Snakebite Management and One Health in Asia Using an Integrated Historical, Social, And Ecological Framework.

Snakebite envenomation continues to contribute to high fatality and morbidity rates across Asia. Yet snake bite is one of many outcomes due to human-snake conflicts, which themselves are only one type of human-snake relationship among the diversity of such interactions. We propose that human-snake relationships need to be explored from a perspective integrative of history, ecology, and culture in order to adequately and holistically address snake bite. In order to contextualize this concept within a language already understood in conservation research, we characterize and develop four interconnected themes defining human-snake relationships as a social ecological system. By breaking down the multifaceted nature of human-snake relationships under a social ecological systems framework, we explore its applicability in contributing to a unified strategy, drawing from both social and natural sciences for ending the snakebite crisis.

Epidemiological study of snakebite cases in Sikkim: Risk modeling with regard to the habitat suitability of common venomous snakes.

BACKGROUND: Snakebite envenoming is listed as category 'A' Neglected Tropical Disease. To achieve the target of WHO (World Health Organization) 2019, it becomes necessary to understand various attributes associated with snakebite including community awareness, improvisation of medical facilities and to map the potential distribution of venomous snakes responsible for the bite. Hence this study is conducted in Sikkim, India to understand the epidemiology of snakebite in Sikkim. The potential distribution and risk mapping of five common venomous snakes are done for effective management of snakebite cases. METHODS AND FINDINGS: The snakebite cases registered in six district hospitals and four PHCs (Primary Health Centers) of Sikkim were collected from the year 2011 to 2018. Community survey was also conducted to supplement the data. Ecological Niche Modeling (ENM) was performed to predict the potential habitat of five common venomous snakes of Sikkim. The risk modeling of snakebite cases was done at the level of Gram Panchayat Unit (GPU) using Geographically Weighted Regression (GWR) and Ordinary Linear Square (OLS) model. We found higher number of male victims inflicted with snakebite envenomation. The potential distribution of the five venomous snakes showed satisfactory mean AUC (Area under Curve) value. Both the models showed significant positive association of snakebite cases with habitat suitability of the venomous snakes. Hospital data revealed no death cases whereas community data reported 24 deaths. CONCLUSIONS: Death from snakebite reflected in community data but not in hospital data strongly indicates the people's belief in traditional medicine. Though people of Sikkim have rich traditional knowledge, in case of snakebite traditional practices may be ineffective leading to loss of life. Sensitizing people and improving medical facilities along with proper transport facilities in rural areas might significantly reduce the snakebite casualties in the state.

How beliefs in traditional healers impact on the use of allopathic medicine: In the case of indigenous snakebite in Eswatini.

Snakebite is a major public health problem in Eswatini and serious envenomations can be responsible for considerable morbidity and mortality if not treated correctly. Antivenom should be administered in hospital in case of adverse reactions and any delays due to distance, transport, costs, antivenom availability and cultural beliefs can be critical. Myths and superstition surround snakes, with illness from snakebite considered a supernatural phenomenon best treated by traditional medicine since healers can explore causes through communication with the ancestors. Traditional consultations can cause significant delays and the remedies may cause further complications. Four rural focus group discussions were held in varying geographical regions to establish why people may choose traditional medicine following snakebite. The study revealed four themes, with no apparent gender bias. These were 'beliefs and traditions', 'logistical issues', 'lack of knowledge' and 'parallel systems'. All snakes are feared, regardless of geographical variations in species distribution. Deep-seated cultural beliefs were the most important reason for choosing traditional medicine, the success of which is largely attributed to the 'placebo effect' and positive expectations. Collaboration and integration of the allopathic and traditional systems assisted by the regulation of healers and their methods could improve future treatment success. The plight of victims could be further improved with more education, lower costs and improved allopathic facilities.

Taxonomical outlines of bio-diversity of Karnataka in a 14th century Kannada toxicology text Khagendra Mani Darpana.

Origin of ancient Indian toxicology can be dated back to vedic literature. Toxins of both animate and inanimate world were very well understood during the era. Rig and Atharva vedic texts describe such details. After classifying such toxins, Charaka Samhitha, the basic literature of Indian Medicine used gold and ghee as panaceas to counter act them. Ayurveda considers toxicology as one among the eight specialized branches of medical wisdom. Unfortunately, the available literature on this is very limited. Moreover, they have been discussed briefly in Charaka and Sushrutha Samhitha. Mangarasa I, a Jain scholar who lived on the foothills of the Western Ghats, in Southern India in 1350 A.D., felt this vacuum and composed an independent, elaborate Kannada text on toxicology. His less known text Khagendra Mani Darpana (KMD) is the first ever documented complete text on toxicology in the world. Medieval Indian wisdom on plant and animal diversities are very well reflected in this unique toxicological text. Centuries past to Linnean era, KMD gives vivid descriptions on zoological and botanical diversities of the time. This astonishing fact is an evidence of our ancestor's curiosities about the nature around them. A critical overview of the bio-diversity described in KMD text is discussed in this paper.

