ABSTRACT
Snakebites affect millions of people worldwide. The majority of research and management about snakebites focus on venom and antivenom, with less attention given to snake ecology. The fundamental factor in snakebites is the snakes' defensive biting behavior. Herein we examine the effects of environmental variables (temperature, time of day, and human stimulus) and biological variables (sex and body size) on the biting behavior of a medically significant pit viper species in Brazil, Bothrops jararaca (Viperidae), and associate it with the epidemiology of snakebites. Through experimental simulations of encounters between humans and snakes, we obtained behavioral models applicable to epidemiological situations in the State of São Paulo, Brazil. We found a significant overlap between behavioral, morphological, environmental, and epidemiological data. Variables that increase snakebites in epidemiological data also enhance the tendency of snakes to bite defensively, resulting in snakebites. We propose that snakebite incidents are influenced by environmental and morphological factors, affecting the behavior of snakes and the proportion of incidents. Thus, investigating behavior of snakes related to snakebite incidents is a valuable tool for a better understanding of the epidemiology of these events, helping the prediction and, thus, prevention of snakebites.
Subject(s)
Behavior, Animal , Bothrops , Snake Bites , Snake Bites/epidemiology , Snake Bites/psychology , Animals , Humans , Male , Female , Brazil/epidemiology , Venomous SnakesABSTRACT
Snakebites affect millions of people worldwide. The majority of research and management about snakebites focus on venom and antivenom, with less attention given to snake ecology. The fundamental factor in snakebites is the snakes’ defensive biting behavior. Herein we examine the effects of environmental variables (temperature, time of day, and human stimulus) and biological variables (sex and body size) on the biting behavior of a medically significant pit viper species in Brazil, Bothrops jararaca (Viperidae), and associate it with the epidemiology of snakebites. Through experimental simulations of encounters between humans and snakes, we obtained behavioral models applicable to epidemiological situations in the State of São Paulo, Brazil. We found a significant overlap between behavioral, morphological, environmental, and epidemiological data. Variables that increase snakebites in epidemiological data also enhance the tendency of snakes to bite defensively, resulting in snakebites. We propose that snakebite incidents are influenced by environmental and morphological factors, affecting the behavior of snakes and the proportion of incidents. Thus, investigating behavior of snakes related to snakebite incidents is a valuable tool for a better understanding of the epidemiology of these events, helping the prediction and, thus, prevention of snakebites.
ABSTRACT
Bites of “nonvenomous” snakes can sometimes be mistaken for the bites of venomous snakes. As an example of this confusion, this report describes confirmed bites by Philodryas olfersii and Bothrops jararaca. In the first case, a 55-y-old man with a history of controlled hypertension was bitten on his right forearm by P olfersii. Physical examination revealed extensive edema, erythema, and widespread ecchymoses throughout his right upper limb. Laboratory tests indicated leukocytosis and high D-dimer levels, but normal coagulation, suggestive of a resolved recent coagulopathy. He received only supportive treatment. In the second case, a healthy 35-y-old man was bitten by B jararaca. Although the anatomic region of the bite and the results of physical examination were similar to those in the first case, laboratory tests showed mild coagulopathy, leukocytosis, and high D-dimer levels. The patient was treated with antivenom. In both cases, the 20-min whole blood clotting test results were normal. Patients bitten by P olfersii may present with local symptoms resembling B jararaca envenomation. Without snake identification and the detection of venom-induced consumption coagulopathy, especially in places where the 20-min whole blood clotting test is the only clotting test available, it is almost impossible to establish an accurate and safe differential diagnosis. In this context, the best alternative is to take the risk of prescribing antivenom for a possible P olfersii bite rather than failing to do so for a real Bothrops bite. Late treatment for Bothrops bite can result in severe complications and sequelae.
