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1.
Toxicon ; 188: 76-79, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33068558

RESUMO

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.


Assuntos
Antivenenos/uso terapêutico , Viúva Negra , Receptores Imunológicos , Picaduras de Aranhas/tratamento farmacológico , Animais , Humanos
2.
Toxicon ; 179: 107-110, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32179049

RESUMO

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.


Assuntos
Antídotos/uso terapêutico , Viúva Negra , Picaduras de Aranhas/tratamento farmacológico , Animais , Antivenenos , Humanos , Itália
3.
Ann Emerg Med ; 74(3): 439-449, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30926190

RESUMO

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.


Assuntos
Antivenenos/uso terapêutico , Viúva Negra , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Fatores Imunológicos/uso terapêutico , Picaduras de Aranhas/tratamento farmacológico , Adolescente , Adulto , Idoso , Animais , Criança , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/tratamento farmacológico , Medição da Dor , Venenos de Aranha/envenenamento , Adulto Jovem
4.
J Enzyme Inhib Med Chem ; 34(1): 310-321, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30734604

RESUMO

Loxosceles spiders' venoms consist of a mixture of proteins, including the sphingomyelinases D (SMases D), which are the main toxic components responsible for local and systemic effects in human envenomation. Herein, based on the structural information of SMase D from Loxosceles laeta spider venom and virtual docking-based screening approach, three benzene sulphonate compounds (named 1, 5 and 6) were identified as potential Loxosceles SMase D inhibitors. All compounds inhibited the hydrolysis of the sphingomyelin substrate by both recombinant and native SMases D. Compounds 5 and 6 acted as SMases D uncompetitive inhibitors with Ki values of 0.49 µM and 0.59 µM, respectively. Compound 1 is a mixed type inhibitor, and presented a Ki value of 0.54 µM. In addition, the three compounds inhibited the binding of SMases D to human erythrocytes and the removal of glycophorin C from the cell surface, which are important events in the complement-dependent haemolysis induced by Loxosceles venom. Moreover, compounds 5 and 6 reduced the binding of SMases to human keratinocytes membrane and the venom induced cell death. Importantly, compounds 5 and 6 also controlled the development of the necrotic lesion in an in vivo model of loxoscelism. Together, our findings indicate that the novel SMase D inhibitors presented here are able to suppress both local and systemic reactions induced by Loxosceles venoms. Since the number of Loxosceles envenomation accidents is currently growing worldwide, our results indicate that both inhibitors are promising scaffolds for the rational design of new drugs targeting SMases D from these spiders.


Assuntos
Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases/metabolismo , Dermatopatias/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/farmacologia , Picaduras de Aranhas/tratamento farmacológico , Animais , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Humanos , Estrutura Molecular , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/química , Coelhos , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Aranhas
6.
J Pediatr Hematol Oncol ; 41(1): 28-33, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30028826

RESUMO

Brown recluse spider bites can cause local and systemic signs, including rash, dermonecrosis, edema, hemolysis, and acute kidney failure. These are mostly attributed to sphingomyelinase D, the main toxin. To evaluate the severity of the disease in pediatric patients with and without neutropenia, we retrospectively reviewed records of patients treated at St. Jude Children's Research Hospital between 1970 and 2015 and identified 19 patients who met the inclusion criteria. Variables of interest included the type of underlying illness, presence of neutropenia, number of days of hospitalization, disease signs and outcome of the bite, and treatments administered. We used descriptive statistics to summarize the manifestations and severity of spider bites in patients with and without neutropenia. Six patients experienced pain from the bite, 11 had erythema, 7 developed edema, and 5 had fever. The response to spider bites in neutropenic patients was no milder than that in non-neutropenic individuals. Six patients developed systemic complications. Compared with non-neutropenic patients, neutropenic patients had antibiotics prescribed more often and experienced longer hospital stays. Spider bites do not seem to have a different clinical course in neutropenic patients. Therefore, a conservative approach may be best for these patients, with close monitoring and local wound care.