A decentralized control scheme for an effective coordination of phasic and tonic control in a snake-like robot.

Autonomous decentralized control has attracted considerable attention because it enables us to understand the adaptive and versatile locomotion of animals and facilitates the construction of truly intelligent artificial agents. Thus far, we have developed a snake-like robot (HAUBOT I) that is driven by a decentralized control scheme based on a discrepancy function, which incorporates phasic control. In this paper, we investigate a decentralized control scheme in which phasic and tonic control are well coordinated, as an extension of our previous study. To verify the validity of the proposed control scheme, we apply it to a snake-like robot (HAUBOT II) that can adjust both the phase relationship between its body segments and the stiffness at each joint. The results indicate that the proposed control scheme enables the robot to exhibit remarkable real-time adaptability over various frictional and inclined terrains. These findings can potentially enable us to gain a deeper insight into the autonomous decentralized control mechanism underlying the adaptive and resilient locomotion of animals.

Molecular cloning and characterization of cDNAs encoding metalloproteinases from snake venom glands.

Snake venom metalloproteinases (SVMPs) are a superfamily of zinc-dependent proteases and participate in a number of important biological, physiological and pathophysiological processes. In this work, we simultaneously amplified nine cDNAs encoding different classes of metalloproteinases from glands of four different snake species (Agkistrodon contortrix laticinctus, Crotalus atrox, Crotalus viridis viridis and Agkistrodon piscivorus leucostoma) by RT-PCR with a pair of primers. Among the encoded metalloproteinases, two enzymes (AclVMP-I and AplVMP-I), three enzymes (CaVMP-II, CvvVMP-II and AplVMP-II) and four enzymes (AclVMP-III, CaVMP-III, CvvVMP-III and AplVMP-III) with the characteristic motif (HEXXHXXGXXH) of metalloproteinase belong to type P-I, P-II and P-III enzymes, respectively. Disintegrin domains of CaVMP-II and CvvVMP-II from two Crotatus snakes contain RGD-motif whereas AplVMP-II from Agkistrodon snake has KGD-motif. Instead of R/KGD-motif within disintegrin domain of SVMP-II enzyme, CaVMP-III, CvvVMP-III and AplVMP-III enzymes contain SECD-motif, while AclVMP-III has DDCD-motif in their corresponding position of disintegrin-like domains. There are 12 Cys amino acids in cysterin-rich domains of each P-III enzyme. Moreover, a disintegrin precursor (AplDis) with RGD-motif also simultaneously amplified from the glands of A.p. leucostoma while amplifying AplVMP-II and AplVMP-III, which indicated that different types of SVMPs and related genes are present in a single species of snake and share a consensus sequence at the 3' and 5' untranslated regions. RT-PCR result also showed that P-III is highly expressed in Crotalus snakes than in Agkistrodon snakes. Aligning the deduced amino acid sequence of these enzymes with other SVMPs from GenBank database indicated that this is the first report on the isolation of cDNAs encoding P-II and P-III enzymes from C.v. viridis and A.p. leucostoma snakes. The availability of these SVMP sequences directly facilitated further studies of structure characterization and diversified function analysis.

Differential effects of courtship and mating on receptivity and brain metabolism in female red-sided garter snakes (Thamnophis sirtalis parietalis).

In the female red-sided garter snake (Thamnophis sirtalis parietalis), the loss of receptivity following intromission during mating can be prevented by injection of a local anesthetic (tetracaine) in the cloacal region prior to courtship and mating. Females that were courted and then mated had significantly higher uptake of radio-labeled [14C]2-fluoro-2-deoxyglucose (2-DG) in the preoptic area (25%) and significantly lower uptake in the ventromedial hypothalamus (-20%) compared with females that were courted but not mated. Tetracaine-treated females had accumulation patterns similar to courted but unmated females and to females exposed only to other females. These results suggest that in the female red-sided garter snake, sensory input from the cloaca during mating alters patterns of metabolism in those brain areas most often associated with female sexual behavior.

