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Since December 2019, the world has been shaken by the spread of a highly pathogen virus, causing severe acute respiratory syndrome (SARS-Cov2), which emerged in Wuhan, China. SARS-Cov2 is known to cause acute pneumonia: the cardinal feature of coronavirus disease 2019 (COVID-19). Clinical features of the disease include respiratory distress, loss of spontaneous breathing, and sometimes neurologic signs such as headache and nausea and anosmia, leading to suppose a possible involvement of the nervous system as a potential target of SARS-CoV2. The chapter will shed light on the recent clinical and experimental data sustaining the involvement of the nervous system in the pathophysiology of COVID-19, based on several case reports and experimental data reporting the possible transmission of SARS-CoV2 throughout the peripheral nerves to the brain cardiorespiratory centers. Thus, understanding the role of the nervous system in the course of clinical symptoms of COVID-19 is important in determining the appropriate therapeutic approach to combat the disease.

Malaria is a mosquito-borne infectious disease caused by obligate intraerythrocytic protozoa of the genus Plasmodium. As one of the most devastating global health issues, malaria is a sensitive disease to weather and climate conditions, in such a way the ongoing trends of increasing temperature and more variable weather could lead to malaria transmission spreading. Spatial and temporal variations in precipitation, temperature, and humidity that are projected to take place under different climate change scenarios will impact the biology and ecology of malaria vectors and subsequently the risk of disease transmission. Here, the authors review how climate and climate change may impact malaria transmission. They contrast ecological and behavioral characteristics of malaria vectors and parasites and how weather, climate, climate change, and socioeconomic factors may have very different impacts on their spatiotemporal occurrence and abundance and the resulting malaria risk.

Coronaviruses are a large family of viruses that usually cause mild to moderate upper-respiratory tract illnesses, like the common cold. They were named according to the shape of glycoprotein spikes present on the viral surface and resembling to the solar corona. The first coronaviruses identified in human were HCoV 229E and the HCoV OC43, known also as β-coronavirus. This virus family has become increasingly important and received more attention within scientific community in the past two decades because of three new viruses that can cause serious, even fatal, disease. These are SARS coronavirus (SARS-CoV), which emerged in November 2002 and caused severe acute respiratory syndrome (SARS); Middle East respiratory syndrome (MERS) caused by the MERS coronavirus (MERS-CoV), identified in September 2012 and continues to cause sporadic and localized outbreaks. The third novel coronavirus to emerge in this century is called SARS-CoV-2. This chapter will describe the history of the coronavirus family discovery, emergence, and classification of the main coronaviruses.

In December 2019, the world saw the appearance of a severe acute respiratory syndrome, SARS-CoV-2, in Wuhan. The virus originated in bats and was transmitted to humans. The number of cases started increasing exponentially. According to the World Health Organization, the massive migration of Chinese during the Chinese New Year fuelled the epidemic. Cases in other provinces of China, other countries (Thailand, Japan, and South Korea in quick succession) were reported in people who were returning from Wuhan. After two months, the World Health Organization reclassified this virus as a pandemic. This virus caused a great danger in the world; most countries declared a state of emergency and implemented quarantine in order to stop the spreading of the virus. We don't yet have an effective medicine against this virus. More than 155 million people are now infected with COVID-19 and more than three million people have died. This chapter will discuss the history and spread of the COVID-19 pandemic.

The World Health Organization (WHO) recognized the coronavirus disease (COVID-19) as a worldwide pandemic caused by a newly discovered coronavirus responsible for Severe Acute Respiratory Syndrome (SARS-Cov2). The virus appeared in Wuhan, China in December 2019 and spread throughout the world, causing several mortality cases particularly in older people and those with chronic diseases. A body of evidence suggests a multi-target of SARS-Cov2, which may act beyond the respiratory system being responsible for other pathological complications, including the gastrointestinal tract, nervous, and the renal functions. The chapter will provide a literature review of the recent data on COVID-19 physiopathology involving in addition to the respiratory dysfunction all the potential physiological functions which could be independently and directly impaired by the SARS-Cov2.

The global burden of viral infection, especially the current pandemics of SARS-CoV-2, HIV/AIDS, and hepatitis, is a very risky one. Additionally, HCV expresses the necessity for antiviral therapeutic elements. Venoms are known to contain an array of bioactive peptides that are commonly used in the treatment of various medical issues. Several peptides isolated from scorpion venom have recently been proven to possess an antiviral activity against several viral families. The aim of this review is to provide an up-to-date overview of scorpion antiviral peptides and to discuss their modes of action and potential biomedical application against different viruses.

