Characteristics and relative numbers of lethal snake bite cases in medicolegal practice in central Myanmar - A five year study

Rapid identification of bilateral adrenal and pituitary haemorrhages induced by Russell's viper envenomation results in positive patient outcome

The clinical management of snakebite envenomation (SBE) is challenging in many tropical and subtropical regions of developing countries due to the complex clinical manifestations and inadequate medical infrastructure. Some venomous snakes, such as the Indian Russell's viper (Daboia russelii) cause a wide range of rare complications in addition to their classical envenomation effects. In general, these uncommon complications are often misdiagnosed or not treated promptly due to a lack of awareness about these conditions. Thus, it is critical to report such complications to draw the attention of the healthcare and research communities to improve the clinical management and scientific research of SBE, respectively. Here, we report bilateral adrenal and pituitary haemorrhages in an SBE patient following a bite by Russell's viper in India. The initial symptoms included gum bleeding, swelling, axillary lymphadenopathy and clotting abnormalities. Despite the administration of antivenom, the patient presented palpitation, nausea, and abdominal pain, which were not recovered by combinational therapy with epinephrine and dexamethasone. Further infusion of antivenom did not address these issues and the patient displayed persistent hypotension, hypoglycaemia and hyperkalaemia suggesting an adrenal crisis. Inadequate secretion of corticosteroids was confirmed by laboratory tests, and imaging investigations revealed haemorrhages in both the adrenal and pituitary glands. The patient made a full recovery after treatment with hydrocortisone and thyroxine. This report adds to the growing evidence of rare complications induced by Russell's viper envenomations and it provides relevant guidance to diagnose and treat such complications in SBE victims.

Fatal Sea Snake Envenomation

ABSTRACT

A 23-year-old man working on a prawn trawler off the Northern Australian coast was bitten on the right hand by a black-banded sea snake (Laticauda colubrina), resulting in the rapid onset of ptosis, blurred vision, and respiratory difficulties with convulsions, loss of consciousness, and death. Resuscitation was unsuccessful. No antivenom was available because of the remote location. At autopsy, a small puncture wound was identified on the middle interphalangeal joint of the right little finger. No other significant abnormalities were detected. Elevations in creatine kinase (1558 μ/L) and myoglobin (24,800 μg/L) levels were found. Death was caused by respiratory failure after sea snake envenomation. This case demonstrates potential difficulties in establishing the diagnosis of lethal sea snake envenomation, including the inconspicuous nature of the bite marks with no local reaction and the underlying neurotoxic nature of the lethal mechanisms, which leaves very nonspecific pathological findings. Myonecrosis may occur but is variable. Unless reliably witnessed, sea snake envenomation may not be suspected. Failing vision or unexplained paresis in fishermen or individuals who have been in the sea may point to the diagnosis.

Systematic Review of Human Poisoning and Toxic Exposures in Myanmar

The International Health Regulations (2005) promote national capacity in core institutions so that countries can better detect, respond to and recover from public health emergencies. In accordance with the ‘all hazards’ approach to public health risk, this systematic review examines poisoning and toxic exposures in Myanmar. A systematic literature search was undertaken to find articles pertaining to poisoning in Myanmar published between 1998 and 2020. A number of poisoning risks are identified in this review, including snakebites, heavy metals, drugs of abuse, agrochemicals and traditional medicine. Patterns of poisoning presented in the literature diverge from poisoning priorities reported in other lower-middle income countries in the region. The experience of professionals working in a Yangon-based poison treatment unit also indicate that frequently observed poisoning as a result of pharmaceuticals, methanol, and petroleum products was absent from the literature. Other notable gaps in the available research include assessments of the public health burden of poisoning through self-harm, household exposures to chemicals, paediatric risk and women’s occupational risk of poisoning. There is a limited amount of research available on poisoning outcomes and routes of exposure in Myanmar. Further investigation and research are warranted to provide a more complete assessment of poisoning risk and incidence.

Vehicle fatalities involving collisions with kangaroos

A search was undertaken of the Forensic Science South Australia (FSSA), Australia, autopsy database over a 20-year period from 2000 to 2019 for all cases where vehicle crashes had involved kangaroos. There were six cases with an age range of 18-62 years (M=42 years) and a male-to-female ratio of 5:1. There were three crashes involving motor vehicles and three involving motorcycles. The three motor-vehicle crashes were initiated by impact with a kangaroo followed by a head-on crash with a truck (n=1) and a tree (n=2). In two of the motorcycle crashes, the cycle hit a kangaroo, resulting in the rider being unseated. In the third case, following impact with the animal, the cyclist hit a tree. In one of the latter cases, the only evidence of impact with a kangaroo was fur found by investigating officers adherent to the front-right indicator. Lethal injuries were located in the chest in six cases, the cranio-cervical region in five cases and the abdomen in three cases. Thus, in the majority of cases (n=5), death was due to multiple injuries. In the remaining case, death was caused by blunt chest trauma. This study shows that kangaroo-vehicle impacts may result in very significant blunt-force trauma. Motorcycle riders are particularly vulnerable. It may be only by careful examination of the vehicle/motorcycle for animal residues that the nature of the incident will be clarified.

