Medically important snakes and snakebite envenoming in Iran

Snakebite Envenomation From the Large Palearctic Viper, Macrovipera razii (Squamata: Serpentes; Viperidae), in Fars Province, Southern Iran

Snakebites are a significant health issue, especially in tropical and subtropical regions. Envenomation from snakebites is a clinical emergency requiring prompt treatment. Recently, a new species of blunt-nosed viper, Macrovipera razii, was identified in central and southern Iran through morphological and molecular studies. This large, dangerous viper can deliver substantial amounts of venom. Following reports to the Faculty of Health at Shiraz University of Medical Science (SUMS), the identification of venomous snakes involved in envenomation cases in Fars province was undertaken. Approximately 20 snakes were captured and presented by locals, while others provided photos. Despite some information being photo-based, the data highlighted the significant role of this viper in envenomation cases. Macrovipera razii is now recorded from 12 counties in Fars province. One incident involved a male bitten in Shiraz, and another case led to a male needing limb amputation. This study emphasizes the importance of this newly described viper in recent snakebite envenomations in the region and reviews its distribution within the Fars province.

Design, development and preclinical assessment of MENAVip-ICP, a new snake antivenom with potential coverage of species in the Middle East and North Africa regions

Snakebite in the Middle East and North Africa (MENA) is a public health problem whose magnitude is not fully known. Several antivenoms are available in these regions, but these formulations are designed for restricted geographical settings. Many countries do not have local production of antivenoms and must access products whose clinical performance has not been demonstrated. We hypothesize that it is possible to unify the treatment for viperid snakebites of MENA in a single antivenom formulation. Hereby we describe the design, development and preclinical evaluation of an antivenom of broad geographical coverage for this region (MENAVip-ICP). We produced this antivenom from the plasma of horses immunized with eight medically important venoms of viperid snake species from MENA. For this, we used a strategy based on two stages: first, immunization of horses with North African (NA) venoms, followed by a second immunization stage, on the same horses, with MENA venoms. We purified antivenoms from both stages: the Anti-NA and the final product Anti-MENA (MENAVip-ICP). Anti-NA was considered as intermediate formulation and was purified with the intention to study the progression of the immunoglobulin immune response of the horses. Antivenoms from both stages neutralized lethal, hemorrhagic, and procoagulant activities of homologous venoms. Compared to Anti-NA, MENAVip-ICP improved the neutralization profile of intravenous lethality and in vitro procoagulant activities of venoms. A notable finding was the difference in the neutralization of lethality when MENAVip-ICP was assessed intraperitoneally versus intravenously in the murine model. Intraperitoneally, MENAVip-ICP appears more effective in neutralizing the lethality of all venoms. Furthermore, MENAVip-ICP neutralized the lethal activity of venoms of species from other regions of MENA, Central/East Asia, and Sub-Saharan Africa that were not included in the immunization protocol. Our results showed that MENAVip-ICP neutralizes the main toxic activities induced by viperid MENA venoms at the preclinical level. Consequently, it is a promising product that could be clinically assessed for the treatment of snakebite envenomings in this region.

Development and characterization of nanobody against envenomation by Naja naja oxiana

Snakebites are considered a significant health issue. Current antivenoms contain polyclonal antibodies, which vary in their specificity against different venom components. Development and characterization of next generation antivenoms including nanobodies against Naja naja oxiana was the main aim of this study. Crude venom was injected into the Sephadex G50 filtration gel chromatography column and then toxic fractions were obtained. Then the corresponding fraction was injected into the HPLC column and the toxic peaks were identified. N. naja oxiana venom was injected into a camel and specific nanobodies screening was performed against the toxic peak using phage display technique. The obtained results showed that among the 12 clones obtained, N24 nanobody was capable of neutralizing P1, the most toxic peak obtained from HPLC chromatography. The molecular weight of P1 was measured with a mass spectrometer and was found to be about seven kDa. The results of the neutralization test of crude N. naja oxiana venom with N24 nanobody showed that 250 μg of recombinant nanobody could neutralize the toxic effects of 20 μg equivalent to LD50 × 10 of crude venom in mice. The findings indicate the potential of the developed nanobody to serve as a novel antivenom therapy.

