Aranhas de interesse médico no Brasil / Spiders of medical interest in Brazil

O documento apresenta informações sobre aranhas de importância médica no Brasil. Descreve a estrutura externa das aranhas e destaca três gêneros de importância em saúde pública: aranha-marrom (Loxosceles), aranha-armadeira ou macaca (Phoneutria) e viúva-negra (Latrodectus). Traz imagens dessas espécies e lista sinais, sintomas e tratamento para acidentes com elas. Apresenta dados de série histórica de acidentes por aranhas no Brasil e Tocantins entre 2000-2022. Por fim, traz recomendações sobre prevenção e primeiro atendimento para acidentes com aranhas.

The document provides information on medically significant spiders in Brazil. It describes the external structure of spiders and highlights three genera of public health importance: brown recluse spider (Loxosceles), wandering spider or macaque spider (Phoneutria), and black widow spider (Latrodectus). It includes images of these species and lists signs, symptoms, and treatment for accidents involving them. It presents historical data on spider-related accidents in Brazil and Tocantins between 2000-2022. Finally, it provides recommendations for prevention and initial first aid for spider bites.

El documento proporciona información sobre arañas de importancia médica en Brasil. Describe la estructura externa de las arañas y destaca tres géneros de importancia para la salud pública: la araña de rincón (Loxosceles), la araña errante o araña mono (Phoneutria) y la viuda negra (Latrodectus). Incluye imágenes de estas especies y enumera los signos, síntomas y tratamiento para accidentes con ellas. Presenta datos históricos sobre accidentes relacionados con arañas en Brasil y Tocantins entre 2000 y 2022. Por último, proporciona recomendaciones para la prevención y la atención de primeros auxilios en caso de picaduras de araña.

Reversible Myocarditis Following Black Widow Spider (Latrodectus spp.) Bite in Egypt: A case report.

Black widow spiders (BWSs) are poisonous spiders of the Arthropoda phylum that live in the Mediterranean region. The effects of BWS bites ranges from local damage to systemic manifestations including paresthesia, stiffness, abdominal cramps, nausea, vomiting, headache, anxiety, hypertension and tachycardia. However, cardiac involvement following a BWS bite is uncommon. We report a 35-year-old male patient who presented to a tertiary hospital in Menoufia, Egypt, in 2019 and developed acute pulmonary oedema with electrocardiogram (ECG) changes that showed ST elevation in leads I and aVL with reciprocal ST segment depression in infero-lateral leads with elevated cardiac biomarkers. Echocardiography showed regional wall motion abnormalities with an impaired ejection fraction of 42%. The condition was reversible after one week of supportive treatment and the patient was discharged from the hospital with normal electrocardiogram, ejection fraction and negative cardiac markers. A routine cardiac evaluation, serial ECG, serial cardiac markers and echocardiography should be considered for any patient exposed to a BWS bite for detection of any potentially fatal cardiac abnormalities.

Case Report: Soldier With Latrodectism After Black Widow Spider Bite During a Field Training Exercise.

Latrodectism from black widow spider (BWS) bites is rare in the United States. Latrodectism is a severe systemic manifestation of the envenomation that includes severe abdominal pain mimicking acute surgical abdomen and, in rare cases, could lead to acute myocarditis and rhabdomyolysis. The BWS typically inhabits dark, low-lying areas such as woodpiles, tree stumps, outdoor storage, outdoor furniture, outdoor toilets, and rock piles and is most active during warm weather months. Military service members often participate in field training exercises during warm weather in wooded areas littered with woodpiles and tree stumps; therefore, they are at an increased risk for bites by arachnids. We report the case of a 26-year-old active duty male soldier evacuated from field training with latrodectism and possible envenomation-induced myocarditis after a suspected BWS bite.

Coexistence of Rhabdomyolysis, Myocarditis and Arrhythmia after Spider Bite: A Case Report.

BACKGROUND: Rhabdomyolysis after spider bite has been reported in a small number of patients, and myocarditis in even fewer. However, arrhythmia associated with latrodectism in children has not been described in the literature to date. CASE SUMMARY: A girl presented approximately 4.5 h after being bitten on the left ankle by a black spider. Two unifocal premature ventricular contractions (PVCs) were observed on the electrocardiogram. In laboratory tests, creatine kinase was elevated. On day 2, levels of troponin, pro-brain and natriuretic peptide were elevated. Electrocardiogram revealed inverted and biphasic T waves. Echocardiography revealed mild left ventricular dilation, mitral and aortic valve regurgitation. Holter electrocardiogram showed PVCs. Her laboratory and echocardiography findings completely normalized after discharge, and no arrhythmia was observed on the Holter electrocardiogram during outpatient follow-up. CONCLUSION: Although spider bites are uncommon, they can cause serious systemic effects. These patients should be evaluated for arrhythmia, rhabdomyolysis and myocarditis.