Assuntos
Antibacterianos/administração & dosagem , Neutropenia/tratamento farmacológico , Índice de Gravidade de Doença , Picaduras de Aranhas/tratamento farmacológico , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Neoplasias/patologia , Neoplasias/terapia , Neutropenia/etiologia , Neutropenia/patologia , Estudos Retrospectivos , Picaduras de Aranhas/diagnóstico , Picaduras de Aranhas/patologia
7.
Rev Chilena Infectol ; 35(3): 266-275, 2018.
Artigo em Espanhol | MEDLINE | ID: mdl-30534906

RESUMO

BACKGROUND: Loxoscelism is a common pathology in our environment with a broad spectrum of differential diagnoses and presentations, with potentially serious complications, even to the point of death. To date, there is no standard treatment for these patients. AIM: To describe the clinical manifestations, main complications, therapeutic management, and evolution of loxoscelism in an inpatient setting from a tertiary hospital in Chile. METHODS: All patients consulting and hospitalized in the hospital of the Pontificia Universidad Católica de Chile with diagnosis of loxoscelism between 2014 to 2017 and evaluated by dermatologist were included. Review of clinical files, including symptoms, images, laboratory parameters and treatment. RESULTS: We evaluated seventeen inpatient with loxoscelism, whose presentation responds to the national epidemiological pattern. Most cases were managed with antibiotics, systemic corticosteroids, antihistamines, and dapsone. From these, 11.8% corresponded to viscerocutaneous loxoscelism, successfully managed with supportive measures, systemic corticosteroids and antihistamines. Fifty-nine percent healed their cutaneous lesions after one month of treatment, with slight residual scarring or post inflammatory hyperpigmentation, without associated mortality in our series. DISCUSSION: Most cases of cutaneous loxoscelism presented excellent response and rapid resolution of the disease after combined therapy with systemic corticosteroids, antibiotics and dapsone, suggesting that the use of these therapies could stop the progression of cutaneous necrosis and prevent complications associated with loxoscelism.


Assuntos
Dermatopatias/etiologia , Picaduras de Aranhas/complicações , Venenos de Aranha/efeitos adversos , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estações do Ano , Dermatopatias/diagnóstico , Dermatopatias/tratamento farmacológico , Picaduras de Aranhas/diagnóstico , Picaduras de Aranhas/tratamento farmacológico , Vísceras/patologia , Adulto Jovem
8.
Toxins (Basel) ; 10(11)2018 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-30400220

RESUMO

Snakes, scorpions, and spiders are venomous animals that pose a threat to human health, and severe envenomings from the bites or stings of these animals must be treated with antivenom. Current antivenoms are based on plasma-derived immunoglobulins or immunoglobulin fragments from hyper-immunized animals. Although these medicines have been life-saving for more than 120 years, opportunities to improve envenoming therapy exist. In the later decades, new biotechnological tools have been applied with the aim of improving the efficacy, safety, and affordability of antivenoms. Within the avenues explored, novel immunization strategies using synthetic peptide epitopes, recombinant toxins (or toxoids), or DNA strings as immunogens have demonstrated potential for generating antivenoms with high therapeutic antibody titers and broad neutralizing capacity. Furthermore, these approaches circumvent the need for venom in the production process of antivenoms, thereby limiting some of the complications associated with animal captivity and venom collection. Finally, an important benefit of innovative immunization approaches is that they are often compatible with existing antivenom manufacturing setups. In this review, we compile all reported studies examining venom-independent innovative immunization strategies for antivenom development. In addition, a brief description of toxin families of medical relevance found in snake, scorpion, and spider venoms is presented, as well as how biochemical, bioinformatic, and omics tools could aid the development of next-generation antivenoms.