Rats animal model was used to assess the severity of symptoms produced following the Intracerebroventricular injection (ICV) of incremental doses of Buthus lienhardi scorpion venom based on histopa...

The present study investigated the toxic effects of B. lienhardi venom, at the histological, hematological, biochemical and motor skill levels following a subcutaneous injection of different doses of venom. The LD50 of B. lienhardi scorpion venom was found to be 0.27 mg/Kg by subcutaneous injection route. The results clearly indicate that B. lienhardi venom induces massive tissue damages in the organs, such as lungs, heart, kidneys and liver together with hematological impairments manifested by decreased levels of both red and white series. We further demonstrated that scorpion venom is able to alter motor system by inducing motor incoordination and reducing muscle strength. The overall results confirm that the venom from B. lienhardi primarily is a highly toxic agent and has cardiotoxic, nephrotoxic, hepatotoxic and pneumotoxic activity.

Aim: The objective of this study was to establish environmental factors related to scorpion species occurrence and their current potential geographic distributions in Morocco, to produce a current envenomation risk map and also to assess the human population at risk of envenomation. Materials and Methods: In this study, 71 georeferenced points for all scorpion species and nine environmental indicators were used to generate species distribution models in Maxent (maximum entropy modeling of species geographic distributions) version 3.3.3k. The models were evaluated by the area under the curve (AUC), using the omission error and the binomial probability. With the data generated by Maxent, distribution and envenomation risk maps were produced using the "ESRI® ArcGIS 10.2.2 for Desktop" software. Results: The models had high predictive success (AUC >0.95±0.025). Altitude, slope and five bioclimatic attributes were found to play a significant role in determining Androctonus scorpion species distribution. Ecological niche models (ENMs) showed high concordance with the known distribution of the species. Produced risk map identified broad risk areas for Androctonus scorpion envenomation, extending along Marrakech-Tensift-Al Haouz, Souss-Massa-Draa, and some areas of Doukkala-Abda and Oriental regions. Conclusion: Considering these findings ENMs could be useful to afford important information on distributions of medically important scorpion species as well as producing scorpion envenomation risk maps.

Objective To describe the species composition of scorpions and to study its geographical distribution in Laayoune-Sakia El Hamra and Dakhla-Oued Ed Dahab regions in July 2014. Methods To locate scorpions, the ground was examined through searching the places under the stones, rocks and in burrows. The nocturnal missions were also conducted using portable ultraviolet lamps. The scorpions were subsequently identified in the laboratory. Results The results of the investigations in these regions showed the presence of five scorpion species, two of which Androctonus gonneti and Buthus bonito were endemic in Morocco. Conclusions This work is allowed to complete the inventory of the studied scorpion fauna and provides some considerations on the distribution patterns in the study area.

Objective: To describe and compare the epidemiological features of scorpionism during six years (2005–2010) in two regions of Morocco: Marrakesh-Tensift-Al Haouz and Souss-MassaDraa. Methods: Clinical and epidemiological data were obtained from medical records of the Moroccan Poison Control Center during 2005–2010. The data comprised demographics, sting characteristics and clinical severity classes. Digital maps were produced for envenomation and death incidence with the distribution of all scorpion species present on the studied area. Results: A total of 75313 scorpion sting cases were notified. The incidence of scorpion stings was 244 cases/100000 population/year and was significantly higher at Marrakesh-Tensift-Al Haouz than Souss-Massa-Draa. The general lethality rate was on an average of 0.28% with a higher rate in Marrakesh-Tensift-Al Haouz compared to Souss-Massa-Draa. There was a different distribution of cases between genders in the two studied regions. With respect to age groups, adults (more than 15 years) were affected most compared to children. When analyzed according to the incidence in each province, the highest envenomation incidence was observed in Chichaoua. Concerning lethality, the highest lethality incidence was observed in the Kelaa. Based on this study, we could distinguish three zones: low scorpion stings occurrence without death, high incidence with low lethality and high scorpion stings rate with high lethality. Conclusions: Our data clearly demonstrate the correlation between scorpion stings incidence and the percentage of rural population in the different provinces. Additionally, the lethality incidence could be linked to the scorpion species of the studied area.

