed. Management of snake bite victims including first aid, treatment at the hospital, clues from signs and symptoms that can help in the identification of the causative snake and antivenom treatment is stressed. Traditional manipulations like local incision and suction, use of caustics, oxidizing agents and cryotherapy and the injudicious use of tourniquets are evaluated and criticized. Finally the preventive control of snake bites for travellers in areas infested with venomous snakes is presented and discussed.

[Dangerous animals]

As travellers seek ever more exotic destinations they are more likely to encounter dangerous animals. Compared to risks such as AIDS, traffic accidents and malaria, the risk is not so great; many travellers are, however, concerned about this and those who give pre-travel vaccines and advice should know something about it. This article is mainly based on medical and zoological textbooks. Venomous stings and bites may be prevented by adequate clothing and by keeping safe distance to the animals. Listening to those who live in the area is of course important. Travellers should not carry antisera with them, but antisera should be available at local hospitals. It should be borne in mind that plant eaters cause just as many deaths as large predators. In some cases it is necessary to carry a sufficiently powerful firearm.

Venomous snakebites in the United States: management review and update

Venomous snakebites, although uncommon, are a potentially deadly emergency in the United States. Rattlesnakes cause most snakebites and related fatalities. Venomous snakes in the United States can be classified as having hemotoxic or neurotoxic venom. Patients with venomous snakebites present with signs and symptoms ranging from fang marks, with or without local pain and swelling, to life-threatening coagulopathy, renal failure, and shock. First-aid techniques such as arterial tourniquets, application of ice, and wound incisions are ineffective and can be harmful; however, suction with a venom extractor within the first five minutes after the bite may be useful. Conservative measures, such as immobilization and lymphatic constriction bands, are now advocated until emergency care can be administered. Patients with snakebites should undergo a comprehensive work-up to look for possible hematologic, neurologic, renal, and cardiovascular abnormalities. Equine-derived antivenin is considered the standard of care; however, a promising new treatment is sheep-derived antigen binding fragment ovine (CroFab), which is much less allergenic. Although there is no universal grading system for snakebites, a I through IV grading scale is clinically useful as a guide to antivenin administration. Surgical intervention with fasciotomy is now reserved for rare cases. Snakebite prevention should be taught to patients.

Newer antidotal therapies

Although the availability of an antidote for a toxic agent does not take away the primary responsibility of the clinician to manage the patient's clinical signs, the use of antidotes in appropriate situations can result in a more rapid recovery with potentially fewer long-term complications. Recent advances in pharmacology and molecular biology have resulted in the development of new and safer antidotal therapies for the management of toxicosis. The progress in immunotoxicotherapy over the last two decades continues and may ultimately lead to an era when the clinical toxicologist has a vast array of antibody fragments available for use with specific toxic agents. Development of specific pharmacologic antagonists for other agents should also enable the clinician to more reliably manage toxicoses. In spite of all these potential advances, the management of most toxicoses still relies on the application of sound veterinary medical principles.

Unusual neurotoxic envenomations by Vipera aspis aspis snakes in France

Vipera aspis aspis (V.a.a.) is the most dangerous poisonous snake in South-Eastern France. The clinical symptoms observed after V.a.a. envenomations involve mostly local signs (pain, edema) associated in the more severe cases with systemic symptoms (gastro-intestinal and cardiovascular manifestations). Since 1992, several unusual cases of moderate and severe 'neurotoxic' envenomations by V.a.a. snakes have been reported in a very localized area in South-Eastern France. Most of the human patients mainly suffered neurological signs owing to cephalic muscle paralysis. Drowsiness and dyspnea were observed for the most severe cases. Envenomed animals suffered respiratory distress and paralysis. The local signs were never as severe as observed after envenomations by vipers in other French regions. Human patients with moderate or severe clinical features received two intravenous injections of Viperfav antivenom, the first dose inducing the decrease of the neurological signs and the second reducing significantly the edema. Neurotoxic components immunologically cross-reacting with toxins from V. ammodytes ammodytes venom from Eastern Europe were detected in the blood of all patients suffering neurological symptoms after a V.a.a. bite. The protective efficacy of various antivenoms was evaluated in mice. The existence of geographical variations in the composition of V.a.a. venom emphasizes on the use of polyvalent antivenom in the treatment of viper envenomations in France.

[Poisonous snake bites: prevention--first aid--clinical management]

Envenomation due to terrestrial snakes is a rarity in travellers and tourists and can be readily controlled by preventive measures. It is a widely underestimated health problem of the rural population in tropical and subtropical countries, however. Prevention, First Aid, diagnostic procedures, symptomatic and specific (antivenom) treatment regimens of envenomation due to terrestrial snakes are presented.