ABSTRACT
Despite the biological relevance and abundance of non-front-fanged colubroid snakes, little is known about their medical significance. Here, we describe the clinical, epidemiological, and biological aspects of bites by two colubroid species. We retrospectively analyzed cases of Xenodon merremii and Xenodon neuwiedii bites in which the offending snake was clearly identified. Analyses included variables related to the snake and the patient, including demographic data, clinical findings, and treatments. Of the 163 cases, 123 were bites by X. merremii and 40 by X. neuwiedii. Most bites occurred in spring and summer, predominantly during the daytime. Most offending snakes were female. Bites by X. merremii juveniles were more frequent in autumn than in other seasons, whereas those by X. neuwiedii adults were in the summer. Hands and feet were the most frequently affected regions, with no significant difference between upper and lower limbs bitten by either X. merremii or X. neuwiedii. The main clinical findings were pain, transitory bleeding, erythema, and local edema. Local edema was proportionally more frequent with X. neuwiedii bites than with X. merremii bites. No patient had extensive edema or systemic envenomation. A significant association between the snout-vent-length and transitory bleeding in bites by X. merremii, but not in those by X. neuwiedii, was identified. Whole blood clotting tests were normal in all tested patients (62 cases). Sixteen patients were incorrectly treated with anti-Bothrops antivenom. In conclusion, most accidents caused by X. merremii and X. neuwiedii present mild local symptomatology. These snakes can be mistaken for lance-headed vipers, and some bites present symptoms that resemble mild bites by Bothrops sp. Physicians should be aware of X. merremii and X. neuwiedii bites to avoid unnecessary patient distress and overprescription of antivenom.
ABSTRACT
Despite the biological relevance and abundance of non-front-fanged colubroid snakes, little is known about the medical significance of the majority these species. Herein, we described bites by two green racer species of colubroid snakes, with respect to clinical, epidemiological, and biological features. We retrospectively analyzed proven cases of Philodryas olfersii and Philodryas aestiva bites. Only cases in which the causative animal was brought and identified by an expert were included. Analysis included variables related to the snake, patient demographics, clinical findings, whole blood clotting time (WBCT20), and treatments. Total 155 medical records were analyzed, of which 141 and 14 patients each were bitten by P. olfersii and P. aestiva, respectively. Most bites occurred in spring and summer seasons, predominantly during daytime. Most snakes were female and adult. Bites by P. olfersii adults were more frequent in summer (p < 0.001) and spring (p < 0.001). The hands were most frequently bitten by P. olfersii (59.6%), while the feet and legs (71.4%) were most bitten by P. aestiva. The most common local signs or symptoms observed were pain, edema, erythema, and transitory local bleeding. Severe pain, extensive edema, ecchymosis, and paresthesia were present only in patients bitten by P. olfersii. Significant association was observed between local bleeding and adult snakes (p = 0.019), as well as between the snout-vent-length and pain (p = 0.018), extensive edema (p = 0.024), and erythema (p = 0.047). WBCT20 was normal in the 35 cases in which it was available. Two patients were wrongly treated with anti-Bothrops antivenom. These results indicated that most accidents caused by P. olfersii and P. aestiva present mild local symptomatology. Some bites of P. olfersii bites may present local symptoms, resembling bites by Bothrops-like snakes. Physicians should be informed about these kinds of accidents, to avoid unnecessary distress to the patient and over prescription of antivenom.
ABSTRACT
A survey in São Paulo, Brazil, assessed travel agents’ knowledge on travellers’ health. Data were collected using an online questionnaire. Of 200 agencies contacted, 32 answered (34 agents). Most consultants reported discussing personal safety, healt insurance and vaccination. Few provided information on water and food diseases or sexually transmitted infections.
ABSTRACT
A 44-year-old healthy farmer, was stung by a scorpion on his right hand while preparing soil for planting in the Caatinga area (a large area in the north-east of Brazil characterized by semiarid scrub forest), in the Catarina Municipality countryside, Ceará State, Brazil. According to the reports of carers and family members, the patient initially reported mild pain at the site of the sting, but within a few minutes he developed malaise, pruritus in the body and throat, edema in the nostrils, and a dry mouth which led to looking for water to drink. It rapidly evolved into sphincter, urinary and fecal release, salivation and a convulsive episode with loss of the senses. He was dead on arrival at Catarina Municipality Hospital emergency department. The necroscopic report indicated suffocation due to glottal edema and acute lung edema as the "cause of death". The animal which caused the accident was under a rock that the patient was manipulating at the time of the incident, and has been identified by experts as Jaguajir rochae (Borelli, 1910) scorpion species, formerly synonymized Rhopalurus rochae. This is the first report of a fatality due to an allergic reaction to the venom of this species. This leads to the possibility that deaths caused by stings from other scorpion species may be due to anaphylaxis, whose symptoms in some situations may be confused with severe envenomation.