Central effects of scorpion venom toxins have been neglected, due both to the common belief that scorpion venoms act by targeting peripheral organs and also to the misunderstanding that these peptides do not cross the brain-blood barrier (BBB). Determining whether scorpion neurotoxicity is restricted to peripheral actions or whether a central mechanism may be partly responsible for systemic manifestations could be crucial in clinical therapy trends. The present study therefore aims to assess histopathological damages in some organs (heart, kidney, liver, and lungs) and the related biochemical impairments, together with a neurobehavioral investigation following an intracerebroventricular (i.c.v) micro-injection of Hottentotta gentili (Scorpiones, Buthidae) venom (0.47 μg/kg). I.c.v. injection of venom produced focal fragmentation of myocardial fibers, while lungs showed rupture of the alveolar structure. Concurrently, there was a significant rise in the serum enzymes levels of ASAT, ALAT, CPK and LDH. Meanwhile, we observed behavioral alterations such as a hypoactivity, and in addition the venom seems to have a marked anxiogenic-like effect. The present investigation has brought new experimental evidence of a peripheral impact of central administration of H. gentili venom, such impact was manifested by physiological and behavioral disturbances, the last of these appearing to reflect profound neuro-modulatory action of H. gentili venom.

The genus Androctonus is represented by 7 scorpion species in Morocco. All studies conducted on the characterization of Androctonus species venom are limited to Androctonus mauritanicus. However, there is other species which arouses also interest of scientists due to their high toxicity. Thus, we chose to assess the toxic effect of Androctonus liouvillei venom by sublethal injection and the effects on some vital organs, by a histological and a biochemical tools. In addition, we aimed to characterize the neurobehavioral impairments, in Swiss mice, 3h, 6h and 12h following envenomation. The LD50 of A. liouvillei scorpion venom was found to be 0.29mg/kg by subcutaneous injection route. Venom administration induced glomerular destruction and disorganization in the Bowman's spac. Examination of lungs showed a remarkable focal rupture of the alveolar structure and intra-alveolar hemorrhage. Concurrently, there was a significant enhancement in the serum enzymes levels of AST, ALT, CPK and LDH, and a high level of glucose and creatinine. Proteinuria was also observed. Regarding the behavioral effects we noted a hypoactivity and anxiogenic-like effect, manifested by an increased time spent in the open arms in groups tested 30min and 12h after the injection. Concomitantly with an increased immobility time in the tail suspension test. The present finding show an obvious profound neuromodulatory effect of A. liouvillei venom manifested by an impaired neurobehavioral and physiological patterns in mice that may in part explain the toxic effect of the venom in human as one of the potent death agents.

The incidence of emergence diseases including vector borne diseases, water diseases, and some physiologic impairment is considered sensitive to climate. Malaria, leishmaniasis, dengue, and viral encephalitis are among those diseases most influenced by climate. Variation in the incidence of vector borne diseases is associated with extreme weather events and annual changes in weather conditions. Africa in general and Morocco in particular are designated as an area of significant impact by numerous the Intergovernmental Panel on Climate Change (IPCC) reports and notably susceptible to such drastic climate-related health consequences. Climatic parameter change would directly affect disease transmission by acting on the vector's geographic range, activity, or reproduction and by reduction the period of pathogen incubation. This chapter will discuss the increasing risk of some vector-borne diseases in hazard-prone localities. It further identifies the severe challenges both of health adaptation to climate change by highlighting Moroccan adaptive capacity to such crises.

Every year, more than 1 million cases of scorpion envenomation are reported worldwide. Scorpions are thermophilic organisms. They are sensitive to weather and climate conditions, in such a way the ongoing trends of increasing temperature and more variable weather could lead to scorpionism spreading. There has been considerable debate as to whether global envenomation will be impacted by climate change which has focused on snake and spider envenomation risk. This debate didn't give enough interest to scorpion stings and its burden risks, in spite their widespread potential effects in many regions. Here, the authors review how climate and climate change may impact scorpion activity as well as scorpion envenomation. They contrast ecological and behavioral characteristics of these arthropods, and how weather, climate, climate change, and socioeconomic factors may have very different impacts on the spatiotemporal occurrence and abundance of scorpions, and the resulting scorpion envenomation.

Depression and anxiety are among the most serious disorders spread-out all over the world. In most cases, patients with depression present features of anxiety. Interestingly and inversely, patients with anxiety also present depression. Thus, both disorders may occur together, with one meeting criteria of the other. The extent of the two disorders has been shown through the high rates of their prevalence. They are, furthermore, associated with significant morbidity which shows how important is to identify and treat both illnesses. However, several epidemiological studies have reported such illnesses to be intensified with the influence of environmental factors such as the toxic effect of heavy metals. Furthermore, the influence of climate change exacerbates the negative effect of these elements. Biological and preclinical investigations have reconciled the mechanism of action by which heavy metals set off emotional disorders. Though its potential harms are important, more studies are needed to understand heavy metals' influence on the evoked pathways.

