A global review of medically important scorpions and scorpionism

Micaiah Ward and co-workers at Florida State University recently published an extensive review of medically important scorpions, epidemiology and scorpionism. The number of medical important species is raised to 104 (Buthidae: 101, Hemiscorpiidae: 2, Scorpionidae: 1). Of these, 36 species are considered dangerous (causing class II and III symptoms).

It is important to understand that a list like this can not be perfect. The species identification in many sting cases can be missing or wrong. Taxonomy is changing, and a species may turn out to be a species complex with potentially different venom potency (e.g. The Buthus occitanus complex). We should be careful not to label all species not on this list as harmless. A dangerous species may never have stung a human or the sting case was never reported. Also, many stings are dry or a reduced amount of venom is used, causing minor/mild symptoms and by this camouflaging a dangerous species. The article discuss some of these conserns.

 The article also has information about the distribution of medically important species, venom composition and the use of scorpion venom in biomedical research.

Abstract:
Scorpions are an ancient and diverse venomous lineage, with over 2200 currently recognized species. Only a small fraction of scorpion species are considered harmful to humans, but the often life-threatening symptoms caused by a single sting are significant enough to recognize scorpionism as a global health problem. The continued discovery and classification of new species has led to a steady increase in the number of both harmful and harmless scorpion species. The purpose of this review is to update the global record of medically significant scorpion species, assigning each to a recognized sting class based on reported symptoms, and provide the major toxin classes identified in their venoms. We also aim to shed light on the harmless species that, although not a threat to human health, should still be considered medically relevant for their potential in therapeutic development. Included in our review is discussion of the many contributing factors that may cause error in epidemiological estimations and in the determination of medically significant scorpion species, and we provide suggestions for future scorpion research that will aid in overcoming these errors.

Reference:
Ward MJ, Ellsworth SA, Nystrom GS. A global accounting of medically significant scorpions: Epidemiology, major toxins, and comparative resources in harmless counterparts. Toxicon. 2018;151:137-55. [Subscription required for full text]

Thanks to Matt Simon for informing me about this article!

A review on the epidemiology and distribution of medical important scorpions in North America

It is well known that North America and especially Mexico is a hotspot for medical important scorpions. Canada has no dangerous species, while USA has only one (Centruroides sculpturatus Ewing, 1928). Mexico, on the other side, has several species that have great consequences for the public health.

Gonzalez-Santillan & Possani have recently published a review summing up the current knowledge on the distribution and epidemiology of the medical important scorpions of North America. 21 species and one subspecies, all in the genus Centruroides, are identified as medical important, and their distribution is given. The different aspects of scorpionism in North America is also discussed.

Abstract:
Scorpionism is a severe threat to public health in North America. Historically, few species of Centruroides have been considered to be the offending taxa, but we know now that their diversity is greater and our knowledge incomplete. Current distribution maps are inadequate for some species. Epidemiologic studies are sporadic and local, and a complete synthesis for North America is missing. We analyze historical and recent knowledge about the identity, distribution and epidemiology of species of medical importance in North America. PubMed, Google Scholar, the National Collection of Arachnids, and results of recent field work were consulted in the preparation of our analysis. We recognized 21 species and one subspecies of medically important scorpions in need of precise geographical delimitation. All these species are found in Mexico, which is clearly a hotspot for scorpionism. Although mortality has been steadily decreasing, deaths still occur, and morbidity remains high. Mortality is most common at age classes of 0–10 years and>50. Morbidity is highest in age class 15–50 years, including the most economically active segment of the population. The season of the highest incidence of scorpion sting peaks between spring and summer but there appears to be a second, lower peak at the end of the summer. Although the systematics of the genus Centruroides has advanced considerably, our knowledge of its diversity remains fragmentary. There is a disconnection between the actual distribution of the scorpions and the incidence maps constructed from scorpion sting records. Despite a historically robust knowledge of the distribution of wellknown species, most recently described species are known from only a few localities. Some of the epidemiological parameters are consistent among studies reported herein.

Reference:
Gonzalez-Santillan E, Possani LD. North American scorpion species of public health importance with a reappraisal of historical epidemiology. Acta Trop. 2018;187:264-74. [Subscription required for full text]

A review on the scorpionism by the genus Hemiscorpius in Iran

The majority of the literature on scorpionism and medical important scorpions is focused on species on the family Buthidae. But many of the species in the family Hemiscorpiidae can also cause death or serious morbidity. Interestingly, the symptoms of Hemiscorpius Peters, 1861 envenomations are different from the traditional envenomations by buthids. E. g. a sting by the latter will immediately cause pain, while the sting of a Hemiscorpius is usually painless and the patient risk not knowing that a sting has occurred until more serious symptoms occur.