Assuntos
Antivenenos/administração & dosagem , Antivenenos/biossíntese , Mordeduras de Serpentes/tratamento farmacológico , Picaduras de Aranhas/tratamento farmacológico , Animais , Antivenenos/imunologia , Humanos , Venenos de Serpentes/imunologia , Venenos de Aranha/imunologia
9.
Toxins (Basel) ; 10(9)2018 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-30201918

RESUMO

Diagnostic tests for arachnid accidents remain unavailable for patients and clinicians. Together with snakes, these accidents are still a global medical concern, and are recognized as neglected tropical issues. Due to arachnid toxins' fast mechanism of action, quick detection and quantification of venom is required to accelerate treatment decisions, rationalize therapy, and reduce costs and patient risks. This review aims to understand the current limitations for arachnid venom identification and quantification in biological samples. We benchmarked the already existing initiatives regarding test requirements (sample or biomarkers of choice), performances (time, detection limit, sensitivity and specificity) and their validation (on animal models or on samples from envenomed humans). Our analysis outlines unmet needs for improving diagnosis and consequently treatment of arachnid accidents. Hence, based on lessons from past attempts, we propose a road map for raising best practice guidelines, leading to recommendations for future progress in the development of arachnid diagnostic assays.


Assuntos
Picaduras de Aranhas/diagnóstico , Venenos de Aranha/análise , Animais , Antivenenos/uso terapêutico , Bioensaio , Testes Diagnósticos de Rotina , Humanos , Picaduras de Aranhas/tratamento farmacológico
10.
Pediatr Dermatol ; 35(6): e422-e424, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30230593

RESUMO

A 27-month-old girl with a history of congenital myopathy presented with two indurated, pink plaques involving the right arm and left thigh. Closer examination identified central puncta within these plaques, which reportedly occurred at sites of witnessed arachnid bites. After confirmation of the spider species as Trachelas tranquillus, she was treated to address cutaneous inflammation and suspected superinfection using oral and topical antibiotics as well as topical corticosteroid resulting in prompt resolution of her lesions. Trachelas tranquillus should be considered as a possible source of inflammatory spider bites that can become superinfected.


Assuntos
Antibacterianos/uso terapêutico , Glucocorticoides/uso terapêutico , Picaduras de Aranhas/diagnóstico , Animais , Criança , Pré-Escolar , Feminino , Humanos , Picaduras de Aranhas/complicações , Picaduras de Aranhas/tratamento farmacológico , Aranhas , Superinfecção/tratamento farmacológico
11.
Toxicon ; 138: 59-67, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28811247

RESUMO

Bites of tiger spiders belonging to Poecilotheria genus cause moderate to severe pain and long-lasting local or generalized muscle cramps in humans. Bites occur in regions of the spiders' natural habitat, India and Sri Lanka, but the popularity of these colorful tarantulas as pets leads to reports of envenomation cases worldwide. Treatment is predominantly symptomatic and often inadequate since there is almost no clinical or toxicology research data available, and physicians outside India or Sri Lanka typically have no experience in treating such cases. We report toxicity studies of venom from nine Poecilotheria species in laboratory mice (Mus musculus Balb/C males). LD50 values are 5-14 mg of lyophilized crude venom per 1 kg (i.v.). The major symptoms of envenomation include tonic-clonic seizures, jerks, characteristic motor stereotypy, and hyperalgesia and point to voltage-gated sodium channels as a potential target of the venom components. Poecilotheria fasciata venom effects were studied in detail at a sub-lethal dose of 5 mg/kg (LD50 = 12 mg/kg). 13 widely used pharmacological agents (atropine, chloropyramine, chlorpromazine, diazepam, ethanol, flupirtine, haloperidol, ketotifen, lamotrigine, oxcarbazepine, tolperisone, xylazine, and CaCl2) were checked for ability to suppress the envenomation symptoms. Chlorpromazine (10 mg/kg, i.p.), oxcarbazepine (60 mg/kg, p.o.), tolperisone (50 mg/kg, s.c.) and xylazine (2.5 mg/kg, i.p.) were found effective as a pretreatment to mitigate muscle cramps and motor stereotypy. When administered after envenomation chlorpromazine (5 mg/kg, i.v.) effectively reduced the cramps, while oxcarbazepine (30 mg/kg, i.v.) and xylazine (1 mg/kg, i.v.) suppressed the stereotypy.