Subject(s)
Poisoning , Scorpions , Bites and Stings , Hypersensitivity , AnaphylaxisABSTRACT
Infrared thermography is a technique that quantifies the thermal (infrared) radiation emitted by an object and produces a high-resolution, digital thermal image of it. Medically, this technique is used to visualize the body's surface temperature distribution in a non-invasive, safe, and convenient fashion. However, to the best of our knowledge, the use of infrared thermography for assessing the systemic effects of envenomation by coral snakes has not been reported. In this case report, we describe the use of this technique in the management of a case of snakebite in Sao Paulo, Brazil. A 51-year-old woman was bitten on the back of the right hand by Micrurus frontalis, a species of coral snake, 10 min prior to her arrival at the hospital. Infrared imaging performed at admission revealed elevated temperatures at the bite site and in the elbow, as well as the preservation of a normal distal thermal gradient in both hands. A few minutes later, the patient developed muscle weakness in the upper limbs and in the eyelids, and infrared imaging showed an alteration of the thermal gradient in both hands, reflecting the systemic action of the venom. Following these observations, the patient was treated with the specific antivenom and was discharged 48 h post admission. At the two-week follow-up, the thermal image obtained showed no anomalies, indicating the recovery of the patient. Hence, infrared thermography can be very useful in the early identification of systemic neurotoxicity in cases of Micrurus snake bites, facilitating the decision to prescribe the antivenom.
ABSTRACT
Infrared thermography is a technique that quantifies the thermal (infrared) radiation emitted by an object and produces a high-resolution, digital thermal image of it. Medically, this technique is used to visualize the body's surface temperature distribution in a non-invasive, safe, and convenient fashion. However, to the best of our knowledge, the use of infrared thermography for assessing the systemic effects of envenomation by coral snakes has not been reported. In this case report, we describe the use of this technique in the management of a case of snakebite in Sao Paulo, Brazil. A 51-year-old woman was bitten on the back of the right hand by Micrurus frontalis, a species of coral snake, 10 min prior to her arrival at the hospital. Infrared imaging performed at admission revealed elevated temperatures at the bite site and in the elbow, as well as the preservation of a normal distal thermal gradient in both hands. A few minutes later, the patient developed muscle weakness in the upper limbs and in the eyelids, and infrared imaging showed an alteration of the thermal gradient in both hands, reflecting the systemic action of the venom. Following these observations, the patient was treated with the specific antivenom and was discharged 48 h post admission. At the two-week follow-up, the thermal image obtained showed no anomalies, indicating the recovery of the patient. Hence, infrared thermography can be very useful in the early identification of systemic neurotoxicity in cases of Micrurus snake bites, facilitating the decision to prescribe the antivenom.
ABSTRACT
A total of 86 proven cases ofTomodon dorsatusbites admitted to Hospital Vital Brazil (HVB) of ButantanInstitute, in São Paulo, Brazil, between 1945 and 2018, were retrospectively analyzed. The cases included werethose in which the snake was brought to HVB and was correctly identified. Of the 86 cases of snake bites, it waspossible to describe the sex of the snake in 52 cases; 31 (59.6%) snakes were male. Only 52 snakes out of 86could be studied because of their preservation status. The length of snakes (snout–vent length) ranged from 180to 770 mm. Of the 86 snakes, 72 could be distinguished as adults (n = 63, 87.5%) or juveniles (n = 9, 12.5%).Most bites occurred in the spring and summer seasons (n = 57, 66.3%) and during warmer periods of the day(n = 61, 72.6%), between 9A.M. and 3P.M. The mean ( ± standard deviation) age of the victims was 26.9 ± 17.2 years, and 60 (69.8%) were men.Approximately 90% of the patients sought medical care within 6 h after the bite. Both upper (n = 45, 52.3%)and lower (n = 37, 43.0%) limbs were the most frequently bitten, particularly the feet and hands (n = 54,62.8%). The local clinical manifestations were pain (n = 55, 64.0%), transitory bleeding (n = 23, 26.7%), er-ythema (n = 22, 25.6%), edema (n = 14, 16.3%), paresthesia (n = 9, 10.5%), and ecchymosis (n = 3, 3.5%).Only 10 (11.6%) patients reported non-specific systemic symptoms characterized by transient dizziness or mildheadache, and 21 (24.4%) patients showed no evidence of envenomation. A 20 min whole blood clotting test wasperformed in 31 (36.0%) patients on admission and all of them had coagulable blood. Supportive treatment wasoffered to 38 (44.2%) patients, namely, antiseptic (n = 20, 23.3%), antihistamines (n = 12, 14.0%), and an-algesics (n = 9, 10.5%). Four (4.7%) patients were inappropriately treated withBothropsantivenom before theiradmission to HVB. No sequelae or relevant complications were observed in patients, and the prognosis wasbenign. Therefore, althoughT. dorsatusbites can cause mild local symptomatology, it is important that healthprofessionals know how to make the correct diagnosis to avoid unnecessary use of antivenom.