Rouhullah Dehghani and co-workers have now published an interesting review on the scorpionism by Hemiscorpius scorpions in Iran summing up the knowledge on envenomations from these potential dangerous species.

Abstract:
Scorpions are distributed throughout Iran and the genus Hemiscorpius is particularly important in this region. Hemiscorpius lepturus is the most significant species within the genus in the country. Since scorpionism provoked by Hemiscorpius comprises a medical emergency, the present study is focused on this important issue. In order to perform the present work, a review of the medical and health-related literature was carried out in several databases. The current findings indicate that six species of Hemiscorpius are found in 15 states of Iran, mainly in the south and southwest. Deaths caused by stings were reported only for two species. The morphological characteristics and geographical distribution of H. lepturus in Iran, its venom and the toxic compounds, epidemiologic data and clinical manifestations of envenomation as well as treatment for affected people are herein reviewed and described. H. lepturus venom toxicity differs from other Iranian scorpions regarding duration and severity. Scorpionism is an important public health problem in Iran, especially in southwest and south regions and in urban areas. It is more prevalent in children and young people. H. lepturus venom is primarily a cytotoxic agent and has hemolytic, nephrotoxic and to some extent hepatotoxic activity. The use of polyvalent antivenom to prevent scorpion sting symptoms is recommended. A well-planned health education program might be useful in preventing scorpionism.

Reference:
Dehghani R, Kamiabi F, Mohammadi M. Scorpionism by Hemiscorpius spp. in Iran: a review. J Venom Anim Toxins Incl Trop Dis. 2018;24:8. [Open Access]

Family Hemiscorpiidae

Scorpionism in the Shiraz Province in Iran and Hotentotta jayakari as a medical important species

Hossein Sanaei-Zadeh and co-workers published an article on the scorpionism in the Shiraz Province in Iran in late 2017. I refer to the abstract and the article for details, but will mention one interesting and inportant conclusion: The article reports about sting cases involving Hottentotta jayakari (Pocock, 1895) (Buthidae) and concludes that this species should be listed as medical important (at least in Iran).

Abstract:
Background: Scorpionism is a public health problem in some provinces in Iran. The present study aimed to assess the clinical manifestations of scorpion envenomation in Shiraz and determine a clinical severity grading for Iranian scorpion envenomation in order to suggest a treatment guideline for emergency physicians.

Methods: In this analytic retrospective study, all medical charts of patients with scorpion sting admitted in the adult medical toxicology center in Shiraz during July 2012 to July 2016 were assessed. Data regarding the patient's age, gender, sting site, month of envenomation, time of sting, clinical manifestations, vital signs, presence of blood or hemoglobin in urine analysis, duration of admission, color of scorpion, received treatments, and administration of scorpion antivenin were recorded.

Results: The scorpions in Shiraz and its suburban area were classified into two groups: yellow scorpions (Mesobuthus eupeus, Mesobuthus caucasicus, and Compsobuthus matthiesseni) and Hottentotta scorpions (Hottentotta jayakari and Hottentotta zagrosensis). A total of 126 cases of scorpion stings were assessed. About 59% (n=74) were males. The patients aged 8-63 years (mean age, 33.8±11.5 years). About 38.4% (n=48) of the stings occurred during summer. More than 40% of patients (n=51) referred to the emergency department (ED) at night. Localized pain was the most frequent presenting complaint (76.2%). The most frequent general symptom was nausea (6.3%). The most prevalent envenomation site was the lower extremities followed by upper extremities (43.5% and 41.9%, respectively). Based on the clinical severity grading for Iranian scorpion envenomation, 65, 43, and 18 patients (51.6%, 34.1%, and 14.3%) were classified in the grades I, II, and III, respectively. Eighty-one (73%) patients stayed in the ED from 1 to 6 hours, and 30 (27%) patients stayed for >6 hours for observation. Severe localized pain was more prevalent in stings with Hottentotta scorpions than yellow scorpions (P=0.01). The season of envenomation with Hottentotta scorpions was summer in all cases, but envenomation with yellow scorpions was seen throughout the year. All patients received symptomatic treatment, and five were given scorpion antivenin. No death was reported.

Conclusion: Hottentotta jayakari is recommended to be listed among the medically important scorpions in Iran. Moreover, scorpion-stung patients in geographical regions where Hemiscorpius lepturus and Androctonus crassicauda are not prevalent may be treated in outpatient departments. The presented grading system can be used for treating patients with scorpion envenomation.

Reference:
Sanaei-Zadeh H, Marashi SM, Dehghani R. Epidemiological and clinical characteristics of scorpionism in Shiraz (2012-2016); development of a clinical severity grading for Iranian scorpion envenomation. Med J Islam Repub Iran. 2017;31:27. [Open Access]

Dangerous arachnids - Fake news or reality?

