Economic Evaluations of Interventions for Snakebites: A Systematic Review

[Evaluation of snakebite management cost at Saint Jean de Dieu Hospital in Tanguiéta, Benin]

Introduction

Snakebite envenomations are a real public health problem in rural areas of sub-Saharan Africa, especially as the cost of management is often beyond the reach of the victims. The aim of our study was to evaluate the costs of treating snakebite envenomations at the Saint Jean de Dieu hospital in Tanguiéta, northern Benin, in a savannah area.

Methods

This was a descriptive cross-sectional study conducted over a three-month period from May 25 to August 25, 2023. Snakebite patients were followed from admission to hospital discharge. All care-related expenses incurred by patients and/or their families were accounted for on a daily basis.

Results

Fifty-seven patients were included. The median age (interquartile range) of the patients was 27 years (16-40), and the sex ratio was 1.6 (35 males and 22 females). In 81% of cases, the bites were associated with agricultural activities. Approximately 72% of the patients had sought traditional care before coming to the hospital. The median time from bite to admission was 7 hours (2-52) and the median hospital stay was 4 days (2-5). The median cost of care was €168 (154-242). It varied according to the severity of the bite: €31 for a dry bite (26-47); €179 for external bleeding (154-286). The only antivenom used was Inoserp™ PAN-AFRICA (Inosan Biopharma). Its average cost was €128 and was the main expense.

Conclusion

The cost of treating snakebite is high and dominated by the cost of antivenom. These economic constraints reinforce the vicious circle of poverty in an already vulnerable population. It is therefore important to find a financing mechanism for this treatment in the most exposed areas.

Epidemiology of Snake Bites Linked with the Antivenoms Production in Colombia 2008-2020: Produced Vials Do Not Meet the Needs

Introduction

Snakebite envenomation is a public health event of mandatory reporting in Colombia. It is considered a medical emergency in which the government must guarantee antivenom availability. We describe snakebite epidemiological figures in Colombia between 2008 and 2020 and correlate them with antivenom manufacturing figures to determine rate coverage and the need for antivenom.

Methods

We performed an ecological study based on secondary official figures from the National Health Institute, the National Institute for Surveillance of Medicines and Foods, the National Administrative Department of Statistics and the Ministry of Health and Social Protection. Absolute and relative frequencies were calculated with 95% confidence intervals, position measurements, dispersion and central tendency.

Results

Through our research, we revealed that in the last 13 years (2008-2020), there were an average of 4467 annual snakebite envenomation cases affecting all the departments in Colombia. Antioquia reported the highest number of snakebites with 647 (95% CI 588-706) cases per year. The population incidence per 100,000 inhabitants was 9.5; the highest rates were found in Vaupés at 116.1 and Guaviare at 79.24. During the last seven years (2014-2020) Colombia produced an average of 21,104 antivenom vials per year, while the annual demand for antivenom is estimated at 54,440 units needed to guarantee access.

Discussion

Colombia does not produce sufficient vials to cover their needs, and this is why only 74.4% of accidents (out of the 92% not classified as dry bites) were treated, and even 9.7% of the severe accidents did not receive the specific treatment (8% of the victims were classified as dry bites). Figures support the regular antivenom shortages declared by the Ministry of Health and Social Protection in the last 13 years (11 health emergency declarations). New efforts are needed to: 1) boost the production of GMP-based high-quality antivenom, that covers the national needs and is made availability, 2) a better estimation method to calculate the need for antivenom in Colombia, and 3) implementation of production-distribution chains guaranteeing access in remote communities.

Chronic health effects and cost of snakebite

The burden of disability among survivors and the socio-economic impact of snakebite have not been adequately researched. We reviewed original research articles, case reports and small case series relating to chronic physical, mental and psycho-social disability and economic burden of snakebite. Both physical and psychological health problems seem common in snakebite survivors and can lead to disability and loss of productivity. Chronic physical health effects, musculoskeletal disability being the commonest, can be largely attributed to limited and delayed access to optimal treatment of acute envenoming. The economic burden is considerable, and includes health system costs, out-of-pocket expenditure and opportunity costs, with regional variations. Health systems should be more responsive to needs and circumstances of bite victims, and a more holistic approach should be developed in the treatment of snakebite which incorporates the management of chronic health effects.

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Limited attention has been paid to chronic disability and the socio-economic impact of snakebite.

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Physical and psychological health problems occur in snakebite survivors leading to disability and loss of productivity.

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Chronic health effects can be largely attributed to limited and delayed access to optimal treatment of acute envenoming.

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Economic burden includes health system costs, out-of-pocket expenditure and opportunity costs.

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Health systems should be responsive to needs and circumstances of bite victims including care of chronic health effects.

Association of a Network of Immunologic Response and Clinical Features With the Functional Recovery From Crotalinae Snakebite Envenoming

Background

The immunologic pathways activated during snakebite envenoming (SBE) are poorly described, and their association with recovery is unclear. The immunologic response in SBE could inform a prognostic model to predict recovery. The purpose of this study was to develop pre- and post-antivenom prognostic models comprised of clinical features and immunologic cytokine data that are associated with recovery from SBE.

Materials and Methods

We performed a prospective cohort study in an academic medical center emergency department. We enrolled consecutive patients with Crotalinae SBE and obtained serum samples based on previously described criteria for the Surgical Critical Care Initiative (SC2i)(ClinicalTrials.gov Identifier: NCT02182180). We assessed a standard set of clinical variables and measured 35 unique cytokines using Luminex Cytokine 35-Plex Human Panel pre- and post-antivenom administration. The Patient-Specific Functional Scale (PSFS), a well-validated patient-reported outcome of functional recovery, was assessed at 0, 7, 14, 21 and 28 days and the area under the patient curve (PSFS AUPC) determined. We performed Bayesian Belief Network (BBN) modeling to represent relationships with a diagram composed of nodes and arcs. Each node represents a cytokine or clinical feature and each arc represents a joint-probability distribution (JPD).

Results

Twenty-eight SBE patients were enrolled. Preliminary results from 24 patients with clinical data, 9 patients with pre-antivenom and 11 patients with post-antivenom cytokine data are presented. The group was mostly female (82%) with a mean age of 38.1 (SD ± 9.8) years. In the pre-antivenom model, the variables most closely associated with the PSFS AUPC are predominantly clinical features. In the post-antivenom model, cytokines are more fully incorporated into the model. The variables most closely associated with the PSFS AUPC are age, antihistamines, white blood cell count (WBC), HGF, CCL5 and VEGF. The most influential variables are age, antihistamines and EGF. Both the pre- and post-antivenom models perform well with AUCs of 0.87 and 0.90 respectively.

Discussion

Pre- and post-antivenom networks of cytokines and clinical features were associated with functional recovery measured by the PSFS AUPC over 28 days. With additional data, we can identify prognostic models using immunologic and clinical variables to predict recovery from SBE.