ABSTRACT
Infrared thermography is a technique that quantifies the thermal (infrared) radiation emitted by an object and produces a high-resolution, digital thermal image of it. Medically, this technique is used to visualize the body's surface temperature distribution in a non-invasive, safe, and convenient fashion. However, to the best of our knowledge, the use of infrared thermography for assessing the systemic effects of envenomation by coral snakes has not been reported. In this case report, we describe the use of this technique in the management of a case of snakebite in Sao Paulo, Brazil. A 51-year-old woman was bitten on the back of the right hand by Micrurus frontalis, a species of coral snake, 10 min prior to her arrival at the hospital. Infrared imaging performed at admission revealed elevated temperatures at the bite site and in the elbow, as well as the preservation of a normal distal thermal gradient in both hands. A few minutes later, the patient developed muscle weakness in the upper limbs and in the eyelids, and infrared imaging showed an alteration of the thermal gradient in both hands, reflecting the systemic action of the venom. Following these observations, the patient was treated with the specific antivenom and was discharged 48 h post admission. At the two-week follow-up, the thermal image obtained showed no anomalies, indicating the recovery of the patient. Hence, infrared thermography can be very useful in the early identification of systemic neurotoxicity in cases of Micrurus snake bites, facilitating the decision to prescribe the antivenom.
ABSTRACT
A total of 86 proven cases ofTomodon dorsatusbites admitted to Hospital Vital Brazil (HVB) of ButantanInstitute, in São Paulo, Brazil, between 1945 and 2018, were retrospectively analyzed. The cases included werethose in which the snake was brought to HVB and was correctly identified. Of the 86 cases of snake bites, it waspossible to describe the sex of the snake in 52 cases; 31 (59.6%) snakes were male. Only 52 snakes out of 86could be studied because of their preservation status. The length of snakes (snout–vent length) ranged from 180to 770 mm. Of the 86 snakes, 72 could be distinguished as adults (n = 63, 87.5%) or juveniles (n = 9, 12.5%).Most bites occurred in the spring and summer seasons (n = 57, 66.3%) and during warmer periods of the day(n = 61, 72.6%), between 9A.M. and 3P.M. The mean ( ± standard deviation) age of the victims was 26.9 ± 17.2 years, and 60 (69.8%) were men.Approximately 90% of the patients sought medical care within 6 h after the bite. Both upper (n = 45, 52.3%)and lower (n = 37, 43.0%) limbs were the most frequently bitten, particularly the feet and hands (n = 54,62.8%). The local clinical manifestations were pain (n = 55, 64.0%), transitory bleeding (n = 23, 26.7%), er-ythema (n = 22, 25.6%), edema (n = 14, 16.3%), paresthesia (n = 9, 10.5%), and ecchymosis (n = 3, 3.5%).Only 10 (11.6%) patients reported non-specific systemic symptoms characterized by transient dizziness or mildheadache, and 21 (24.4%) patients showed no evidence of envenomation. A 20 min whole blood clotting test wasperformed in 31 (36.0%) patients on admission and all of them had coagulable blood. Supportive treatment wasoffered to 38 (44.2%) patients, namely, antiseptic (n = 20, 23.3%), antihistamines (n = 12, 14.0%), and an-algesics (n = 9, 10.5%). Four (4.7%) patients were inappropriately treated withBothropsantivenom before theiradmission to HVB. No sequelae or relevant complications were observed in patients, and the prognosis wasbenign. Therefore, althoughT. dorsatusbites can cause mild local symptomatology, it is important that healthprofessionals know how to make the correct diagnosis to avoid unnecessary use of antivenom.