I have taken the liberty of stealing the title of an interesting article recently published by Tobias Hauke and Volker Herzig. We all know that our favorite animal group, scorpions, are infamous in the public among laypersons (and sometimes also among scholars), but there aren't that many reviews addressing the facts concerning the medical importance of scorpions and other arachnid groups.

The present paper walks us through the spiders and scorpions of the world and lists taxa with medical significance, all based on scientific evidence. The article also discuss the results in connection with the growing number of arachnids kept as pets. Scorpions of medical importance is one of my main areas of interest, and based on my experience the article's conclusions are valid.

I recommend this article for all that are interested in spider and scorpion envenomations. It will also be interesting for scorpion enthusiasts keeping scorpions as pets, as the article's language is not too advanced and easily understandable for laypersons.

Abstract:
The public perception of spiders and scorpions is skewed towards the potential harm they can inflict in humans, despite recent scientific evidence that arachnid venom components might be useful as bioinsecticides or even human therapeutics. Nevertheless, arachnids are becoming more popular as pets in Europe, America and Asia, raising the question for regulatory agencies in these regions as to whether they need to take measurements to protect their citizens. In order to decide upon the necessary regulatory steps, they first need to determine which arachnids are actually dangerous to humans. This review therefore provides an overview of the current literature on verified bites and stings from spiders and scorpions with the aim of assessing their potential danger for human health. As a guideline, we also provide a list of those arachnid genera that we consider as potentially dangerous, which includes 10 spider and 11 scorpion genera. The arachnid genera classified as dangerous comprise less than a quarter of all extant scorpion species and only 0.5% of all spiders species, with the actual number most likely being much lower than that, as not all species in those genera might turn out to pose an actual threat for humans. In conclusion, we found that only a small percentage of scorpions and a minute percentage of all spiders can be considered as potentially dangerous to humans. While in some countries of origin the high incidence of envenomations by dangerous arachnids can result in a serious problem to the health system, we assessed the risk that the same species pose when kept as pets under controlled maintenance conditions as significantly lower.

Reference:
Hauke TJ, Herzig V. Dangerous arachnids-Fake news or reality? Toxicon. 2017;138:173-83. [Subscription required for full text]

Geographic distribution of scorpion envenomations in the USA

Kang and Brooks recently published a epidemiological study on the geographic distribution of scorpion envenomations in the USA in 2010-2015. Most cases were reported from Arizona (57 168), where the infamous Arizona Bark Scorpion (Centruroides sculpturatus Ewing, 1928) is medical important species. Eight other US states also had scorpion envenomations (ranging from 9659 to 906 cases).

Health consequences of scorpion envenomations are also discussed.

Abstract:
Objectives. To determine the geographic distribution of scorpion envenomations in the United States by zip code, with particular attention to the neurotoxic Centruroides sculpturatus (Arizona bark scorpion), for which an antivenom is available.
Methods. We obtained scorpion exposure cases for 2010 to 2015 from the National Poison Data System. Using geographic information systems software, we mapped total exposures and incidence rates for 9 states that reported more than 100 annual calls. We also mapped cases that reported fasciculations and nystagmus (unique to C. sculpturatus among native scorpions).
Results. The highest exposure incidences occurred in Phoenix (up to 677 per 100 000 population) and Tucson (584), both in Arizona. Elsewhere, high incidences were found in El Paso, Texas (213); Oklahoma City (209) and Tulsa (178), Oklahoma; and Las Vegas, Nevada (170). Fasciculations and nystagmus were reported in Arizona and southeastern Nevada, with small numbers in surrounding states, including Utah.
Conclusions. Scorpion exposures occurred at baseline rates throughout many of the southern states, whereas several states reported effects indicative of Arizona bark scorpion envenomation.

Reference:
Kang AM, Brooks DE. Geographic Distribution of Scorpion Exposures in the United States, 2010-2015. Am J Public Health. 2017;107(12):1958-63. [Subscription required for full text]

Scorpion envenomations in southeastern Ecuador

Juan Roman and co-workers have studied scorpion envenomations in rural locations in the Amazonian province of Morona Santiago, southeastern Ecuador. The severity of scorpion stings in this region is reported and the conclusion is that scorpions are a public health problem, especially for young children.

A phylogenetic analysis of the scorpions involved in serious cases were conducted and revealed that these were caused by a species in the Tityus obscurus group (Buthidae). This group contains species responsible for severe envenomations in other areas of the Amazonian Basin. The Ecuadorian species involved is unknown, and will be described as a new species in a future publication.