Assuntos
Cãibra Muscular/tratamento farmacológico , Picaduras de Aranhas/tratamento farmacológico , Venenos de Aranha/toxicidade , Transtorno de Movimento Estereotipado/tratamento farmacológico , Animais , Clorpromazina/farmacologia , Hiperalgesia , Masculino , Camundongos Endogâmicos BALB C , Oxcarbazepina/farmacologia , Convulsões , Canais de Sódio Disparados por Voltagem , Xilazina/farmacologia
12.
Rev. Col. Méd. Cir. Guatem ; 156(1): 47-50, 2017 jul. ilus
Artigo em Espanhol | LILACS | ID: biblio-982135

RESUMO

La mordedura por araña del género Loxosceles produce dermonecrosis en el sitio de la lesión y complicaciones sistémicas secundarias a reacciones enzimáticas de su veneno, lo que aumenta la tasa de mortalidad. El objetivo es reportar cuatro casos de loxoscelismo atendidos en el hospital General San Juan de Dios, donde los pacientes tuvieron una evolución satisfactoria a pesar de la inexistencia del antiveneno como manejo ideal de la toxicidad (AU)


Assuntos
Humanos , Feminino , Picaduras de Aranhas/tratamento farmacológico , Venenos de Aranha/efeitos adversos , Aranha Marrom Reclusa/patogenicidade , Hemólise , Guatemala
14.
Toxins (Basel) ; 9(4)2017 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-28430165

RESUMO

Latrodectism or envenomation by widow-spiders is common and clinically significant worldwide. Alpha-latrotoxin is the mammalian-specific toxin in the venom that results in toxic effects observed in humans. Symptoms may be incapacitating and include severe pain that can persist for days. The management of mild to moderate latrodectism is primarily supportive while severe cases have variously been treated with intravenous calcium, muscle relaxants, widow-spider antivenom and analgesic opioids. The object of this systematic review is to examine the literature on the clinical effectiveness of past and current treatments for latrodectism. MEDLINE, EMBASE and Google Scholar were searched from 1946 to December 2016 to identify clinical studies on the treatment of latrodectism. Studies older than 40 years and not in English were not reviewed. There were only two full-publications and one abstract of placebo-controlled randomised trials on antivenom use for latrodectism. Another two randomised comparative trials compared the route of administration of antivenom for latrodectism. There were fourteen case series (including two abstracts), fourteen case reports and one letter investigating drug treatments for latrodectism with the majority of these also including antivenom for severe latrodectism. Antivenom with opioid analgesia is often the major treatment reported for latrodectism however; recent high quality evidence has cast doubt on the clinical effectiveness of this combination and suggests that other treatments need to be investigated.


Assuntos
Antivenenos/uso terapêutico , Picaduras de Aranhas/tratamento farmacológico , Animais , Humanos , Resultado do Tratamento
15.
J Cell Biochem ; 118(4): 726-738, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27563734

RESUMO

Loxoscelism refers to the clinical symptoms that develop after brown spider bites. Brown spider venoms contain several phospholipase-D isoforms, which are the main toxins responsible for both the cutaneous and systemic effects of loxoscelism. Understanding of the phospholipase-D catalytic mechanism is crucial for the development of specific treatment that could reverse the toxic effects caused by the spider bite. Based on enzymatic, biological, structural, and thermodynamic tests, we show some features suitable for designing drugs against loxoscelism. Firstly, through molecular docking and molecular dynamics predictions, we found three different molecules (Suramin, Vu0155056, and Vu0359595) that were able to bind the enzyme's catalytic site and interact with catalytically important residues (His12 or His47) and with the Mg2+ co-factor. The binding promoted a decrease in the recombinant brown spider venom phospholipase-D (LiRecDT1) enzymatic activity. Furthermore, the presence of the inhibitors reduced the hemolytic, dermonecrotic, and inflammatory activities of the venom toxin in biological assays. Altogether, these results indicate the mode of action of three different LiRecDT1 inhibitors, which were able to prevent the venom toxic effects. This strengthen the idea of the importance of designing a specific drug to treat the serious clinical symptoms caused by the brown spider bite, a public health problem in several parts of the world, and until now without specific treatment. J. Cell. Biochem. 118: 726-738, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Proteínas de Artrópodes/antagonistas & inibidores , Aranha Marrom Reclusa/enzimologia , Desenho de Fármacos , Fosfolipase D/antagonistas & inibidores , Venenos de Aranha/antagonistas & inibidores , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Benzimidazóis/farmacologia , Aranha Marrom Reclusa/genética , Aranha Marrom Reclusa/patogenicidade , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Hemólise/efeitos dos fármacos , Humanos , Cinética , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Necrose , Fosfolipase D/química , Fosfolipase D/genética , Diester Fosfórico Hidrolases/química , Diester Fosfórico Hidrolases/genética , Piperidinas/farmacologia , Coelhos , Proteínas Recombinantes/genética , Pele/efeitos dos fármacos , Pele/patologia , Picaduras de Aranhas/tratamento farmacológico , Picaduras de Aranhas/enzimologia , Venenos de Aranha/química , Venenos de Aranha/genética , Suramina/farmacologia
17.
Toxins (Basel) ; 8(8)2016 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-27455327