ABSTRACT
Abstract INTRODUCTION Infrared imaging (IR) is a noninvasive technique that quantifies body surface temperature, producing a digital color image. IR has been used to study diseases in which skin temperature can reflect the presence of inflammation. METHODS This was an observational pilot study of eight patients envenomed by snakes, spiders, and scorpions. All patients were examined using a thermal camera. RESULTS In all cases, we obtained infrared images that corroborated clinical findings indicating localized effects of venom, specifically inflammation. CONCLUSIONS IR has potential for use as a research, diagnostic, and monitoring tool for localized effects of animal venoms.
Subject(s)
Humans , Male , Female , Adult , Spider Bites/diagnosis , Snake Bites/diagnosis , Thermography/methods , Scorpion Stings/diagnosis , Spider Bites/complications , Snake Bites/complications , Pilot Projects , Scorpion Stings/complicationsABSTRACT
Introduction: The World Health Organization (WHO) recommends one single dose of the Yellow Fever (YF) vaccine based on studies of antibody persistency in healthy adults. We assessed the prevalence and titers of YF virus neutralizing antibodies in previously vaccinated persons aged = 60 years, in comparison to younger adults. We also evaluated the correlation between antibody titers and the time since vaccination among participants who received one vaccine dose, and the seropositivity among participants vaccinated prior to or within the past 10 years. Methods previously vaccinated healthy persons aged = 18 years were included. YF virus neutralizing antibody titers were determined by means of the 50% Plaque Reduction Neutralization Test. Results: 46 persons aged = 60 years and 48 persons aged 18 to 59 years were enrolled. There was no significant difference in the prevalence of YF virus neutralizing antibodies between the two groups (p = 0.263). However, titers were significantly lower in the elderly (p = 0.022). There was no correlation between YF virus neutralizing antibody titers and the time since vaccination. There was no significant difference in seropositivity among participants vaccinated prior to or within the past 10 years. Conclusions: the clinical relevance of the observed difference in YF virus neutralizing antibody titers between the two groups is not clear.
ABSTRACT
Introduction: Infrared imaging (IR) is a noninvasive technique that quantifies body surface temperature, producing a digital color image. IR has been used to study diseases in which skin temperature can reflect the presence of inflammation. Methods: This was an observational pilot study of eight patients envenomed by snakes, spiders, and scorpions. All patients were examined using a thermal camera. Results: In all cases, we obtained infrared images that corroborated clinical findings indicating localized effects of venom, specifically inflammation. Conclusions: IR has potential for use as a research, diagnostic, and monitoring tool for localized effects of animal venoms.
ABSTRACT
ABSTRACT Introduction: The World Health Organization (WHO) recommends one single dose of the Yellow Fever (YF) vaccine based on studies of antibody persistency in healthy adults. We assessed the prevalence and titers of YF virus neutralizing antibodies in previously vaccinated persons aged ≥ 60 years, in comparison to younger adults. We also evaluated the correlation between antibody titers and the time since vaccination among participants who received one vaccine dose, and the seropositivity among participants vaccinated prior to or within the past 10 years. Methods: previously vaccinated healthy persons aged ≥ 18 years were included. YF virus neutralizing antibody titers were determined by means of the 50% Plaque Reduction Neutralization Test. Results: 46 persons aged ≥ 60 years and 48 persons aged 18 to 59 years were enrolled. There was no significant difference in the prevalence of YF virus neutralizing antibodies between the two groups (p = 0.263). However, titers were significantly lower in the elderly (p = 0.022). There was no correlation between YF virus neutralizing antibody titers and the time since vaccination. There was no significant difference in seropositivity among participants vaccinated prior to or within the past 10 years. Conclusions: the clinical relevance of the observed difference in YF virus neutralizing antibody titers between the two groups is not clear.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Aged , Young Adult , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Yellow Fever Vaccine/immunology , Yellow fever virus/immunology , Yellow Fever/prevention & control , Age Factors , Brazil , Immunoglobulin M/blood , Yellow Fever/immunologyABSTRACT
Describes the case of a 6-year-old girl who was stung by a Centruroides testaceus, a scorpion native to the Lesser Antilles, in the Guarulhos International Airport, São Paulo, Brazil, as she disembarked from a flight coming from the Caribbean. The patient presented only local symptoms (a small area of erythema and pain at the sting site), which were resolved after a few hours with analgesics, without the need for antivenom. Physicians who treat patients stung by scorpions should be alert to the possibility of such accidents being caused by non native species, especially those cases that occur near airports or ports.