Rarely, spider bites can cause serious systemic effects, severe morbidity and death. In a small number of patients, spider envenomation causes rhabdomyolysis and myocarditis. In the present case, the elevated troponin and pro-brain natriuretic peptide levels and electrocardiogram/echocardiography findings were consistent with myocarditis, and an increase in creatinine kinase level indicated rhabdomyolysis. In addition, the electrocardiogram and Holter electrocardiogram revealed unifocal premature ventricular contraction. To our knowledge, arrhythmia due to Latrodectus spider bite has not been described in children to date. In addition, this case demonstrates the coexistence of two serious systemic effects, rhabdomyolysis and myocarditis, with full recovery after appropriate treatment.

First Record of Black Widow Spider Bite Latrodectus cinctus (Araneae: Theridiidae) From Iran.

The genus Latrodectus contains the most medically important spiders around the world. This study describes the first case of Latrodectus cinctus Blackwall, 1865 bite and clinical treatment from Iran. Also, it is the first collection report from the southeast of the country that can enhance prior knowledge on the geographical distribution of this species. We describe a 42-year-old female patient with neurological pain caused by the spider bite. Also, a summary of the entomological survey and morphological identification of the collected species from the patient's house is presented.

Bites by the noble false widow spider Steatoda nobilis can induce Latrodectus-like symptoms and vector-borne bacterial infections with implications for public health: a case series.

CONTEXT: In recent years, the Noble false widow spider Steatoda nobilis (Thorell, 1875) has expanded its range globally and may represent a potential threat to native ecosystems and public health. Increasing numbers in synanthropic habitats have led to more human encounters and envenomations. Steatoda nobilis bites were previously classed as medically significant with similarities to bites from true black widows of the genus Latrodectus but deemed milder in onset, with symptoms generally ranging from mild to moderate. CASE DETAILS: In this manuscript we present 16 new cases of S. nobilis envenomations bringing the total number of confirmed cases reported in the literature to 24. We report new symptoms and provide discussion on the contributing factors to pathology following bites by S. nobilis. DISCUSSION: We report a range of pathologies including necrosis, Latrodectus-like envenomation symptoms that include debilitating pain, tremors, fatigue, nausea, hypotension, and vectored bacterial infections including cellulitis and dermatitis. Symptoms ranged from mild to severe, requiring hospitalisation in some cases.

Silently Suffering: A Pediatric Black Widow Spider Envenomation.

BACKGROUND: Black widow spiders are distributed worldwide and, although rarely fatal, account for significant morbidity. Diagnosis can be challenging, and children are at risk of increased morbidity due to their small size. CASE REPORT: We present a case of a 3-year-old boy who was brought to our emergency department because of sudden ear pain followed by labored breathing, abdominal pain, refusal or inability to speak, and grunting respirations. A black widow spider bite was suspected based on additional history obtained, and the spider was found in his helmet, confirming the diagnosis. The patient had progressive respiratory distress and somnolence and was intubated and transferred to a local pediatric intensive care unit. Antivenom was not initially available and eventually declined by the family. The child received supportive care and recovered after several days. Why Should an Emergency Physician Be Aware of This? This case illustrates the potentially deadly effects a black widow envenomation could cause in a child, and that bite location can affect the constellation of symptoms. It is a reminder that toxins, including that of the black widow spider, should be on the differential for acute abdominal pain, especially with autonomic features.

A case of pediatric northern black widow spider (Latrodectus variolus) bite in New York, USA.

Black widow spiders (Latrodectus spp.) are generally perceived as inhabiting southern or western United States. However, some species, such as the northern black widow, Latrodectus variolus, are also found in more temperate regions of USA and adjacent Canada. This species also appears to expand its range northward with the climate change increasing the risk of human encounters. To our knowledge, this is the first case report of a pediatric envenomation from a northern black widow bite in northeastern US. Medical practitioners often fail to recognize the signs and symptoms of latrodectism delaying effective treatment. Even in more northern locales, healthcare workers should take black widow spider envenomation under consideration in the differential diagnosis particularly with suspected exposure.

A Review of Black Widow (Araneae: Theridiidae) Envenomation, Epidemiology, and Antivenom Utilization in Canada.