Abstract:
Scorpion envenoming by species in the genus Tityus is hereby reported from rural locations in the Amazonian province of Morona Santiago, southeastern Ecuador. Twenty envenoming cases (18 patients under 15 years of age) including one death (a 4-year-old male) were recorded at the Macas General Hospital, Morona Santiago, between January 2015 and December 2016 from the counties of Taisha (n =17), Huamboyo (n= 1), Palora (n =1), and Logroño (n =1). An additional fatality from 2014 (a 3-year-old female from Nayantza, Taisha county) is also reported. Leukocytosis and low serum potassium levels were detected in most patients. We observed a significant negative correlation between leukocytosis and hypokalemia. Scorpions involved in three accidents from Macuma, Taisha County, were identified as genetically related to Tityus obscurus from the Brazilian Amazonian region based on comparison of mitochondrial DNA sequences encoding cytochrome oxidase subunit I. These cases, along with previously reported envenoming from northern Manabí, reinforce the notion that scorpionism is a health hazard for children in Ecuador and emphasizes the need to supply effective antivenoms against local species, which are not currently available. The genetic affinity of the Ecuadorian specimens with T. obscurus may underlay toxinological, clinical, and venom antigenic relationships among Amazonian scorpions that deserves further exploration for designing therapeutic strategies to treat scorpionism in the region.

Reference:
Roman JP, Garcia F, Medina D, Vasquez M, Garcia J, Graham MR, et al. Scorpion envenoming in Morona Santiago, Amazonian Ecuador: Molecular phylogenetics confirms involvement of the Tityus obscurus group. Acta Trop. 2017;178:1-9. [Subscription required for full text]

Thanks to Adolfo Borges and Matthew Graham for both sending me their article!

An update on the medical important scorpions of Mexico

Mexico has a very high diversity of scorpions, but also many medical important species in the genus Centruroides Marx, 1890 (Buthidae). Several of these species have an urban distribution making scorpions a significant health problems in some areas.

Lidia Riano-Umbarila and co-workers have recently published a major study of the medical importance of several Centruroides species based on LD50 tests (a controversial test from a animal welfare and ethics point of view). The article add more knowledge to the list of potential dangerous scorpions species in Mexico (click on the picture to see the species mentioned in this study).

Abstract:
The increment in the number of scorpion envenoming cases in Mexico is mainly associated to the rapid growth of the urban areas, and consequently, to the invasion of natural habitats of these arachnids. On the other hand, there is a great diversity of scorpion species, so it is indispensable to identify those of medical importance, which we now know are many more than the 7-8 previously reported as dangerous to humans. Because different LD50 values have been reported for the venom of the same species, probably due to variations in the experimental conditions used, in this work we determined the LD50 values for the venoms of 13 different species of scorpions using simple but systematic procedures. This information constitutes a referent on the level of toxicity of medically important scorpion species from Mexico and establishes the bases for a more comprehensive assessment of the neutralizing capacity of current and developing antivenoms.

Reference:
Riano-Umbarila L, Rodriguez-Rodriguez ER, Santibanez-Lopez CE, Guereca L, Uribe-Romero SJ, Gomez-Ramirez IV, et al. Updating knowledge on new medically important scorpion species in Mexico. Toxicon. 2017;138:130-7. [Subscription required for full text]

Scorpionism in Jordan

Scorpions are a public health problem in the Middle East with several buthid species in the genera Leiurus Ehrenberg, 1828 and Androctonus Ehrenberg, 1828 causing cases of death and serious morbidity every year.

Zuhair Amr and co-workers have recently published an epidemiological study on scorpion envenomations in Jordan between 2006 and 2012. The main conclusion is that scorpion stings remain a medical problem in Jordan as they are in other countries in the region.

Abstract:

Objective

Scorpionism is an endemic public health problem in Jordan encountered by health providers in all parts of the country. This study updates epidemiological data on scorpion sting encounters in Jordan.

Methods

Data on scorpion sting encounters were obtained from government and military hospitals around the country, and the National Drug and Poison Information Center (NDPIC). P values and 95% confidence intervals (CIs) were calculated using SPSS Professional Statistics Package version 22 (IBM Corp., Armonk, NY) program.

Results

Epidemiological data on 1205 scorpion sting cases reported between 2006 and 2012 are reported. Male to female ratio was 1.18:1, aged 23.3±16 (mean±SD) and 26.4±16.9 years for males and females, respectively. Age groups between 1 to 20 years old constituted 44.6% of the total sting encounters, while adults aged >30 years constituted 30%. Scorpion sting encounters peaked in July (22.5%) and August (23%), with the lowest numbers of recorded cases in February and January (1.6 and 1.9%, respectively). Scorpion stings occurred mostly outdoors (66%). Medical complications associated with scorpion sting cases included fever, difficulty in breathing, drowsiness and dizziness, and numbness, while severe complications include respiratory failure and tachycardia. Hospitalization required 1 to 3 days among admitted patients with no fatalities.

Conclusions

Scorpion stings remain a medical problem in Jordan that requires more attention by health providers. Reporting of scorpion sting cases should be enforced from all healthcare centers throughout the country to better understand the epidemiology and health implications of human encounters.

