ABSTRACT
Toxocariasis is an important, but neglected, worldwide zoonosis. It is considered a primarily soil-transmitted disease, but food-borne transmission has been associated with the consumption either of raw or undercooked meat of paratenic hosts, including birds. Despite the number of experimental studies carried out to evaluate the behavior of Toxocara spp. larvae in birds, their role in the dispersion of eggs into the environment remains unclear. Thus, this study aimed to evaluate the potential of broiler chickens to release Toxocara canis eggs into the environment, and the infectivity of eggs after passage through the intestine. Forty commercial broiler chickens, aged 60 days, were randomly distributed into three groups. Groups 1 (n = 16) and 2 (n = 16) were orally infected with 5000 embryonated and 5000 unembryonated T. canis eggs, respectively. Group 3 (n = 8) served as a control. Following infection, fecal samples from each chicken were examined using a centrifuge-sedimentation technique. At 24-h, 72-h, and 7-day post-infection (PI), four chickens each from the G1 and G2 groups, and two from the G3 group were killed. After euthanasia, the intestinal content and liver were collected for recovery of T. canis larvae. Results revealed that broiler chickens have the potential to disperse both embryonated and unembryonated T. canis eggs, following 2- to 6-h PI. In addition, the eggs shed into the feces of the G2 birds, after incubation in laboratorial conditions, were infective when they were tested in a bioassay using mice. In conclusion, broiler chickens have the potential of dispersing Toxocara spp. eggs into the environment and the eggs passed through the intestine are infective after being incubated in experimental conditions.
Subject(s)
Chickens/parasitology , Intestines/parasitology , Larva/pathogenicity , Ovum/cytology , Toxocara canis/pathogenicity , Toxocariasis/parasitology , Animals , Feces/parasitology , Female , Liver/parasitology , Mice , Poultry Diseases/parasitology , Soil/parasitologyABSTRACT
A toxocaríase humana é uma infecção parasitária de distribuição mundial causada pelos nematelmintos das espécies Toxocara canis e Toxocara cati, presentes no intestino do cão e do gato, respectivamente. Clinicamente, na maioria das vezes, é assintomática, porém pode apresentar-se de duas formas: visceral ou ocular. Visceralmente, gera uma síndrome hipereosinofílica crônica, acompanhada por leucocitose e hepatomegalia, podendo ocorrer algum grau de infiltrado pulmonar e febre. Na toxocaríase ocular, ocorre uveite intermediária ou posterior, podendo haver formação de granuloma, geralmente unilateral. O acometimento misto é raro, o que motivou este relato. Trata-se de paciente de 19 anos, sexo masculino, que apresentou como sintoma inicial perda da acuidade visual em olho esquerdo. Recebeu tratamento, sem melhora, com sulfametoxazol + trimetoprima e corticoide, fazendo farmacodermia. Evoluiu com diarreia, febre, dor abdominal e hepatoesplenomegalia. Descartadas infecções agudas por toxoplasmose, sífilis, vírus da imunodeficiência humana (HIV), citomegalovirose e dengue; apresentou leucocitose com hipereosinofilia. Foi solicitada sorologia para toxocaríase, confirmando esta infecção. Após o tratamento, apresentou completa remissão dos sintomas. O objetivo aqui foi debater os fatores confundidores, diagnósticos diferenciais, necessidade de exames complementares específicos e conduta terapêutica, de acordo com o quadro clínico.(AU)
Human toxocariasis is a worldwide parasitic infection caused by ascarid nematodes species: Toxocara canis and Toxocara cati, that are present in the intestines of dogs and cats, respectively. Although clinically, most human infections are asymptomatic, two syndromes of human toxocariasis are recognized: visceral and ocular. The visceral form is a hypereosinophilic syndrome accompanied by leukocytosis, hepatomegaly, some degree of pulmonary infiltrate and fever. In ocular toxacariasis there is intermediate or posterior uveitis, and there may be granuloma formation, usually unilateral. The simultaneous involvement of the two forms is rare, which is what, motivated this report. It is a 19-year-old male patient who initially presented loss of visual acuity in the left eye. He received treatment, without improvement, with sulfamethoxazole-trimethoprim and corticoid, causing a pharmacodermia. He developed diarrhea, fever, abdominal pain and hepatosplenomegaly. It was discarded acute infections by toxoplasmosis, syphilis, human immunodeficiency virus (HIV), cytomegalovirus and dengue. The patient also manifested leukocytosis with hypereosinophilia. Serological testing for toxacariasis was requested, diagnosing the infection. After treatment, he progressed with full symptoms remission. The aim of this study was to discuss confounding factors, differential diagnoses, the need for specific complementary exams and therapeutic management, according to the clinical aspects.(AU)