Two species of black widow spider (BWS-Latrodectus hesperus Chamberlin & Ivie and Latrodectus variolus Walckenaer) naturally occur in Canada and are capable of causing deleterious envenomation to humans. No Canadian literature exists on the frequency of envenomations by these species or the use of antivenom in the treatment of those patients. A review of primary Canadian arachnology data was undertaken to identify BWS populations. A retrospective review of the Health Canada Special Access Program records generated epidemiology and the utilization of antivenom for BWS envenomations in Canada. The geographical distribution of BWS species is limited to along the southern Canadian border. From January 2009 to December 2015, there were five BWS envenomations that required treatment with antivenom and all cases occurred in British Columbia. An average patient age of 41 yr ± 21 SD (range 7-59) was observed, along with three of the five patients being female. The average number of vials used for treatment was 2 ± 1 SD (range 1-3). BWS Antivenin was also obtained by facilities in Alberta, Ontario, and Nova Scotia, but not used in any of these jurisdictions. Further investigation is necessary to determine the annual incidence of BWS envenomations and if treatment with BWS antivenin is required.

A loxoscelism case received therapeutic apheresis and hyperbaric oxygen therapy.

Loxosceles reclusa (L.reclusa) is known to bite humans, and its venom includes several enzymes that cause clinical symptoms. Loxoscelism, a condition due to being bitten by Loxosceles spiders, commonly known as recluses, can involve a range of clinical conditions, from local cutaneous lesions to severe systemic involvement. The diagnosis of loxoscelism is usually made by anamnesis and clinical findings. Magnetic resonance imaging is recommended for patients at high risk of necrotizing fasciitis. Treatment modalities are still controversial and there is no standardized treatment approach. Reported here, our case of loxoscelism involved a 24-year-old man presenting with a Loxosceles spider bite, dermonecrotic lesion, vomiting, diarrhea, acute renal injury, and rhabdomyolysis, who was successfully treated with hyperbaric oxygen therapy, therapeutic apheresis, hemodialysis, wound debridement, and cutaneous autografting. Early diagnosis and multidisciplinary approach can be life-saving in spider bites that can cause systemic involvement. Loxoscelism should be considered in patients with skin necrosis, acute renal injury, and rhabdomyolysis.

Latrodectus geometricus (Aranea: Theridiidae) envenoming: Rapid resolution of symptoms following F(ab')2 antivenom therapy.

The Brown Widow spider (Latrodectus geometricus) is an invasive species whose geographic range has been expanding worldwide. It is a relative species of the Black Widow and Red-backed spiders of the genus Latrodectus. Despite its broad geographic distribution cases of Brown Widow envenomation have rarely been documented. The venom of L. geometricus is similar to the venom of L. mactans with the primary venom component being alpha-latrotoxin, and consequent envenoming by L. geometricus to humans has resulted in symptoms similar to those reported for other Latrodectus spp. Specific FDA approved Latrodectus antivenom (IgG) available in North America has been effectively used in treating venom-induced symptoms following L. mactans envenoming. The patient reported here involved a confirmed L. geometricus envenoming who was efficaciously treated with an alternately available F(ab')2 antivenom from Mexico.

Along came a spider: Medicine's most famous spider eponyms.

Spiders have long been admired for the beauty of their webs. They are celebrated in popular culture as well as in medical eponyms. This contribution provides the historical background for three spider-related eponyms: nevus araneus (spider angioma), arachnodactyly, and the arachnoid mater. Nevus araneus was first named and described by Sir Erasmus Wilson in 1842. Arachnodactyly was described in 1896 by Antoine Marfan using the term pattes d'araignée, which means spider legs. In 1902, Emile Charles Achard proposed the term arachnodactyly for this clinical finding. The arachnoid mater had been named in 1699 by Frederik Ruysch. The clinical management of spider bites from the only two dangerous venomous spiders within the United States, the black widow spider (Latrodectus mactans) and the brown recluse spider (Loxosceles reclusa), is reviewed.

National Estimates of Noncanine Bite and Sting Injuries Treated in US Hospital Emergency Departments, 2011-2015.