Reference:
Amr ZS, Al Zou'bi R, Abdo N, Bani Hani R. Scorpion Stings in Jordan: An Update. Wilderness Environ Med. 2017;In Press. [Subscription required for full text]

Scorpion exposures reported in the USA between 2005 and 2015

Kang & Brooks have recently published an epidemiological study on scorpion envenomations in the USA between 2005 and 2015.

Abstract:
Introduction: Previous studies of scorpion envenomation in the United States (US) have focused on Arizona and the bark scorpion, Centruroides sculpturatus. Although many other scorpion species live in the US, information about envenomations in other states is lacking.
Methods: Nationwide scorpion exposures from 2005 to 2015 were analyzed using the National Poison Data System.
Results: Of the 185,402 total exposures, Arizona (68.2%), Texas (10.3%), and Nevada (4.2%) were the top contributors. However, six other southern states reported greater than 100 cases annually, primarily during the warmer months and evening hours. Envenomations occurred most often in a home (97.8%) and were typically managed on-site (90.1%). Pain was the most common effect nationwide (88.7%). Arizona had the highest frequencies of sensory, neuromuscular, and respiratory effects along with higher hospitalization and ICU admission rates, although the latter appeared to drop over the study period. In contrast, local skin effects such as erythema and edema were more common outside of Arizona. Children under 10 years of age in Arizona and Nevada had the highest rates of systemic effects, hospitalization, and ICU admission.
Conclusions: Scorpion envenomations occurred throughout the southern US with similar seasonal and daily variations. Common clinical effects included pain, local edema, and erythema, except in Arizona and Nevada where severe systemic symptoms were more common. Systemic effects correlated with high rates of ICU admissions and intubations, especially in children under 10 years of age. 

Reference:
Kang AM, Brooks DE. Nationwide Scorpion Exposures Reported to US Poison Control Centers from 2005 to 2015. J Med Toxicol. 2017;13(2):158-65. [Subscription required for full text]

Scorpionism in the world - A new systematic review

Happy New Year!

Maria Santos and co-workers recently published a systematic review on the clinical and epidemiological aspects of scorpion envenomations around the world. Scorpionism is an important health problem around the world and especially in some regions with higher incidents and more severe envenomations.Because of this, the present paper is an important contribution to the knowledge of scorpionism.

Abstract:
Objective
Scorpion stings are registered worldwide, but the incidence and the features of the envenomations vary depending on the region. The aim of this review was to summarize the epidemiological, clinical, diagnostic, and therapeutic data worldwide regarding humans stung by scorpions.
Methods
A systematic review of the literature was conducted through the online databases of the Virtual Health Library (VHL), which hosts Medline and the Latin American and Caribbean Center on Health Sciences Informational (LILACS) database. We selected articles published between January 1, 2002 and July 31, 2014.
Results
Scorpion envenomation reports were found throughout the world, mainly in subtropical and tropical regions. The clinical manifestations were sympathetically and parasympathetically mediated, depending on the species of scorpion. Some of the most common severe complications of scorpionism included respiratory distress syndrome, pulmonary edema, cardiac dysfunction, impaired hemostasis, pancreatitis, and multiple organ failure. Scorpion envenomation could be classified as mild, moderate, and severe, and the therapeutic approach was based on the case severity. The treatment comprised 3 components: symptomatic measures, vital functions support, and injection of antivenom. Moreover, the time that elapsed between the sting and administration of the appropriate medical care was extremely important to the patient’s prognosis.
Conclusions
The large number of scorpion stings worldwide is concerning and reaffirms the need for new prevention measures and policies to reduce the incidence, prevalence, morbidity, and mortality rates from these poisonous arachnids.

Reference:
Santos MS, Silva CG, Neto BS, Grangeiro Junior CR, Lopes VH, Teixeira Junior AG, et al. Clinical and Epidemiological Aspects of Scorpionism in the World: A Systematic Review. Wilderness Environ Med. 2016;27(4):504-18. [Subscription required for full text]

Scorpion of medical importance and their identification

Scorpions are quite a diverse group with 2301 species around the world (pr 01.08.16). Even though infamous, most scorpions are quite harmless and perhaps around 50 species can cause death or serious morbidity in humans.

The challenge in scorpion sting cases is the correct identification of the scorpion involved. Incomplete identification or misidentification happens, and in some cases this can cause inefficacy in the treatment of the symptoms caused by a dangerous species (or even worsen the outcome).

In a recent article, Wilson Lourenco attempts to explain and elucidate a number of common problems in scorpion identification, taxonomy, distribution and biogeography. The article is written in a language making it possible for non-zoologists to understand and in this way increasing the knowledge about scorpions for both professionals and amateurs. Hopefully, this will also be a tool for those treating scorpion sting patients.