Subject(s)
Humans , Male , Young Adult , Toxocara canis/pathogenicity , Toxocariasis , Toxoplasmosis, Ocular/diagnosis , Toxoplasmosis, Ocular/drug therapy , Uveitis/diagnosis , Uveitis/drug therapyABSTRACT
INTRODUÇÃO: Toxocaríase é uma infecção parasitária de distribuição global, causada pela fase larval de Toxocara spp. Os hospedeiros naturais são cães e gatos, nos quais o parasita completa o ciclo chegando a fase adulta. Outros hospedeiros podem ser infectados pela fase larval do parasita, após ingestão de ovos embrionados do solo, mãos contaminadas, fomites, ou ingestão de carne ou vísceras de animais infectados. Em hospedeiros paratênicos o parasita não completa o ciclo, invadindo em estágio larval vísceras ou outros tecidos, onde podem sobreviver e induzir a patologia. O presente estudo teve como objetivo caracterizar o hamster (Mesocricetus auratus), como modelo experimental de toxocaríase, inicialmente através do estudo das lesões histopatológicas em fígado, pulmão e rim. A caracterização da resposta imunológica do modelo, foi feita através do estudo de citocinas envolvidas nas respostas Th1 e Th2, e foi sugerida uma correlação entre alterações glomerulares e depósitos de complexos antígenos-anticorpo pré-formados na circulação. MÉTODOS: Hamsters foram inoculados com ovos embrionados de Toxocara canis, e mantidos no biotério do Instituto de Medicina Tropical de São Paulo. O estudo histopatológico foi desenvolvido utilizando-se cortes parafinados corados por hematoxilina e eosina. Para detecção de antígenos nos tecidos foram realizadas reações imunohistoquímicas, utilizando-se anticorpo monoclonal e policlonal anti- Toxocara canis. Utilizando-se o soro dos animais infectados e animais controle, foi realizada pesquisa de antígeno e anticorpo por ELISA. Para pesquisa de imunoglobulinas IgG e IgM e complemento, foram utilizados cortes congelados de rins para realização de reação de Imunofluorescência. Fragmentos de rins foram incluídos para utilização em microscopia eletrônica, para detecção de antígenos de toxocara e de imune complexos. Para caracterização de resposta imunológica foram estudadas citocinas envolvidas na resposta Th1 e Th2 por técnica de...
INTRODUCTION: Toxocariasis is a parasitic infection of global distribution, caused by the larval stage of Toxocara spp. The natural hosts are dogs and cats, in which the parasite completes the cycle reaching adulthood. Other hosts can be infected with the larval stage of the parasite, after ingestion of embryonated eggs from the soil, contaminated hands, fomites, or ingestion of meat or viscera of infected animals. In paratenics hosts the parasite not complete the cycle, encroaching on larval stage in viscera or other tissues where they can survive and induce pathology. The present study aimed to characterize the hamster, Mesocricetus auratus, as experimental model of toxocariasis, initially through the study of histopathological lesions in the liver, lung and kidney. The characterization of immune response model, was made through the study of cytokines Th1 and Th2 responses involved, and a correlation was suggested between glomerular changes and antibody-antigen complexes deposits preformed in the circulation. METHODS: Hamsters were inoculated with embryonated eggs of Toxocara canis, and kept in the bioterium of the Institute of Tropical Medicine of the São Paulo. The histopathologic study was developed using paraffin slides stained by hematoxylin and eosin. For detection of antigens in tissues immunohistochemistry reactions were performed using monoclonal and polyclonal anti-Toxocara canis sera. Using the serum of infected and control animals, search has been carried out of antigen and antibody by ELISA. For the search of immunoglobulins IgG, IgM and complement, were used slides prepared from frozen fragments of kidneys and a immunofluorescence reaction. Fragments of kidneys were included for electron microscopy to detect antigens of Toxocara and immune complexes. For characterization of Th1 and Th2 response cytokines involved were detected by RT-PCR technique. RESULTS: Histopathological findings demonstrated since the beginning of the...
