Bites by exotic snakes reported to the UK National Poisons Information Service 2009-2020

Snakebite Management: The Need of Reassessment, International Relations, and Effective Economic Measures to Reduce the Considerable SBE Burden

The sole treatment for snakebite envenomation (SBE), the anti-snake venom (ASV), suffers from considerable drawbacks, including side effects and limited species specificity. Additionally, despite its existence for more than a century, uniform availability of good quality ASV does not yet exist. The present review describes the journey of a SBE victim and highlights the global crisis of SBE management. A detailed analysis of the current ASV market has also been presented along with the worldwide snake distribution. The current production of country specific licensed ASV throughout the globe along with their manufacturers has been examined at the snake species level. Furthermore, a detailed analysis of on-ground situation of SBE management in antivenom manufacturing countries has been done using the most recent literature. Additionally, the export and import of different ASVs have been discussed in terms of procurement policies of individual countries, their shortcomings, along with the possible solution at the species level. It is interesting to note that in most countries, the existence of ASV is really either neglected or overstated, implying that it is there but unsuitable for use, or that it is not present but can be obtained from other countries. This highlights the urgent need of significant reassessment and international collaborations not just for development and production, but also for procurement, distribution, availability, and awareness. A PROMISE (Practical ROutes for Managing Indigenous Snakebite Envenoming) approach has also been introduced, offering simple, economical, and easy to adopt steps to efficiently alleviate the worldwide SBE burden.

Neurotoxicology: a clinical systems-based review

Neurological disease caused by toxins is widespread but under-recognised. Despite increasing public interest and a growing number of novel potential neurotoxins, diagnosis of neurotoxic disease is often delayed or missed, resulting in poorer patient outcomes. This article discusses neurotoxic syndromes using a systems-based approach, focusing on environmental and occupational agents. We do not discuss recreational drugs, pharmaceutical agents or developmental neurotoxins in detail. We aim to provide neurologists with a working understanding of the scenarios in which a clinical presentation may be due to a neurotoxin and how to approach confirmation of the diagnosis.

African polyvalent antivenom can maintain pharmacological stability and ability to neutralise murine venom lethality for decades post-expiry: evidence for increasing antivenom shelf life to aid in alleviating chronic shortages

INTRODUCTION

Antivenom is a lifesaving medicine for treating snakebite envenoming, yet there has been a crisis in antivenom supply for many decades. Despite this, substantial quantities of antivenom stocks expire before use. This study has investigated whether expired antivenoms retain preclinical quality and efficacy, with the rationale that they could be used in emergency situations when in-date antivenom is unavailable.

METHODS

Using WHO guidelines and industry test requirements, we examined the in vitro stability and murine in vivo efficacy of eight batches of the sub-Saharan African antivenom, South African Institute for Medical Research polyvalent, that had expired at various times over a period of 30 years.

RESULTS

We demonstrate modest declines in immunochemical stability, with antivenoms older than 25 years having high levels of turbidity. In vitro preclinical analysis demonstrated all expired antivenoms retained immunological recognition of venom antigens and the ability to inhibit key toxin families. All expired antivenoms retained comparable in vivo preclinical efficacy in preventing the lethal effects of envenoming in mice versus three regionally and medically important venoms.

CONCLUSIONS

This study provides strong rationale for stakeholders, including manufacturers, regulators and health authorities, to explore the use of expired antivenom more broadly, to aid in alleviating critical shortages in antivenom supply in the short term and the extension of antivenom shelf life in the longer term.

Sudden death after a bite by a lowland swamp viper (Proatheris superciliaris) in Malawi: Dying of fright?

Proatheris superciliaris, the lowland swamp viper, has a limited distribution along lakeshores and rivers in Malawi, Southern Tanzania, and central Mozambique. Its venom is known to be procoagulant. Only five P. superciliaris bites have been reported, all inflicted by captive snakes, and none was fatal. Here we present a case of sudden death following a bite by Proatheris superciliaris in rural Malawi that cannot be attributed to envenoming. A healthy 32-year-old woman was planting rice in a flooded rice paddy field when she suddenly told her sister in a quiet voice that she had been bitten by a snake. She then collapsed face-upwards into the ankle-deep water. She remained motionless while her sister and uncle carried her out of the rice paddy onto dry land a few meters away. The victim did not regain consciousness. Her uncle heard one exhalation but no further breathing. The snake responsible was killed by a friend. Although the venom of this species can cause life-threatening coagulopathy, this woman's death occurred too rapidly to be attributable to envenoming. Only two explanations seem plausible: anaphylaxis, or vasovagal shock triggered by fear. In the present case, the victim died within minutes of the bite, closely observed by her anxious relatives, but showed no features of anaphylaxis. In Malawi, as in much of sub-Saharan Africa, many people are reportedly terrified of snakes, believing that bites by almost any species can cause rapid death. In this case, death occurred less than 2 min after a bite from Proatheris superciliaris. We believe that the cause of death was most likely a severe vasovagal attack, in response to the fear and pain of the snakebite that triggered vasodilatation, bradycardia, and hypotension leading to cardiac arrest.