OBJECTIVES: Injuries resulting from contact with animals are a significant public health concern. This study quantifies and updates nonfatal bite and sting injuries by noncanine sources using the most recent data available (2011-2015) from the National Electronic Injury Surveillance System-All Injury Program with the purpose of using these updates to better understand public health consequences and prevention techniques. Increased rates of bites and stings can be expected in this study's time frame, possibly caused by the increasing human population expanding into animal territories, as well as changes in animal geographic distribution and pet ownership. METHODS: The National Electronic Injury Surveillance System-All Injury Program is an ongoing nationally representative surveillance system used to monitor all types and causes of injuries treated in US hospital emergency departments (EDs). Cases were coded by trained hospital coders using information from medical records on animal sources of bite and sting injuries being treated. Data from 2011-2015 were weighted to produce national annualized estimates, percentages, and rates based on the US population. RESULTS: An estimated 1.17 million people visited EDs for noncanine bite and sting injuries annually. This translates to a rate of 371.3/100,000 people. Insects accounted for 71.0% of noncanine bite and sting injuries, followed by arachnids (19.2%) and mammals (7.8%). The estimated annual total lifetime medical and work cost of unintentional noncanine injuries was $5,755,581,000. CONCLUSIONS: Various sources of bite and sting injuries had an outsized effect on injury rates and identify potential areas of focus for education and prevention programs to reduce the burden of these injuries on health and healthcare costs. The study describes the diversity of animal exposures based on a national sample of EDs. Noncanine bite and sting injuries significantly affect public health and healthcare resources. Priorities can be focused on animal sources with the most impact on bite and sting injury rates, healthcare costs, and disease burden.

Latrodectism in Italy: First report of successful treatment of L. tredecimguttatus envenomation using L. mactans antivenom from North America.

INTRODUCTION: Latrodectism is a rare, but potentially severe, clinical syndrome caused by spider of the genus Latrodectus. L. tredecimguttatus is widespread in Italy and its bite cause the injection of α-latrotoxin that cause depletion of acetylcholine at motor nerve endings and release of catecholamines at adrenergic nerve endings. We describe the first clinical case of L. tredecimguttatus poisoning successfully treated with L. mactans antivenom from North America. CASE REPORT: A healthy 60-year-old patient was admitted to the emergency department after unknown insect sting or arachnid/snake bite. In the early morning, the patient was working in the countryside when he felt a sting-like pain in the medial area of the right lower leg, associated with an intense burning sensation. An hour later he developed agitation, hoarseness, sweating, abdominal distress and intense pain in his right leg. In the emergency room vital signs showed a hypertensive crisis, tachycardia and peripheral oxygen desaturation. ECG was normal and ABE showed mixed acid-base disorder. Blood tests showed leukocytosis with neutrophilia, high levels of myoglobin, with normal coagulation and normal plasmatic cholinesterase. Neck, thorax and abdomen CT scan, with and without contrast medium, was negative. Four hours after admission hypertension worsened with board like rigid abdomen and onset of fasciculations, tremors, miosis and intense regional sweating. The definitive diagnosis of poisoning by L tredecimguttatus was based on the clinical picture. Within short time the antidote was provided by the Poison Centre and administered. A marked improvement of the symptomatology was noted after 30 minutes, and 1 hour later all symptoms were under control. The patient was discharged after 2 days. CONCLUSIONS: The clinical presentation of a patient suffering from latrodectism places the clinician in front of a challenging differential diagnosis. Following the suspicion, the first-line doctor is invited to discuss the case with a toxicologist, in order to confirm or exclude the diagnosis and implement all therapeutic measures. In our clinical case, the absence of organic lesions, laboratory tests not suggestive for other causes, and the presence of typical clinical feature suggested the diagnosis of L tredecimguttatus poisoning. This hypothesis was then supported by the close temporal relation between antivenom administration and symptoms improvement. With this case, we report the first use of L mactans antivenom from North America to treat L.tredecimguttatus poisoning and we confirm its effectiveness in counteracting latrodectism caused by this spider.

The Efficacy of Antivenin Latrodectus (Black Widow) Equine Immune F(ab')2 Versus Placebo in the Treatment of Latrodectism: A Randomized, Double-Blind, Placebo-Controlled, Clinical Trial.