Leishmaniasis is a complex disease comprised of multiple organisms in association. Each of these organisms responds differently to external factors. The environmental and socio-economic associations contribute to the dynamics and emergence of leishmaniasis across the globe. Ecological dynamics of the vector-parasite-host system of leishmaniasis influenced directly and indirectly both human and animal health. The transitions and rapid climate and socio-economic changes caused a transition of emergence and re-emergence of leishmaniasis outbreaks. The pattern of changes is influenced by the distribution and abundance as well as the spatial dynamics of vector and reservoirs species, which in turn disrupts ecosystem structure of vector and parasite. In Morocco, leishmaniasis are endemic and constitute a major public health threat. The observations showed significant variations in its spatial distribution and forms through Morocco with increase in the number of recorded cases during the last couple of years. Here, the authors discuss disease change related to climate and socio-economic influence.

The purpose of this chapter is to examine the evidence of a relationship between climatic changes and snake species distribution in relation with the snakebites risk increment against human populations. The global climatic change is a key factor leading to snake species behavioral changes mainly because of the rise of temperature. The variety of venomous snakes and their related potency toward human being have been well documented. Thus, this may serve as a basic knowledge for any preventive act in the face of snake toxins and their caused physiopathological and clinical effects. In addition, several studies have shown that global warming have caused a change in snake habitat and distribution, thus leading to an increase of overlapped human and snake populations living territories which raise up the risk of envenomation. Globally, more than 20,000 deaths occur every year with a high tendency to increase. Thus, consideration of human risk of envenomation may be fundamental to the effective intervention in epidemiological and clinical scales.

Hottentota gentili is a black scorpion which has been considered as dangerous specie by many authors. However there are no data regarding minimal lethal dose and effects of the scorpion venom till now. We therefore aimed, by the present investigation, to assess on the one hand, the LD50 of H. gentili venom by sublethal injection and the effects on some vital organs, by a histological and a biochemical tools. On the other hand, the possible neurobehavioral impairments, in Swiss mice, 3 h, 6 h and 12 h following envenomation. The LD50 of H. gentili scorpion venom was found to be 0.46 mg/kg by subcutaneous injection route. Venom produced focal fragmentation of myocardial fibers, while lungs showed rupture of the alveolar structure. Intestines showed selective histopathological changes. Concomitantly, there was a significant rise in the serum enzymes levels, as well as hyperkalemia and a high level of plasma albumine and creatine. Proteinuria was also observed. The observed behavioral effects were a hypoactivity in the both experiments 30 min and 3 h after injection. The envenomation produced an increased immobility time only 30 min and 3 h post injection in the tail suspension test (TST).

Ethnopharmacological relevance Thapsia garganica , is a herbal medicine traditionally used as diuretic, emetic and purgative. It is also used as anti-scorpion venom in Morocco; however, its protective effects against scorpion venom remain elusive. Aim of the study The present study was undertaken to evaluate anti-venom activity of T. garganica in vivo through histological and biochemical studies. Materials and methods Methanolic leaves extract of T. garganica was evaluated for anti-venom activity against buthus. occitanus under in vivo conditions. Histopathological and biochemical changes in envenomed and treated mice were also examined. Phytochemical screening was conducted to estimate the major constituents whereas DPPH, β -Carotene–linoleic acid and reducing power assays were performed to evaluate the anti-oxidant activity of T. garganica extract. Results Methanolic leaves extract of T. garganica (2 g/kg) increased the survival time (> 18 h) of mice injected with lethal doses of B. occitanus venom, with remarkable recovery of histology damage. Furthermore T. garganica induced a significant decreased of biochemical markers of kidney, liver and heart function. Phytochemistry screening revealed the presence of phenolic compounds, flavonoids, tannins and steroids/terpenoids, which might explain the bioactivity of the extract. It was also shown that the extract has an exceptionally high antioxidant activity compared to well-known antioxidants used as standards. Conclusion The present study provides strong evidence that support the use of T. garganica as anti-scorpion venom in traditional medicine in Morocco. However, additional studies are required to isolate and identify the metabolites responsible for the activity.