Availability, accessibility and use of antivenom for snakebite envenomation in Africa with proposed strategies to overcome the limitations

Inequalities in access to antivenom: An ethical issue in the management of snakebite envenoming

Snakebite envenoming is a high-priority neglected tropical disease and antivenom is the cornerstone of treatment. Antivenom is listed among essential medicines and its access must be considered as a human right. Despite resolutions from various international organizations including the WHO, antivenom remains unavailable, unaffordable, and sometimes not targeted against the specific snake involved. Also, despite an expanding global antivenom market, some manufacturers have stopped production due to a lack of profits. However, justice and equitable access to care according to medical needs are among the four pillars of medical ethics. Overall, snakebite envenoming is a typical example of social and ethnic inequity in medicine. It is imperative that this issue be addressed from an ethical standpoint and that government laboratories take the lead in antivenom production.

Preclinical testing of expired antivenoms and its uses in real-world experience: a systematic review

INTRODUCTION

Limited access to antivenoms is a global challenge in treating snakebite envenoming. In emergency situations where non-expired antivenoms are not readily available, expired antivenoms may be used to save lives with the risk of deteriorating quality, efficacy and safety. Therefore, we aimed to systematically review and summarise the sparse preclinical evidence of neutralising efficacy of expired antivenoms and real-world experience of using expired antivenoms in humans.

METHODS

We searched for articles published until 1 March 2023 in PubMed, Scopus, Web of Science and Embase. Studies demonstrating the preclinical studies evaluating expired antivenoms or studies describing the real-world experience of using expired antivenoms were included. Narrative synthesis was applied to summarise the evidence of expired antivenoms.

RESULTS

Fifteen studies were included. Ten were preclinical studies and five were real-world experiences of using expired antivenoms in humans. The expired duration of antivenoms in the included studies ranged from 2 months to 20 years. The quality of expired antivenoms was evaluated in one study, and they met the standard quality tests. Five studies demonstrated that the expired antivenoms' immunological concentration and venom-binding activity were comparable to non-expired ones but could gradually deteriorate after expiration. Studies consistently exhibited that expired antivenoms, compared with non-expired antivenoms, were effective when stored in proper storage conditions. The safety profile of using expired antivenoms was reported in two included studies. However, it was inconclusive due to limited information.

CONCLUSION

Even though the quality and efficacy of expired antivenoms are comparable to non-expired antivenoms in preclinical studies, the information is limited in terms of real-world experiences of using expired antivenoms and their safety. Therefore, the use of expired antivenoms may be generally inconclusive due to scarce data. Further investigations may be needed to support the extension of antivenoms' expiration date according to their potential efficacy after expiration.

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.

Current Status and Influencing Factors of Snakebite Diagnosis and Treatment Knowledge Among Medical Staff in China: A Cross-Sectional Study

Objectives: 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. Methods: 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. Results: 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. Conclusion: 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.

Compendium of medically important snakes, venom activity and clinical presentations in Ghana

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.