Severe scorpion envenomation: pathophysiology and the role of inflammation in multiple organ failure

Effect of animal venom toxins on the main links of the homeostasis of mammals (Review)

The human body is affected by environmental factors. The dynamic balance between the organism and its environment results from the influence of natural, anthropogenic and social aspects. The factors of exogenous origin determine development of adaptive changes. The present article summarises the mechanisms of animal venom toxins and homeostasis disruption in the body of mammals. The mechanisms underlying pathological changes are associated with shifts in biochemical reactions. Components of the immune, nervous and endocrine systems are key in the host defense and adaptation processes in response to venom by triggering signalling pathways (PI3kinase pathway, arachidonic acid cascade). Animal venom toxins initiate the development of inflammatory processes, the synthesis of pro-inflammatory mediators (cytokines), ROS, proteolytic enzymes, activate the migration of leukocytes and macrophages. Keratinocytes and endothelial cells act as protective barriers under the action of animal venom toxins on the body of mammals. In addition, the formation of pores in cell membranes, structural changes in cell ion channels are characteristic of the action of animal venom toxins.

Clinical, epidemiological and faunistic characterization of scorpionism in Azilal, Central High Atlas (Morocco)

The province of Azilal is one of the most scorpion-infested areas in Morocco. The current study aims to investigate the clinical and epidemiological characteristics of scorpion envenomation in the Azilal province, as well as to contribute to the study of its scorpio-faunistic diversity. We examined clinical and epidemiological data from 5684 scorpion stings recorded between 2017 and 2021. Prospections on the ground were carried out in the study area. The species were identified using the taxonomic keys. Distribution maps of inventoried species have been created using SIG. 5684 scorpions stings were reported in the study area, with 18 cases of deaths. Most of the cases was reported in the summer especially at night (64%). A positive significant correlation was found between scorpion stings incidence and season (P < 0.005; r = 0.56). A positive correlation was found between scorpion stings incidence and mortality (r = 0.09). Pediatric mortality was higher compared to lethality in adults (P < 0.05). A positive correlation was found between the number of stung children (Age <15 years) and the number of patients presenting clinical signs of severe envenomation (Class III) (r = 0.40). The percentage of patients that use traditional remedies was significantly higher in the rural areas (P < 0.05). Most scorpion stings occurred in human habitat (54.5%) or in their neighbourhood (24.5%). Six species were identified in the study area. The findings of this study have highlighted the extent of scorpion envenomation and have elucidated certain characteristics of the scorpio-faunistic biodiversity in the Azilal province.

The Activity of Metalloproteases and Serine Proteases in Various Organs after Leiurus macroctenus Envenomation

Background

Scorpion stings may be life-threatening since their venoms are comprised of a wide range of toxins and other bioactive molecules, such as enzymes. At the same time, scorpion envenomation may increase matrix metalloproteases (MMPs) levels, which enhance proteolytic tissue destruction by venom. However, investigations on the impact of many scorpions' venoms, such as those of Leiurus macroctenus, on tissue proteolytic activity and MMP levels have not yet been conducted.

Methods and Results

The present study aimed to examine the total proteolysis levels in various organs after Leiurus macroctenus envenomation and evaluate the metalloproteases and serine proteases' contributions to the total proteolytic activity. Changes in MMPs and TIMP-1 levels were tested as well. Envenomation led to a significant increase in proteolytic activity levels in all assessed organs, mostly in the heart (by 3.34 times) and lungs (by 2.25 times).

Conclusions

Since EDTA presence showed a noticeable decrease in total proteolytic activity level, metalloproteases appeared to play a prominent role in total proteolytic activity. At the same time, MMPs and TIMP-1 levels were increased in all assessed organs, suggesting that Leiurus macroctenus envenomation causes systemic envenomation, which may induce multiple organ abnormalities, mostly because of the uncontrolled metalloprotease activity.

[Inverted Takotsubo Syndrome due to Severe Scorpion Envenomation: Report of one Case]

Scorpion envenomation (SE) is common in tropical and subtropical regions. Cardio-respiratory manifestations, mainly cardiogenic shock and pulmonary oedema are the leading causes of death after scorpion envenomation. Cardiac failure can be due to massive release of catecholamines, myocardial damage induced by the venom or myocardial ischemia. Although it has been exceptionally reported, Takotsubo syndrome during SE can help to better elucidate the pathophysiology of this cardiomyopathy. We report a case of inverted Takotsubo following a SE in a 26-year-old patient admitted to the Intensive care unit department for severe scorpion envenomation. His evolution was favorable. We concluded that cardiac involvement in this case fulfills all clinical and paraclinical criteria of Takotsubo syndrome emphasizing the importance of catecholaminergic discharge during scorpion envenomation. We discuss again the management of this syndrome in this specific condition.