Subject(s)
Animals , Cats , Dogs , Rats , Glomerulonephritis , Infections/parasitology , Kidney Diseases , Larva Migrans, Visceral , Antigen-Antibody Reactions/immunology , Toxocara canis/pathogenicity , Toxocariasis/parasitology , Models, Animal , Mesocricetus/methodsABSTRACT
Visceral toxocariasis is a serious public health problem with a cosmopolitan distribution. Children are susceptible due to their immature immune system and high risks of infection. Nevertheless, the few completed studies about immunosuppression have had controversial results. To evaluate the effect of two immunosuppressive drugs on the larval burden of Toxocara canis, four groups of ten Swiss strain mice each were inoculated on day 0 with 1,200 embryonated T. canis eggs. Fifteen days before the experimental infection, group 1 (control) was treated via intraperitoneal injection (IP) with sterile distilled water and groups 2 and 3 were treated with dexamethasone (DEX) at 1 and 5 mg/kg/day, respectively. Additionally, group 4 was treated IP with cyclophosphamide (CY) at 50 mg/kg at two times per week for 2 weeks. Sixty days following infection, the mice were euthanised to recover the larvae by means of the tissue digestion technique. The levels of antibodies detected by indirect ELISA were not associated with the larval burden. Administration of CY (50 mg/kg) and DEX (5 mg/kg) resulted in an increase of the larval burden of 162.1% and 50.8%, respectively, in relation to the control group. These two treatments, especially CY (50 mg/kg), promoted immunosuppression and the establishment of a significant larval burden, supporting its further utilisation in studies related to immunosuppression in visceral toxocariasis.
Subject(s)
Cyclophosphamide/administration & dosage , Dexamethasone/administration & dosage , Immunosuppressive Agents/administration & dosage , Toxocara canis/immunology , Toxocara canis/pathogenicity , Toxocariasis/immunology , Toxocariasis/parasitology , Animal Structures/parasitology , Animals , Female , Larva/immunology , Larva/pathogenicity , Mice , Parasite Load , Toxocara canis/isolation & purificationABSTRACT
BACKGROUND: It has been suggested that the presence of Toxocara canis larvae in lungs is an underlying factor in the onset of asthma. Although the association of asthma and seropositivity to Toxocara has been observed, there are no studies that indicate whether these antibodies are specific against T. canis antigens. METHODS: Seroprevalence to T. canis excretion-secretion antigens (TcES Ag) were compared between asthmatic children (n=285) and non-asthmatic children (n=152), using IgG-ELISA and IgE-ELISA. The recognition patterns of TcES Ag were determined using Western blot (WB). RESULTS: IgG-ELISA seroprevalence was 30.8% for asthmatic children and 19.7% for non-asthmatic children (p<0.05). IgE-ELISA seroprevalence was 7.7% for asthmatic children and 6.5% for non-asthmatic children, respectively (p>0.05). Sera of both groups positive to IgG-ELISA recognised 11 TcES Ag bands for IgG. No differences between the groups were observed regarding recognition patterns; the asthmatic group, however, presented significantly higher cross-reaction to Ascaris suum somatic antigens (AsS Ag) than the non-asthmatic group. Sixty-three sera from asthmatic children positive to IgG-ELISA were evaluated by WB for IgE and 58.7% revealed a recognition pattern for IgE. In the group of non-asthmatic children positive to IgG-ELISA, 80% presented IgE band recognition. No differences were observed between the groups regarding recognition patterns. CONCLUSIONS: The results observed suggest that differences in seroprevalence determined by IgG-ELISA between groups of asthmatic and non-asthmatic children reported by other authors occur because of a higher frequency of cross-reaction in asthmatic children.
Subject(s)
Ascaris suum/immunology , Asthma/immunology , Toxocara canis/immunology , Toxocariasis/immunology , Animals , Antigens, Helminth/immunology , Asthma/blood , Asthma/epidemiology , Asthma/physiopathology , Child , Child, Preschool , Cross Reactions , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin E/blood , Immunoglobulin G/blood , Male , Mexico , Seroepidemiologic Studies , Toxocara canis/pathogenicity , Toxocariasis/blood , Toxocariasis/epidemiology , Toxocariasis/physiopathologyABSTRACT
Survival of parasitic helminths within a host requires immune evasion and excretory/secretory (ES) proteins may contribute to this process. Eosinophils are important effector cells in immunity of mice to the nematode Nippostrongylus brasiliensis and eosinophilic interleukin-5 transgenic (IL-5 Tg) mice are highly resistant to the earliest stages of primary infections. In contrast, Toxocara canis is largely resistant to eosinophils, with viable larvae encysted in tissues often surrounded by these and other leucocytes. The aim of this study was to investigate whether T. canis ES (TES) proteins inhibit eosinophil-dependent resistance to N. brasiliensis. Mouse serum pre-treated with TES had reduced capacity to mediate the adherence of leucocytes to N. brasiliensis infective-stage larvae (L3) and this correlated with reduced complement C3 deposition on the parasite. TES did not inhibit eosinophil survival or eotaxin-dependent eosinophil migration in vitro. Cellular inflammation and eosinophil degranulation in the skin in response to injection of L3 was also not impaired by TES. However, when TES was included with L3 in an inoculum given to IL-5 Tg mice, a greatly increased number of parasites migrated to the lung. This suggests that the early eosinophil-dependent resistance in these mice was suppressed, by mechanisms yet to be determined.