Descreve-se um caso de menina de 6 anos de idade picada por um Centruroides testaceus, escorpião nativo das Antilhas, no interior do Aeroporto Internacional de Guarulhos, São Paulo, Brasil, após ter desembarcado de um vôo vindo do Caribe. A paciente apresentou apenas sintomas locais (pequena área de eritema e dor no local da picada), resolvidos em algumas horas com uso de analgésicos, não necessitando receber soro antiveneno. Os médicos que tratam pacientes picados por escorpiões devem estar precavidos quanto à possibilidade dos acidentes serem causados por espécies não-nativas, especialmente nos que ocorrem próximos a aeroportos ou portos.
Subject(s)
Animals , Child , Female , Humans , Spider Bites/diagnosis , Scorpions/classification , Spider Bites/etiology , TravelABSTRACT
INTRODUCTION: This study analyses the cases of all bites (including dry bites) caused by Bothropoides jararaca attended at the Vital Brazil Hospital of the Butantan Institute, State of São Paulo, Brazil. METHODS: A retrospective study was conducted of patients bitten by Bothropoides jararaca (n=792) from January 1990 to December 2004. The characteristics of the snake specimen, data related to the accident and clinical manifestations on admission were obtained from patient medical records. RESULTS: The majority of the cases in this study were caused by female and juvenile snakes. No stomach contents were found in 93.4 percent of the snake specimens after dissection. No statistical difference was observed between the occurrence of dry bites and the maturity or sex of the snake. The median SVL of snakes in mild and moderate cases was 40.5cm and in severe cases, SVL increased to 99cm. Necrosis was more common in the digits of the feet and hands (4.8 percent) compared to the other body regions (1.8 percent). A significant difference was verified between severity and a time interval greater than six hours from the bite to hospital admission. A significant association was verified between gingival bleeding and abnormal blood coagulability. In accidents caused by adult snakes, necrosis was more frequent (7.2 percent) compared to accidents caused by juvenile snakes (1 percent). CONCLUSIONS: In this work, the association between certain epidemiological data and the evolution of biological parameters in the clinical course of Bothrops sensu latu accidents were highlighted, contributing to the improvement of snake bite assistance.
INTRODUÇÃO: Neste estudo, analisou-se todos os casos de picadas (incluindo picadas secas) causadas por Bothropoides jararaca atendidos no Hospital Vital Brazil do Instituto Butantan, São Paulo, Brasil. MÉTODOS: Estudo retrospectivo em que foram incluídos pacientes atendidos no Hospital Vital Brazil do Instituto Butantan, picados por serpentes da espécie Bothropoides jararaca (nº=792) entre 1990 a 2004. Os dados foram obtidos através de prontuários médicos. RESULTADOS: No presente estudo, a maioria dos acidentes foi causada por serpentes fêmeas e filhotes. Não havia presença de conteúdo estomacal em 93,4 por cento das serpentes dissecadas. Não houve diferença estatística entre a ocorrência de picada seca e o sexo da serpente. O comprimento rostro cloacal das serpentes nos casos leves e moderados foram 40,5cm e nos casos severos 99cm. Necrose foi mais comum nos dedos dos pés e das mãos (4,8 por cento) em comparação com outras regiões do corpo (1,8 por cento). Houve diferença estatística entre a gravidade e o intervalo de tempo entre a picada e a admissão hospitalar superior a seis horas. Encontramos uma associação significativa entre gengivorragia e incoagulabilidade sanguínea. Nos acidentes causados por serpentes adultas, a necrose foi mais frequente (7,2 por cento) quando comparado aos acidentes causados por serpentes filhotes (1 por cento). CONCLUSÕES: Neste estudo, destaca-se a associação entre os dados epidemiológicos e biológicos em relação à evolução do quadro clínico nos acidentes botrópicos, contribuindo para a melhoria da assistência nos acidentes ofídicos.