RESUMO

Spiders and scorpions are notorious for their fearful dispositions and their ability to inject venom into prey and predators, causing symptoms such as necrosis, paralysis, and excruciating pain. Information on venom composition and the toxins present in these species is growing due to an interest in using bioactive toxins from spiders and scorpions for drug discovery purposes and for solving crystal structures of membrane-embedded receptors. Additionally, the identification and isolation of a myriad of spider and scorpion toxins has allowed research within next generation antivenoms to progress at an increasingly faster pace. In this review, the current knowledge of spider and scorpion venoms is presented, followed by a discussion of all published biotechnological efforts within development of spider and scorpion antitoxins based on small molecules, antibodies and fragments thereof, and next generation immunization strategies. The increasing number of discovery and development efforts within this field may point towards an upcoming transition from serum-based antivenoms towards therapeutic solutions based on modern biotechnology.


Assuntos
Antivenenos/uso terapêutico , Biotecnologia/tendências , Descoberta de Drogas/tendências , Picadas de Escorpião/tratamento farmacológico , Venenos de Escorpião/antagonistas & inibidores , Picaduras de Aranhas/tratamento farmacológico , Venenos de Aranha/antagonistas & inibidores , Animais , Antivenenos/química , Biologia Computacional/tendências , Bases de Dados de Proteínas/tendências , Humanos , Picadas de Escorpião/imunologia , Picadas de Escorpião/metabolismo , Venenos de Escorpião/imunologia , Venenos de Escorpião/metabolismo , Picaduras de Aranhas/imunologia , Picaduras de Aranhas/metabolismo , Venenos de Aranha/imunologia , Venenos de Aranha/metabolismo
18.
PLoS One ; 11(5): e0156386, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27227455

RESUMO

BACKGROUND: A better knowledge of the burden and risk factors associated with severity due to spider bites would lead to improved management with a reduction of sequelae usually seen for this neglected health problem, and would ensure proper use of antivenoms in remote localities in the Brazilian Amazon. The aim of this study was to analyze the profile of spider bites reported in the state of Amazonas in the Western Brazilian Amazon, and to investigate potential risk factors associated with severity of envenomation. METHODOLOGY/PRINCIPAL FINDINGS: We used a case-control study in order to identify factors associated with spider bite severity in the Western Brazilian Amazon from 2007 to 2014. Patients evolving to any severity criteria were considered cases and those with non-severe bites were included in the control group. All variables were retrieved from the official Brazilian reporting systems. Socioeconomical and environmental components were also included in a multivariable analysis in order to identify ecological determinants of incidence and severity. A total of 1,181 spider bites were recorded, resulting in an incidence of 4 cases per 100,000 person/year. Most of the spider bites occurred in males (65.8%). Bites mostly occurred in rural areas (59.5%). The most affected age group was between 16 and 45 years old (50.9%). A proportion of 39.7% of the bites were related to work activities. Antivenom was prescribed to 39% of the patients. Envenomings recorded from urban areas [Odds ratio (OR) = 0.40 (95%CI = 0.30-0.71; p<0.001)] and living in a municipality with a mean health system performance index (MHSPI >median [OR = 0.64 (95%CI = 0.39-0.75; p<0.001)] were independently associated with decreased risk of severity. Work related accidents [OR = 2.09 (95%CI = 1.49-2.94; p<0.001)], Indigenous status [OR = 2.15 (95%CI = 1.19-3.86; p = 0.011)] and living in a municipality located >300 km away from the state capital Manaus [OR = 1.90 (95%CI = 1.28-2.40; p<0.001)] were independently associated with a risk of severity. Living in a municipality located >300 km away from the state capital Manaus [OR = 1.53 (95%CI = 1.15-2.02; p = 0.003)] and living in a municipality with a MHSPI 300 km away from the state capital Manaus could be contributing factors to higher severity of spider envenomings in this area, as well as to antivenom underdosage.