Abstract:
The aim of this contribution is to bring general information on the classification and in particular on the specific identification of scorpion species dangerous to humans. Several generic groups are taken into consideration, but the Neotropical genus Tityus C. L. Koch, 1836 is used as a major example. The content of this paper is mostly addressed to non-specialists whose research embraces scorpions in several fields such as venom toxins and public health. Although efforts have been made in the last 20 years to create better links between ‘true scorpion experts’ and non-specialists who use scorpions in their research, such exchanges had never led to a consensus among those different branches of biological and medical research. Consequently, many cases of species misidentification and even more serious errors concerning scorpion classification/identification are often present in the specialized literature. In conclusion, it is suggested here that the frequent cases of misidentification observed in several reports may induce mistakes in the final interpretation of results, leading only to more inefficacity in the treatment of problems caused by infamous scorpion species.

Reference:
Lourenco WR. Scorpion incidents, misidentification cases and possible implications for the final interpretation of results. J Venom Anim Toxins Incl Trop Dis. 2016;22:1. [Open Access]

First documented envenomation from the medical important species Leiurus abdullahbayrami from Turkey

Michael Seiter and co-workers have recently published a case report involving the sting of the recently described species Leiurus abdullahbayrami Yağmur, Koç & Kunt, 2009 (Buthidae) from Turkey.This report is the first documented envenomation from this potential dangerous species.

Abstract:
Scorpion stings are very common in Turkey. Nevertheless, they are not well documented in the literature and were never reported for the recently described scorpion species Leiurus abdullahbayrami Yağmur, Koç & Kunt, 2009. Here, we report a case in which a 30-year-old male was stung by a L. abdullahbayrami scorpion in the field. He was directly brought to the emergency department of the local hospital. The symptomatic process was observed and documented. In this case, no antivenom was necessary; we hypothesize that the scorpion has used most of its venom in a previous incident (explained in further detail below) and was therefore not able to inject a normal dosage.

Reference:
Seiter M, Koc H, Ullrich A, Yagmur EA. The case history of a toxic sting of a Leiurus abdullahbayrami scorpion in Turkey.  Arachnologische Mitteilungen. 2016;51:64-6. [Open Access]

Thanks to Alex Ullrich for sending me a copy of their article!

An update on scorpionism in Ecuador

Previously it has been assumed that Ecuadorian scorpions have had low public health importance, but a study published by Adolfo Borges and co-workers late last year present several severe and fatal sting cases from Ecuador. The species involved in the serious cases was Tityus asthenes Pocock, 1893 (Buthidae).

Abstract:
The presence in rural areas of western Ecuador of scorpions in the genus Tityus capable of producing pediatric mortality is hereby evidenced. The medical significance of scorpions in Ecuador has been underestimated partly because of the clinically unimportant stings delivered by Centruroides margaritatus and Teuthraustes atramentarius, which have venom with low toxicity to vertebrates. Five intradomiciliary cases of scorpion envenoming in victims aged between 1.9 and 16 years old, including one fatality, are reported from rural settings in forest areas of Chone (n ¼ 2) and Flavio Alfaro (n ¼ 3) counties, northern Manabí province, western Ecuador. Three cases were graded as Class II (moderate) and two in Class III (severe) envenoming. Manifestations showed characteristic autonomic nervous system hyper-stimulation and the fatality (a 1.9-year-old boy from Flavio Alfaro) was due to cardiorespiratory failure. Marked leukocytosis in four of the cases (21,800e31,800 cells/mm3), with notable neutrophilia (58e82%), suggests induction of a venom-mediated systemic inflammatory response-like syndrome. Specimens responsible for cases in Flavio Alfaro County, including the fatality, were classified as Tityus asthenes Pocock, accountable for severe scorpionism in Colombia. These findings demand implementation of control and therapeutic measures in affected areas in Ecuador, including evaluation of available scorpion antivenoms.

Reference:
Borges A, Morales M, Loor W, Delgado M. Scorpionism in Ecuador: First report of severe and fatal envenoming cases from northern Manabí by Tityus asthenes Pocock. Toxicon. 2015;105:56-61. [Subscription required for full text]

Thanks a lot to Dr. Borges for sending me his article!

A major review on Mexican scorpions, their biology, distribution and medical importance

Carlos Santibáñez-López and co-workers have recently published an extensive review article summing up the current knowledge on Mexican scorpions. The article covers taxonomy, distribution, biology, venom and medical importance, and is an important work for those interested in the diverse and interesting scorpion fauna of Mexico.