Neural substrates for processing chemosensory information in snakes.

Snakes interact with their chemical environment through their olfactory and vomeronasal systems. The present report summarizes advances on neural substrates for processing chemosensory information. First, the efferent and centrifugal afferent connections of the main and accessory olfactory bulbs were reinvestigated. Second, the afferent and efferent connections of the nucleus sphericus, the main target of the accessory olfactory bulb, were characterized. The nucleus sphericus gives rise to a very small projection to the hypothalamus, but it does project to other telencephalic structures where olfactory and vomeronasal information could converge. Third, the intra-amygdaloid circuitry and the amygdalo-hypothalamic projections were described. The medial amygdala, for instance, receives both vomeronasal and olfactory inputs and projects to the hypothalamus, namely, to the lateral posterior hypothalamic nucleus. Fourth, because the lateral posterior hypothalamic nucleus projects to the hypoglossal nucleus, the motor center controlling the tongue musculature, this projection could constitute a pathway for chemosensory information to influence tongue-flicking behavior. In summary, vomeronasal information is mostly relayed to the hypothalamus not via the nucleus sphericus but through other telencephalic structures. Convergence of olfactory and vomeronasal information appears to occur at different levels in the telencephalon. A neural substrate for the chemosensory control of tongue-flicking behavior is provided.

Seasonal fluctuations in brain nuclei in the red-sided garter snake and their hormonal control.

In many vertebrates, breeding seasons are protracted and mating behavior is temporally associated with gonadal growth and increased sex steroid hormone secretion. In the red-sided garter snake (Thamnophis sirtalis parietalis), mating behavior is restricted to the 2-4 weeks immediately following emergence from winter dormancy. During this period mating behavior is sex-specific: chin-rubbing is exhibited only by males and receptivity to chin-rubbing is exhibited only by females. It is remarkable that mating occurs when the gonads are small and circulating concentrations of gonadal hormones are low. As in other vertebrate species, limbic nuclei are involved in the mediation of mating behaviors. To determine if limbic nuclei are sexually dimorphic and, further, whether they fluctuate in size with the seasons, the volume of brain areas was measured in both sexes at different times of the year (spring, fall, hibernation) and after hormone manipulation (gonadectomy and gonadectomy plus hormone treatment). The areas of interest were the preoptic area (POA), ventromedial hypothalamus (VMH), and the nucleus sphericus (NS or amygdala); control areas included the external nucleus of the optic tract (a cell-rich area) and medial forebrain bundle (a fiber-rich area). Comparisons according to season and manipulation revealed only two instances of sexual dimorphism: the POA of females was significantly smaller than that of males during hibernation and the NS of females was significantly smaller than that of males in those animals not subjected to hibernation. This general lack of sexual dimorphisms in the brain despite the sex-specificity of the behavior patterns and their marked seasonality may reflect the dissociated reproductive pattern characteristic of this species.(ABSTRACT TRUNCATED AT 250 WORDS)

[Increase in the number of colloidal droplets in the hypothalamus of Natrix maura caused by dehydration]. / Incremento del número de gotas coloidales en el hipotálamo de Natrix maura por la deshidratación.

The influence of osmotic stress on the number of colloid droplets in the magnocellular neurosecretory nuclei of the water snake Natrix maura, has been studied. Five experimental groups of five specimens each, were submitted to dehydration by immersion in sea water for several periods of time (3 to 60 h). The number of colloid droplets, identified by histochemical procedures, was counted in serial sections of the retrochiasmatic nuclei. The study of the mean of each group revealed that the amount of colloids increased with the time of permanence in the hyperosmotic environment (48 h elicited the greatest response). As a conclusion, dehydration seems to activate the hypothalamic magnocellular neurosecretory nuclei of N. maura and, consequently, increases the production of colloid droplets.

Trigeminal responses to thermal stimulation of the oral cavity in rattlesnakes (Crotalus viridis) before and after bilateral anesthetization of the facial pit organs.

Multiunit neural responses from the superficial maxillary branch of the trigeminal nerve in prairie rattlesnakes were elicited by intraoral thermal stimulation. The responses to oral stimulation were shown to be independent of responses obtained by thermal stimulation of the loreal pits. Histological examination of the dorsal lip, palate, and fang sheath regions revealed dense ramifying neurons in the epidermal layers of the fang sheaths that were morphologically similar to suspected infrared sensitive neurons in the pit membranes.