Assuntos
Antivenenos/administração & dosagem , Assistência à Saúde , Gestão de Riscos , Picaduras de Aranhas/tratamento farmacológico , Picaduras de Aranhas/epidemiologia , Adolescente , Adulto , Brasil/epidemiologia , Estudos de Casos e Controles , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fatores de Risco
20.
Clin Toxicol (Phila) ; 54(3): 245-51, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26678882

RESUMO

CONTEXT: Funnel-web spider (Atrax and Hadronyche spp.) envenoming is rare but causes severe neuromuscular, autonomic, and cardiac effects. A rabbit-derived IgG antivenom is available, but venom detection in patients has not been reported. OBJECTIVE: To use serial venom and antivenom concentrations to better define envenoming and antivenom effectiveness. MATERIALS AND METHODS: Serum was collected from nine patients with suspected funnel-web spider bites and clinical effects were recorded. Venom-specific enzyme immunoassays were developed to measure funnel-web spider venom and antivenom concentrations. Goat anti-rabbit whole serum was coupled to UltraLink resin and added to samples to remove bound venom and measure free venom. Antivenom efficacy was defined as antivenom binding all free venom and antivenom effectiveness as resolution of clinical features. RESULTS: Venom was detectable in samples from six of nine patients. In three patients without venom detected, there were only moderate effects, which did not completely respond to antivenom in all cases and no spider was identified. In five of six cases, a male Atrax spp. (Sydney funnel-web) spider was identified. Three patients had moderate envenoming which responded to antivenom. Three patients had severe envenoming and developed catecholamine-induced myocarditis and acute pulmonary oedema. Although cholinergic and non-specific clinical features appeared to respond to antivenom, myocarditis and pulmonary oedema lasted 2-4 days. Median venom concentration pre-antivenom in five patients with samples was 5.6 ng/ml (3-35 ng/ml), and immediately post-antivenom decreased to a median of 0 ng/ml (0-1.8 ng/ml). Post-antivenom venom concentrations decreased when bound venom was removed; median, 0 ng/ml (0-0.9 ng/ml), indicating that most venom detected post-antivenom was bound. There was recurrence of venom and clinical features in one patient when a pressure bandage was removed. CONCLUSIONS: Detection of venom in suspected funnel-web spider bites identified definite cases with characteristic envenoming and a spider was identified. Measurement of venom concentrations pre- and post-antivenom demonstrated that venom was bound by antivenom, but in severe cases cardiac toxicity was not reversed.


Assuntos
Antivenenos/análise , Picaduras de Aranhas/tratamento farmacológico , Venenos de Aranha/antagonistas & inibidores , Venenos de Aranha/análise , Adolescente , Adulto , Idoso , Animais , Doenças do Sistema Nervoso Autônomo/induzido quimicamente , Doenças do Sistema Nervoso Autônomo/tratamento farmacológico , Pré-Escolar , Feminino , Cabras/imunologia , Humanos , Técnicas Imunoenzimáticas , Imunoglobulina G/análise , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Miocardite/induzido quimicamente , Miocardite/tratamento farmacológico , Edema Pulmonar/induzido quimicamente , Edema Pulmonar/tratamento farmacológico , Coelhos , Recidiva , Adulto Jovem
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