Abstract:
Scorpions are among the oldest terrestrial arthropods, which are distributed worldwide, except for Antarctica and some Pacific islands. Scorpion envenomation represents a public health problem in several parts of the world. Mexico harbors the highest diversity of scorpions in the world, including some of the world’s medically important scorpion species. The systematics and diversity of Mexican scorpion fauna has not been revised in the past decade; and due to recent and exhaustive collection efforts as part of different ongoing major revisionary systematic projects, our understanding of this diversity has changed compared with previous assessments. Given the presence of several medically important scorpion species, the study of their venom in the country is also important. In the present contribution, the diversity of scorpion species in Mexico is revised and updated based on several new systematic contributions; 281 different species are recorded. Commentaries on recent venomic, ecological and behavioral studies of Mexican scorpions are also provided. A list containing the most important peptides identified from 16 different species is included. A graphical representation of the different types of components found in these venoms is also revised. A map with hotspots showing the current knowledge on scorpion distribution and areas explored in Mexico is also provided.

Reference:
Santibanez-Lopez CE, Francke OF, Ureta C, Possani LD. Scorpions from Mexico: From Species Diversity to Venom Complexity. Toxins (Basel). 2015;8(1). [Open Access]

Thanks to Dr. Santibáñez-López and Carlos Turiel for both sending me this paper!

First report of death due to Hemiscorpius acanthocercus envenomation in Iran

It has been well known for a long time that the non-buthid species Hemiscorpius lepturus Peters, 1861 (Hemiscorpiidae) is dangerous and have caused serious morbidity and even death. Now, Mehran Shahi and co-workers report of the death of a 15 year male after being stung by a Hemiscorpius acanthocercus Monod & Lourenço, 2005. This is the first documented case involving serious scorpionism in this species, even though it has been assumed that the species in this genus may all be dangerous.

What makes the Hemiscorpius sting so special is that there is no pain or special symptoms involved short after the sting. In the present case, the patient did not seek medical help until 12 days after the envenomation and then he had developed severe complications. Other studies also reports that deaths due to Hemiscorpius stings are connected with delayed medical care due to none or mild symptoms in the days following the sting.

Hemiscorpius occurs throughout Asia (Iran, Iraq, Oman, Pakistan, Saudi Arabia, Yemen, and the United Arab Emirates) and Africa (Eritrea, Somalia, and Egypt) and it is clear that genus may be a public health risk in some areas.

Abstract:
Scorpion stings are significant causes of death in the western and southern regions of Iran. To date, reports have indicated that the H. lepturus species is the main cause of mortality due to scorpion stings. One of the species that belongs to this genus is Hemiscorpius acanthocercus (H. acanthocercus). This scorpion's venom is cytotoxic, and it causes pathological changes in the blood and can cause severe damage to the kidneys. The pain of Hemiscorpius’ sting is mild and asymptomatic in the early hours. Delays in the treatment of these victims can cause hemolysis, hematuria, kidney failure, and even death. In this paper, we report the first known death due to an H. acanthocercus’ sting in Iran.

Reference:
Shahi M, Rafinejad J, Az-Khosravi L, Moosavy SH. First report of death due to Hemiscorpius acanthocercus envenomation in Iran: Case report. Electronic physician. 2015 Sep;7(5):1234-8. [Open Access]

An updated checklist of the scorpion fauna of Ecuador and a review on their medical importance

Gabriel Brito and Adolfo Borges have recently published an interesting article on the scorpion fauna of Ecuador. Ecuador is a hotspot for scorpion biodiversity and the authors present an updated checklist of the scorpion fauna of this country. Details of distribution and habitat are also presented.

The article also discuss the medical importance of the scorpion fauna of Ecuador.

Abstract:
Ecuador harbors one of the most diverse Neotropical scorpion faunas, hereby updated to 47 species contained within eight genera and five families, which inhabits the “Costa” (n = 17), “Sierra” (n = 34), “Oriente” (n = 16) and “Insular” (n = 2) biogeographical regions, corresponding to the western coastal, Andean, Amazonian, and the Galápagos archipelago regions, respectively. The genus Tityus Koch, in the family Buthidae, responsible for severe/fatal accidents elsewhere in northern South America and the Amazonia, is represented in Ecuador by 16 species, including T. asthenes, which has caused fatalities in Colombia and Panama, and now in the Ecuadorian provinces of Morona Santiago and Sucumbíos. Underestimation of the medical significance of scorpion envenoming in Ecuador arises from the fact that Centruroides margaritatus (Gervais) (family Buthidae) and Teuthraustes atramentarius Simon (family Chactidae), whose venoms show low toxicity towards vertebrates, frequently envenom humans in the highly populated Guayas and Pichincha provinces. This work also updates the local scorpion faunal endemicity (74.5 %) and its geographical distribution, and reviews available medical/biochemical information on each species in the light of the increasing problem of scorpionism in the country. A proposal is hereby put forward to classify the Ecuadorian scorpions based on their potential medical importance.

