Health and economic burden estimates of snakebite management upon health facilities in three regions of southern Burkina Faso

Development of a Biosensor to Detect Venom of Malayan Krait (Bungarus candidus)

Malayan krait (Bungarus candidus) envenoming is a cause of significant morbidity and mortality in many Southeast Asian countries. If intubation and specific antivenom administration are delayed, the most significant life-threatening outcome may be the inhibition of neuromuscular transmission and subsequent respiratory failure. It is recommended that krait-envenomed victims without indications of neurotoxicity, e.g., skeletal muscle weakness or ptosis, immediately receive 10 vials of antivenom. However, the administration of excess antivenom may lead to hypersensitivity or serum sickness. Therefore, monitoring venom concentrations in patients could be used as an indicator for snake antivenom treatment. In this study, we aimed to develop a screen-printed gold electrode (SPGE) biosensor to detect B. candidus venom in experimentally envenomed rats. The gold electrodes were coated with monovalent Malayan krait IgG antivenom and used as venom detection biosensors. Electrochemical impedance spectrometry (EIS) and square wave voltammetry (SWV) measurements were performed to detect the electrical characterization between B. candidus venom and monovalent IgG antivenom in the biosensor. The EIS measurements showed increases in charge transfer resistance (Rct) following IgG immobilization and incubation with B. candidus venom solution (0.1-0.4 mg/mL); thus, the antibody was immobilized on the electrode surface and venom was successfully detected. The lowest current signal was detected by SWV measurement in rat plasma collected 30 min following B. candidus experimental envenoming, indicating the highest level of venom concentration in blood circulation (4.3 ± 0.7 µg/mL). The present study demonstrates the ability of the SPGE biosensor to detect B. candidus venom in plasma from experimentally envenomed rats. The technology obtained in this work may be developed as a detection tool for use along with the standard treatment of Malayan krait envenoming.

"I sold my towel and shoes to pay the traditional healer": Care-seeking costs and productivity losses among snakebite victims in Eastern Province, Rwanda

Snakebite envenomation (SBE) is endemic to sub-Saharan Africa and generally over-represented in rural, remote, and impoverished agricultural communities. While poverty is an established risk factor, little research has been done to investigate the economic consequences of SBE. This cross-sectional, quantitative study aimed to measure out-of-pocket spending and lost income when a household member was bitten by a snake. In 2020, 732 snakebite survivors from Eastern Province (Rwanda) agreed to complete a survey administered by telephone. The survey focused on participant demographics, income, direct medical and non-medical costs, care-seeking decisions, and lost work during convalescence. Our results suggested that patients incurred the highest mean expenses when they sought care from hospitals (11 307 RWF or 12 USD) or traditional healers (5 836 RWF or 6 USD) but that the highest maximum cost was incurred from traditional healers (300 000 RWF or 313 USD). Across all victims, the total amount paid to traditional healers (3.4 million RWF or 3 537 USD) was 4.7 times higher than all other care providers combined. On average, families lost 111 814 RWF (117 USD) per snakebite in direct treatment costs and indirect productivity losses. Many victims sought care from traditional healers despite being eligible for free medical care. Altogether, this study serves as a reminder of the serious physical and financial consequences associated with SBE and provides justification for new investments into SBE prevention and care.

Real life condition evaluation of Inoserp PAN-AFRICA antivenom effectiveness in Cameroon

BACKGROUND

Snakebites is a serious public health issue but remains a neglected tropical disease. Data on antivenom effectiveness are urgently needed in Africa. We assessed effectiveness of Inoserp PAN-AFRICA (IPA), the recommended antivenom available in Cameroon.

METHODOLOGY/PRINCIPAL FINDINGS

We enrolled 447 patients presenting with snakebite in 14 health facilities across Cameroon. At presentation, cytotoxicity, coagulation troubles and neurotoxicity were graded. We administered two to four vials of antivenom to patients based on hemotoxic or neurotoxic signs. We renewed antivenom administration to patients with persistence of bleedings or neurotoxicity 2 hours after each injection. We defined early improvement as a reduction of the grade of envenomation symptoms 2 hours after first injection. Medium-term effectiveness was investigated looking at disappearance of symptoms during hospitalization. After hospital discharge, a home visit was planned to assess long-term outcomes. Between October 2019 and May 2021, we enrolled 447 (93.7%), including 72% from the savannah regions. The median [IQR] age was 25 [14-40]. Envenomation was diagnosed in 369 (82.6%) participants. The antivenom was administered to 356 patients (96.5%) of whom 256 (71.9%) received one administration. Among these patients, cytotoxic symptoms were observed in 336 (94.4%) participants, coagulation disorders in 234 (65.7%) participants and neurotoxicity in 23 (6.5%) participants. Two hours after the first administration of antivenom, we observed a decrease in coagulation disorders or neurotoxicity in 75.2% and 39.1% of patients, respectively. Complete cessation of bleedings and neurotoxicity occurred in 96% and 93% of patients within 24 hours, respectively. Sequelae have been observed in 9 (3%) patients at the home visit 15 days after hospital admission and 11 (3%) died including one before antivenom injection.