Treatment response and clinical features of snakebite envenomation in Alborz province, Iran: A cross-sectional study

Background

Snakebite envenomation is a significant yet neglected public health burden. Our aim was to investigate the clinical and demographic factors of snakebite envenomation, as well as the factors associated with its severity and response to treatment, in Alborz province, northern Iran.

Methods

In this cross-sectional study, we included 50 patients diagnosed with snakebite envenomation, referring to the Poison Control Centre of Alborz University of Medical Sciences. The presenting signs and symptoms, demographic data, treatment dose, response to treatment, complications, laboratory findings, and snakebite severity scale (SSS) were collected.

Results

Forty-six patients (92%) were men, the total mean age was 31.7 ± 12.06 years, and mean SSS was 6.54 ± 3.39. The patients were admitted for a median of 2 days, and 11 patients needed ICU admissions. The majority of snakebites were in upper extremities (60%) and they mainly occurred in summer (56%). SSS was significantly associated with response to treatment, ICU admission, gastrointestinal adverse events, thrombocytopenia, and length of stay. Similarly, response to treatment was significantly related to the history of snakebite, ICU admission, gastrointestinal adverse events, thrombocytopenia, length of stay, and SSS.

Conclusion

Gastrointestinal symptoms, higher severity scores, and longer hospital stays were associated with poor treatment response. Importantly, no mortality was observed in this cohort. Further research is needed to confirm these findings and optimize treatment strategies for snakebite management.

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.

Venomics of the milos viper (Macrovipera schweizeri) unveils patterns of venom composition and exochemistry across blunt-nosed viper venoms

Introduction: Snakebite is a neglected tropical disease and a globally important driver of death and morbidity. Vipers of the genus Macrovipera (Viperidae: Viperinae) are among the snakes of higher medical importance in the Old World. Despite the medical relevance of Macrovipera venoms, the knowledge regarding them is heterogeneously distributed with virtually all works conducted so far focusing on subspecies of Macrovipera lebetinus, while other species within the genus are largely overlooked. Here we present the first proteomic evaluation of the venom from the Greek endemic Milos viper (Macrovipera schweizeri). In line with clinical symptoms typically elicited by Macrovipera envenomations, Milos viper venom primarily comprises coagulotoxic and cytotoxic protein families, such as metalloproteinases (svMP) and serine proteases (svSP). Methods: We conducted comparative bioactivity assays on venoms from M. schweizeri and the M. lebetinus subspecies M. lebetinus cernovi, M. lebetinus obtusa, and M. lebetinus turanica, and showed that they all exhibit similarities in levels of cytotoxicity proteolytic activity, and inhibition of prokaryotic growth. Lastly, we compared Macrovipera venom profiles by 1D-SDS-PAGE and RP-HPLC, as well as our proteomic data with previously published Macrovipera venom proteomes. Results and discussion: The analyzes performed to reveal that a general venom profile seems to be conserved across blunt-nosed vipers, and that, M. schweizeri envenomations, similarly to those caused by other blunt-nosed vipers, are able to cause significant tissue damage. The present work represents an important starting point for the development of comparative studies across the full taxonomic range of the genus Macrovipera and can potentially help optimize the treatment of envenomations caused by M. schweizeri.

Identifying the geographic distribution pattern of venomous snakes and regions of high snakebite risk in Iran

We describe species richness patterns of venomous snakes in Iran in order to produce snakebite risk prediction maps and identify gaps in regional health care centers capable of managing snakebites. We digitized distribution maps from the literature, Global Biodiversity Information Facility (GBIF), and the results of our own field studies of 24 terrestrial venomous snake species (including 4 endemic to Iran). Species richness patterns were associated with eight environmental factors. The variables have been extracted from the WorldClim dataset (bio12 = annual precipitation, bio15 = precipitation seasonality, bio17 = precipitation of the driest quarter, bio2 = mean diurnal range, bio3 = isothermality (bio2/bio7), bio4 = temperature seasonality, bio9 = mean temperature of the driest quarter and slope). Based on spatial analyses, species richness in Iran is highly affected by three environmental variables (bio12, 15, and 17) associated with precipitation. The relationship patterns among these predictors and species richness were strong and linear. The hotspot regions for venomous snakes species are concentrated on the western to southwestern and north to northeastern regions of Iran, which is partially consistent with the known Irano-Anatolian biodiversity hotspot. Because of the high number of endemic species and climatic conditions on the Iranian Plateau, the venoms of snakes distributed in those areas may contain novel properties and components.