Reference:
Brito G, Borges A. A checklist of the scorpions of Ecuador (Arachnida: Scorpiones), with notes on the distribution and medical significance of some species. J Venom Anim Toxins Incl Trop Dis. 2015;21:23. [Open Access]

Thanks to Dr. Borges for sending me this article!

Medical important scorpions in Western Brazilian Amazon

It is well known that scorpions are a major public health problem in many regions of Brazil, but inside Brazil this problem have partly been neglected. But with with an increasing number of sting registrations every year in the country and 78,091 cases reported in 2013, it is important with quality research identifying dangerous species and risk factors.

Amanda M. Queiroz and co-workers have now published a case-controlled study analysis the severity of scorpion stings in Western Brazilian Amazon. Dangerous species are Tityus obscurus (Gervais, 1843), T. metuendus Pocock, 1897 and T. silvestris Pocock, 1897 (family Buthidae). Six deaths were registered and the main conclusion of the study is that scorpion stings showed a extensive distribution in the Western Brazilian Amazon and represent a potential occupational health problem for rural populations in this region.

Abstract:

Reference:
Queiroz AM, Sampaio VS, Mendonca I, Fe NF, Sachett J, Ferreira LC, et al. Severity of Scorpion Stings in the Western Brazilian Amazon: A Case-Control Study. PLoS One. 2015;10(6):e0128819. [Open Access]

A major reference book on scorpion venoms and scorpionism

Last Fall a major reference book on scorpion venoms and scorpionism around the world was published. I haven't read this book yet, but I will later and I plan to post information about the most interesting chapters in the blog. Unfortunately, the book is very expensive to purchase (unless your university has a Springer ebook subscription).

Information about the book Scorpion Venoms from Springer

The publisher has the following information about the content of the book:

• Provides accessible yet in-depth entries on the state of the art of scorpion venom research
• Introduces scorpion biology and ecology and covers studies of their venom and “anti-venoms”
• Contains species-centered overviews and examines the scorpion toxins
• Explores the complex interactions of scorpion venoms with the immune system

Scorpions have fascinated humans for a long time, first and foremost because of the harm the sting of a few species could cause but also due to their unique natural history and for the many biologically active compounds found in their venoms. This volume of the Toxinology handbook series covers all those aspects. The subjects are divided into seven sections starting with an introduction to the general aspects of scorpion biology and ecology, followed by the description of the “envenomation” pathophysiology, pharmacokinetics, and pharmacodynamics of venoms and their complex interactions with the immune system. The future of anti-scorpion venom therapy is then covered in two chapters dedicated to alternatives to the century-old techniques currently used to produce “anti-venoms”. The next section presents a world tour of “scorpionism” and dangerous scorpion species and their impact on human health. It is worth remembering that envenomation due to scorpion stings is a substantial health hazard in Asian, Middle Eastern, African, and Latin American countries, with over one million people stung by scorpions every year, resulting in more than 3,000 deaths. Species-centered overviews of “scorpion venoms” are presented in the next section, after which a section details the two main types of “scorpion toxins”. The last section covers high-throughput transcriptome and proteome screenings now known as “venomics”.

Reference:
Gopalakrishnakone P, Possani LDF, Schwartz E, Rodríguez de la Vega RC, editors. Scorpion Venoms. Dordrecht: Springer; 2014. [Subscritpion is required for access to the full text of the book]

Thanks to Dr. Adolfo Borges for sending me a copy of his chapter in the book and thereby notifying me about this book!

A new review on scorpion envenomation

Pathophysiological and clinical effects of systemic scorpion envenomation. Isbister & Bawaskar/New England Journal of Medicine, 2014 (C).

With more than one million cases of scorpion envenomation each year worldwide with substantial morbidity and even death in children, scorpions pose a health challenge in many countries. Geoffrey Isbister and Himmatrao Bawaskar have recently published a updated review on the effects of scorpion envenomation and the current treatment knowledge in the top medical journal New England Journal of Medicine.

This article is essential for health personnel dealing with scorpion envenomation patients, scorpion researchers and others interested in scorpions as it sums up symptoms, pathophysiology, clinical manifestations and treatment for scorpion envenomations.

Abstract:
Scorpion stings and envenomation are of clinical importance worldwide, and although most stings cause only local effects, severe envenomation that causes either excessive autonomic activity and cardiovascular toxic effects or neuromuscular toxic effects results in illness and, in the case of children, in death. The specific treatment is the administration of antivenom combined with symptomatic and supportive treatment, including prazosin and dobutamine in patients with cardiovascular toxic effects and benzodiazepines when there is neuromuscular involvement.

Reference:
Isbister GK, Bawaskar HS. Scorpion Envenomation. N Engl J Med. 2014;371(5):457-63. [Subscription required for full text]