STUDY OBJECTIVE: The antivenom currently available for treatment of systemic black widow envenomation (latrodectism) is composed of equine whole immunoglobin. Although considered effective, it has been associated with anaphylaxis and 2 reported fatalities. We test the efficacy and safety of new equine antivenom composed of purified F(ab')2 antibody fragments. METHODS: A randomized, double-blind, placebo-controlled trial was conducted at 16 sites across the United States. Subjects aged 10 years or older with moderate to severe pain because of black widow spider envenomation received F(ab')2 antivenom or placebo. The primary outcome measure was treatment failure, which was defined as failure to achieve and maintain clinically significant reduction in pain for 48 hours posttreatment. Secondary measures of pain intensity differences and summed pain intensity difference were computed. Adverse events were recorded. RESULTS: Sixty patients were treated (29 antivenom and 31 placebo). The mean age was 39 years and 68% were male. There were 15 treatment failures in the antivenom group and 24 in the placebo group (P=.019). Differences in pain intensity difference between groups were lower at each postbaseline point, and the mean summed pain intensity difference was greater for the antivenom group (difference 2,133; 95% confidence interval 177 to 4,090). No deaths or serious drug-related adverse events were detected. CONCLUSION: The F(ab')2 antivenom met the predefined primary outcome of reduced treatment failures. Secondary outcomes of pain intensity difference and summed pain intensity difference also supported efficacy. The rate of symptom improvement in the placebo group was higher than expected, which may be related to enrollment criteria or placebo effect.

Latrodectismo en una paciente pediátrica / Latrodectism in a pediatric patient

Introducción: el conjunto de síntomas y signos provocados por la mordedura de la araña Latrodectus mactans, llamada viuda negra, se conoce como latrodectismo. En Cuba son escasos los estudios realizados y publicados al respecto. Solo se han reportado cuatro casos en adultos en un artículo del año 1998 y uno en un adolescente en el año 2006, todos de la provincia Ciego de Ávila.Objetivo: presentar el caso de una paciente pediátrica envenenada por la mordedura de una araña viuda negra, de interés por ser infrecuente.Presentación del caso: paciente femenina, de ocho años de edad, color de la piel blanco, residente en una zona suburbana del poblado Gaspar, municipio Baraguá, provincia Ciego de Ávila. Fue mordida por una araña pequeña, de color negro. Presentó mareos, dolor en el abdomen y el muslo izquierdo, y marcada palidez. Fue hospitalizada y posteriormente manifestó dolores en ambos miembros inferiores, entumecimiento, sudoración en pies y manos, e insomnio. Este cuadro clínico se mantuvo varios días. Los exámenes complementarios resultaron normales. En el electrocardiograma se detectó taquicardia sinusal. El tratamiento consistió en gluconato cálcico al 10 por ciento en perfusión endovenosa, sedación y alivio del dolor.Conclusiones: los médicos de las áreas rurales o suburbanas deben estar prevenidos ante la eventualidad de recibir pacientes con latrodectismo, debido al cuadro clínico inespecífico, que dificulta el diagnóstico. Sería conveniente la realización en Cuba de estudios toxicológicos acerca de Latrodectus mactans, por el problema de salud que entrañan su toxicidad y el no contar con el antídoto específico(AU)

Introduction: the set of symptoms and signs caused by the bite of the spider Latrodectus mactans, called black widow, is known as latrodectism. In Cuba there are few studies carried out and published in this regard. Only four cases have been reported in adults in an article of the year 1998 and one in a teenager in 2006, all of the province of Ciego de Ávila.Objective: to present the case of a pediatric patient poisoned by the bite of a black widow spider, of interest because it is infrequent.Case presentation: female patient, eight years old, white skin, resident in a suburban area of Gaspar village, Baraguá municipality, Ciego de Ávila province. She was bitten by a small, black spider. He presented dizziness, pain in the abdomen and left thigh, and marked pallor. She was hospitalized and later manifested pain in both lower limbs, numbness, sweating in hands and feet, and insomnia. This clinical picture remained several days. Complementary tests were normal. Electrocardiogram detected sinus tachycardia. The treatment consisted of 10 percent calcium gluconate in intravenous perfusion, sedation and pain relief.Conclusions: physicians in rural or suburban areas should be aware of the possibility of receiving patients with latrodectism, due to the nonspecific clinical picture, which makes diagnosis difficult. It would be convenient to carry out toxicological studies in Cuba about Latrodectus mactans, due to the health problem that implies its toxicity and not having the specific antidote(AU)

Zvonimir Maretic (1921-1989): The History of Discovery of the First European Antilatrodectic Serum and its Preparator in the Occasion Of the 30th Anniversary of His Death

Zvonimir Maretic was the pioneer of the study of venomous animals and plants, toxicology, and tourism medicine. His achievements have been recognized, but insufficiently researched. His work covers a broad range of biomedical sciences: from public health, ecology, and environmental protection, to epidemiology and infectology. Maretic was one of the founding members of the International Society on Toxinology and the Toxicon journal's first Editorial Board. He was the first in Europe to prepare the antilatrodectic serum and to successfully apply the weever and scorpionfish antiserum on humans. This brief note tries to commemorate the achievements of Maretic, up to now poorly recognized and insufficiently researched.