CONCLUSIONS/SIGNIFICANCE

We confirmed good effectiveness of the IPA and highlighted the rapid improvement in bleeding or neurotoxicity after the first administration. Sequential administrations of low doses of antivenom, rigorously assessed at short intervals for an eventual renewal, can preserve patient safety and save antivenom.

TRIAL REGISTRATION

NCT03326492.

Estimating economic and disease burden of snakebite in ASEAN countries using a decision analytic model

Background

Understanding the burden of snakebite is crucial for developing evidence-informed strategies to pursue the goal set by the World Health Organization to halve morbidity and mortality of snakebite by 2030. However, there was no such information in the Association of Southeast Asian Nations (ASEAN) countries.

Methodology

A decision analytic model was developed to estimate annual burden of snakebite in seven countries, including Malaysia, Thailand, Indonesia, Philippines, Vietnam, Lao PDR, and Myanmar. Country-specific input parameters were sought from published literature, country’s Ministry of Health, local data, and expert opinion. Economic burden was estimated from the societal perspective. Costs were expressed in 2019 US Dollars (USD). Disease burden was estimated as disability-adjusted life years (DALYs). Probabilistic sensitivity analysis was performed to estimate a 95% credible interval (CrI).

Principal findings

We estimated that annually there were 242,648 snakebite victims (95%CrI 209,810–291,023) of which 15,909 (95%CrI 7,592–33,949) were dead and 954 (95%CrI 383–1,797) were amputated. We estimated that 161,835 snakebite victims (69% of victims who were indicated for antivenom treatment) were not treated with antivenom. Annual disease burden of snakebite was estimated at 391,979 DALYs (95%CrI 187,261–836,559 DALYs) with total costs of 2.5 billion USD (95%CrI 1.2–5.4 billion USD) that were equivalent to 0.09% (95%CrI 0.04–0.20%) of the region’s gross domestic product. >95% of the estimated burdens were attributed to premature deaths.

Conclusion/Significance

The estimated high burden of snakebite in ASEAN was demonstrated despite the availability of domestically produced antivenoms. Most burdens were attributed to premature deaths from snakebite envenoming which suggested that the remarkably high burden of snakebite could be averted. We emphasized the importance of funding research to perform a comprehensive data collection on epidemiological and economic burden of snakebite to eventually reveal the true burden of snakebite in ASEAN and inform development of strategies to tackle the problem of snakebite.

Bibliometric Analysis of Literature in Snake Venom-Related Research Worldwide (1933–2022)

Simple Summary

Around the world, snake envenomation poses a serious health risk. Proteins with pharmacological effects are present in snake venom. Recent studies elaborate snake venom and its potential application, including as a cancer drug and antibacterial substances. Our study aimed to analyze the global profile of the literature in snake venom research from documents indexed in the Scopus database between 1933 and 2022. In total, 2999 documents were published with Brazil showing the highest productivity. Antivenom, proteomics, and transcriptomics are emerging as hot topics on a global scale. The present study offers a distinctive overview of snake venom research conducted worldwide.

Abstract

Snake envenomation is a severe economic and health concern affecting countries worldwide. Snake venom carries a wide variety of small peptides and proteins with various immunological and pharmacological properties. A few key research areas related to snake venom, including its applications in treating cancer and eradicating antibiotic-resistant bacteria, have been gaining significant attention in recent years. The goal of the current study was to analyze the global profile of literature in snake venom research. This study presents a bibliometric review of snake venom-related research documents indexed in the Scopus database between 1933 and 2022. The overall number of documents published on a global scale was 2999, with an average annual production of 34 documents. Brazil produced the highest number of documents (n = 729), followed by the United States (n = 548), Australia (n = 240), and Costa Rica (n = 235). Since 1963, the number of publications has been steadily increasing globally. At a worldwide level, antivenom, proteomics, and transcriptomics are growing hot issues for research in this field. The current research provides a unique overview of snake venom research at global level from 1933 through 2022, and it may be beneficial in guiding future research.

Investigations on the Changes of Serum Proteins in Rabbits after Trimeresurus stejnegeri Venom Injection via Mass Spectrometry-Based Proteomics

Purpose

There are few studies on protein phosphorylation in the process of snake poisoning. The purpose of this study was to investigate the toxic mechanism of Trimeresurus stejnegeri at the protein level by determining the differential expression of phosphorylated proteins in rabbits after poisoning using proteomics.

Methods

The Trimeresurus stejnegeri venom model in rabbits was established by intramuscular injection of 20 mg/kg venom. The serum was collected and the differential expression of phosphorylated proteins in the serum was determined by the iTRAQ technology, TiO2 enriched phosphorylated peptides, and the mass spectrometry analysis. The functional analysis was conducted using ClueGO software and the related mechanism was evaluated by the network analysis of biological interaction. The expression level of related proteins was determined by the Western blotting assay.

Results

Compared to the control group, 77 differentially expressed proteins were observed in the model group. These proteins were closely associated with the complement and agglomerate cascade signaling pathways, the HIF signaling pathway, the pentose phosphate pathway, and the cholesterol metabolism signaling pathway. According to the results of network analysis, TF and SCL16A1 were determined as the core proteins, which were identified by the Western blotting assay.

Conclusion

The present study provided valuable phosphorylation signal transduction resources for investigating the toxic mechanism and the therapies for Trimeresurus stejnegeri poisoning.