Exotic (non-native) snakebite envenomation in Japan: A review of the literature between 2000 and 2022

A limited number of studies have investigated the clinical characteristics of snakebite envenomation by exotic (non-native) snakes in Japan. This study reviewed the literature to determine the status and risk of bites by exotic pet snakes in Japan. We reviewed reports of snakebite due to exotic snakes in Japan published between 2000 and 2022, excluding reports of bites by snakes native to Japan, such as Gloydius blomhoffii, Rhabdophis tigrinus, and Protobothrops flavoviridis. During the study period, 11 exotic snakebites were recorded, involving 11 species. The majority of those bitten (10/11 cases) were male, all cases were hand injuries, and there were no fatalities. The snakes responsible belonged to the Colubridae (4/11 cases), Viperidae (4/11 cases), and Elapidae (3/11 cases) families. Cases of envenomation by G. brevicaudus, Bungarus candidus, and Dendroaspis angusticeps were of particular interest. Ten of the eleven patients developed local cytotoxic signs, and three developed "compartment syndrome," in which the surgeons performed decompressive incisions. Two bites from elapid snakes and one from a viperid snake resulted in respiratory failure. Antivenom was given in two cases. Complications were observed, such as acute kidney injury, rhabdomyolysis, coagulopathy, and residual dysfunction of the affected finger. Emergency rooms should be prepared to manage patients who have been bitten by exotic snakes, even though the number of reported cases is not high in Japan. Initial stabilization of patients is crucial, before a definitive diagnosis is made, as with native snakebite envenomation. Finger bites are reported in most cases, which may result in functional impairment of the fingers. In order to collect more comprehensive patient data in Japan, a reporting system for all snakebite envenomations should be considered.

Mobile Zoos and Other Itinerant Animal Handling Events: Current Status and Recommendations for Future Policies

Mobile zoos are events in which non-domesticated (exotic) and domesticated species are transported to venues such as schools, hospitals, parties, and community centres, for the purposes of education, entertainment, or social and therapeutic assistance. We conducted literature searches and surveyed related government agencies regarding existing provisions within laws and policies, number of mobile zoos, and formal guidance issued concerning operation of such events in 74 countries or regions. We also examined governmental and non-governmental guidance standards for mobile zoos, as well as websites for mobile zoo operations, assessed promotional or educational materials for scientific accuracy, and recorded the diversity of species in use. We used the EMODE (Easy, Moderate, Difficult, or Extreme) algorithm, to evaluate identified species associated with mobile zoos for their suitability for keeping. We recorded 14 areas of concern regarding animal biology and public health and safety, and 8 areas of false and misleading content in promotional or educational materials. We identified at least 341 species used for mobile zoos. Mobile zoos are largely unregulated, unmonitored, and uncontrolled, and appear to be increasing. Issues regarding poor animal welfare, public health and safety, and education raise several serious concerns. Using the precautionary principle when empirical evidence was not available, we advise that exotic species should not be used for mobile zoos and similar itinerant events.

Early Adverse Reactions to Snake Antivenom: Poison Center Data Analysis

Antivenom is an essential treatment for snake envenomation; however, early adverse reactions (EARs) are major limitations to its use. We performed a retrospective cross-sectional study using Ramathibodi Poison Center data (January 2016 to December 2017) to clarify the incidence and severity of EARs following different F(ab’)2 antivenoms. Among 1006 envenomed patients, 684 (68%) received antivenom therapy with a total of 1157 doses, mostly green pit viper antivenom. The overall EAR incidence and rate were 22. 5% (154/684) and 15% (173/1157), respectively. The EAR rate following each type of antivenom was >10%, except for Russell’s viper antivenom (2.9%); the severe reaction rate was 2.6% (30/1157). Malayan pit viper bites caused a high incidence of EARs (37.8%) and the highest EAR rate (22.3%). Fifty-two cases developed anaphylaxis. All EARs occurred within 2 h after treatment initiation. No deaths were attributed to EARs. The duration of administration was significantly different between doses of antivenom that induced EARs and those that did not. In conclusion, all types and every dose of antivenom should be infused for 30−60 min. Preparation of resuscitation equipment and continuous clinical observation are crucial for at least 2 h after administration, and prompt treatment should be provided when EARs occur.