Subject(s)
Adult , Aged , Animals , Child , Female , Humans , Male , Bothrops , Snake Bites/epidemiology , Brazil/epidemiology , Retrospective Studies , Seasons , Severity of Illness Index , Snake Bites/pathology , Time FactorsABSTRACT
INTRODUÇÃO: Desde 1930, quando o primeiro caso de sensibilização alérgica a um veneno ofídico foi descrito na literatura, os venenos de todas as principais famílias de serpentes têm sido implicados como causadores de reações alérgicas. O desenvolvimento deste tipo de hipersensibilidade tem sido descrito após recorrentes exposições aos venenos através de picadas e, presumivelmente, de repetidas inalações ou contato desses venenos com a pele ou membranas mucosas. Esta condição tem sido observada entre os profissionais que manuseiam as serpentes e/ou os seus venenos. Entretanto, pouco se conhece a respeito da prevalência dessa doença entre esses trabalhadores, seus determinantes, e natureza molecular dos alérgenos envolvidos. Os objetivos deste estudo foram avaliar a prevalência da alergia ao veneno de Bothrops jararaca, apontando os fatores preditores para o seu desenvolvimento, entre trabalhadores expostos à serpente e/ou ao seu veneno, e demonstrar o envolvimento de um mecanismo IgE-mediado neste tipo de doença ocupacional. MÉTODOS: Sessenta e sete herpetologistas de um instituto de pesquisa, expostos à serpente Bothrops jararaca e/ou ao seu veneno, foram submetidos a um questionário e a testes imunológicos, para avaliar a presença de alergia ao veneno. A sensibilização ao veneno foi determinada pela quantificação de anticorpos da classe IgG e IgE, específicos ao veneno de Bothrops jararaca, através dos testes sorológicos ImmunoCAP e ELISA. Os alérgenos foram caracterizados através de Western blotting e de ensaios de inibição do ImmunoCAP. RESULTADOS: Doze dos 67 trabalhadores reportaram sintomas alérgicos variando desde urticária, rinoconjuntivite e asma, até anafilaxia. Sete indivíduos apresentaram anticorpos IgE específicos ao veneno de Bothrops jararaca (prevalência = 10,4%). Destes, seis apresentavam sintomas clássicos de reações alérgicas IgE-mediadas, quando expostos ao veneno botrópico...
BACKGROUND: Allergic sensitization to snake venom was first reported in 1930 and since that time, venoms from the major snake families have been implicated as cause of allergic reactions. The development of hypersensitivity to snake venom has been described after recurrent exposure through bites and, presumably, through repeated inhalations or repeated contact of the venom with skin or mucous membranes. This condition has been observed in amateur and professional snake handlers. However, only limited information is available on the prevalence of the disease among those workers, their determinants and the molecular nature of these allergens. The aim of this study was to evaluate the prevalence and the predictors of snake venom allergy among workers exposed to Bothrops jararaca venom and to demonstrate the involvement of IgE-mediated mechanisms in this occupational disease. METHODS: Sixty seven workers exposed to Bothrops jararaca snakes and/or their venoms in a research institute were assessed for snake venom-related allergy using questionnaires and immunological tests. Presence of snake venom sensitization was determined by quantification of specific IgE and IgG to Bothrops jararaca venom using the UniCAP® system and ELISA. Allergens were characterized by Western blotting and ImmunoCAP inhibition assays. RESULTS: Twelve of the 67 workers experienced symptoms ranging from urticaria, rhinoconjuctivitis and asthma to anaphylaxis. Seven individuals had specific IgE antibodies to Bothrops jararaca snake venom (prevalence = 10,4%). Six of them had typical symptoms of an IgE-mediated allergic reaction when exposed to Bothrops venom. Specific IgG antibodies could also be observed in sensitized individuals. High levels of total IgE (p=0,034), exposure level (p=0,042), handling of dried venom (p=0,014) and personal history of atopy (p=0,051) could be demonstrated as predictors for sensitization...