Endocrine and Metabolic Manifestations of Snakebite Envenoming

Snakebite envenoming is a neglected, public health problem in tropical and subtropical regions. Local tissue necrosis, neurotoxic, and hemo-vasculotoxic effects are well-recognized features, whereas the endocrine and metabolic derangements are not as well known. In addition to contributing to morbidity, some of these manifestations can be potentially life-threatening if not recognized early. The most prominent endocrine manifestation is hypopituitarism (HP), which can manifest acutely or remain asymptomatic and present years later. Unexplained recurrent hypoglycemia and refractory hypotension are early clinical clues to suspect corticotroph axis involvement in acute settings. Chronic pituitary failure may present, like Sheehan's syndrome, several years after the bite. The occurrence of acute kidney injury, capillary leak syndrome, and disseminated intravascular coagulation are predictors of HP. Adrenal hemorrhages are documented in autopsy series; however, primary adrenal insufficiency is very rare and confounded by the presence of HP. Hyponatremia, hypokalemia or hyperkalemia, and dysglycemia can occur, but the mechanisms involved are only partially understood. Awareness, a high index of suspicion, correct interpretation of hormonal parameters, and timely treatment of these abnormalities can be lifesaving.

Snakebite Envenoming a Challenging Diagnosis for the Forensic Pathologist: A Systematic Review

Snakebite envenoming (SBE) is a public health issue in developing countries. The estimated annual global incidence of snakebites is about 5.4 million snakebites per year, resulting from 1.8 to 2.7 million cases of SBE and from 81,000 to 138,000 deaths with 400,000 survivors suffering permanent physical and psychological disabilities. There are more than 3000 species of snakes around the world: 600 are venomous and over 200 are considered to be medically important because of their clinical effects. The severity of SBE depends on several factors among which bite localization, snake's size, condition of glands and teeth, bite angle and bite duration, the microflora of the snake's mouth and victim's skin, age of the victim, weight, health status, and victim's activity after a bite. Snake venoms are mixtures of protein families, and each of these families contains many different toxins or toxin isoforms. Based on their effects, snake venoms can be classified as hemotoxic, neurotoxic, or cytotoxic and they can all act together involving multiple tissues and organs. When the bite is fatal, the mechanism of death is primarily related to the paralysis of respiratory muscles, which causes asphyxia and hypoxic-ischemic encephalopathy, but also anaphylactic shock, hemorrhagic shock, cardiomyopathy, acute tubular necrosis (ATN). The purpose of this literature review is to evaluate epidemiological and post-mortem examination findings in fatal SBEs in order to better understand the pathophysiological mechanisms, thus helping pathologists in defining the correct diagnosis.

Combining in silico and in vitro approaches to identification of potent inhibitor against phospholipase A2 (PLA2)

Phospholipase A2 (PLA2) is the main constituent of snake venom. PLA2 enzymes catalyze the Ca²⁺ dependent hydrolysis of 2-acyl ester bonds of 3-sn-phospholipids, releasing fatty acids and lysophospholipids. Inside the body of the victim, PLA2 from snake venom induces either direct or indirect pathophysiological effects, including anticoagulant, inflammatory, neurotoxic, cardiotoxic, edematogenic, and myotoxic activities. Therefore, there is a need to find the potential inhibitors against PLA2 responsible for snakebite. In this study, we employed in silico and in vitro methods to identify the potential inhibitor against PLA2. Virtual screening and molecular docking studies were performed to find potent inhibitor against PLA2 using Traditional Chinese Medicine Database (TCM). Based on these studies, Scutellarin (TCM3290) was selected and calculated by density functional theory calculation at B3LYP/6-31G**⁺⁺ level to explore the stereo-electronic features of the molecule. Further, molecular docking and DFT of Minocycline was carried out. Quantum polarized ligand docking was performed to optimize the geometry of the protein-ligand complexes. The protein-ligand complexes were subjected to molecular dynamics simulation and binding free energy calculations. The residence time of a protein-ligand complex is a critical parameter affecting natural influences in vitro. It is nonetheless a challenging errand to expect, regardless of the accessibility of incredible PC assets and a large variety of computing procedures. In this metadynamics situation, we used the conformational flooding technique to deal with rank inhibitors constructions. The systematic free energy perturbation (FEP) protocol and calculate the energy of both complexes. Finally, the selected compound of TCM3290 was studied in vitro analysis such as inhibition of PLA2 activity, hyaluronidase activity and fibrinogenolytic activity. The TCM3290 had a more binding affinity compare to Minocycline, and interacted with the key residues of TYR63 and GLY31. DFT represented the highest HOMO and LUMO energy of 0.15146 eV. MD simulation with 100 ns proved that an inhibitor binding mode is more stable inside the binding site of PLA2. In vitro analysis shows that TCM3290 significantly neutralized by PLA2. The above observations confirmed that Scutellarin (TCM3290) had a potent snake venom neutralizing capacity and could hypothetically be used for therapeutic drives of snakebite envenomation.