Subject(s)
Eosinophils/drug effects , Eosinophils/immunology , Helminth Proteins/toxicity , Immune Evasion , Nippostrongylus/immunology , Nippostrongylus/pathogenicity , Toxocara canis/pathogenicity , Animals , Female , Lung/parasitology , Lung/pathology , Male , Mice , Skin/parasitology , Skin/pathologyABSTRACT
La toxocarosis es un problema sanitario presente en todo el mundo. Sin embargo, por tratarse de una patología que no es de notificación obligatoria y por la existencia de casos asintomáticos, las cifras de prevalencia real en Argentina no son bien conocidas y por ello la toxocariasis tiene un escaso reconocimiento como problema de salud pública. El objetivo del presente trabajo fue determinar la seroprevalencia en adultos sanos de una ciudad subtropical del Nor-Este de Argentina, en la que estudios previos indican que la infección infantil por Toxocara canis es frecuente y que la contaminación de suelos está presente. Se estudiaron 355 sueros de donantes de sangre (325 hombres y 30 mujeres), con edades entre 18 y 68 años, de un Banco de Sangre privado de la ciudad de Resistencia. Se efectuó enzimoinmunoensayo empleando antígenos de excresión/secresión de larvas L2 de T. canis confirmándose mediante Western blot. De los 355 sueros estudiados, 138 fueron positivos (127 hombres y 11 mujeres), lo que significa una prevalencia global de infección del 38,9 por ciento; no se encontró diferencia significativa en relación con el género (39,1 por ciento en hombres - 36,7 por ciento en mujeres). Como el muestreo correspondió íntegramente a población adulta, no se consideró de interés discriminar los valores de positividad según franjas etarias. Los resultados encontrados resultan compatibles con las características urbanas y ambientales del área del estudio y con los hábitos socio-culturales de sus habitantes, y señalan una fuerte presencia del ascárido, con un importante grado de exposición por parte de sus pobladores.
Subject(s)
Adult , Risk Factors , Toxocara canis/pathogenicity , Toxocariasis/epidemiology , Toxocariasis/transmission , Argentina/epidemiology , Seroepidemiologic StudiesABSTRACT
La toxocarosis es una parasitosis producida por los nematodos Toxocara canis y Toxocara felis cuyos huéspedes naturales son los cánidos y félidos domésticos, respectivamente. La infección humana ocurre de manera accidental por la ingesta de huevos larvados presentes en la tierra, arena, agua o alimentos contaminados. Abarca una diversidad de presentaciones clínicas que sumadas a la inespecifidad de la sintomatología y a la dificultad para acceder a un diagnóstico de laboratorio preciso, lleva a que la mayoría de los profesionales no piensen en esta helmintiasis. EL presente trabajo describe un caso clínico de toxocarosis neurológica, diagnóstica, tratamiento y epidemiología. Paciente femenino de 42 años de edad, con historia de contacto íntimo con cachorros y perras preñadas que desarrolló compromisos neurológicos (paraparesia y vejiga neurógena espástica) asociada a leucocitosis con eosinofilia intensa y persiste (11.766 eosinófilos/mm3), hepatomegalia y serología positiva a Toxocara canis determinada por Elisa y confirmada por Western-blot. Tratamiento: albendazol 400 mg/ día cada 12 hs por vía oral durante 7 días y metilprednisona 80 mg/ día por vía oral durante 3 semanas seguidas de una disminución paulatina de la dosis. El estudio epidemiológico consistió en diagnóstico serológico a convivientes de la paciente, análisis parasitológicos a las heces de su perro y a muestras de tierra procedentes de su domicilio, resultando en todos casos positivos para Toxocara canis
Subject(s)
Humans , Female , Adult , Paraparesis/etiology , Toxocara canis/pathogenicity , Toxocariasis/diagnosis , Urinary Bladder, Neurogenic/etiology , Albendazole/therapeutic use , Animals, Domestic/parasitology , Disease Reservoirs , Feces/parasitology , Methylprednisolone/therapeutic use , Parasite Egg Count , Serologic Tests , Toxocara canis/drug effects , Toxocara canis/isolation & purification , Toxocariasis/drug therapy , Toxocariasis/epidemiology , Toxocariasis/transmissionABSTRACT
This study consisted of a stratified sampling, randomly taken, of the soil from the squares and parks of the city of La Plata, Province de Buenos Aires, in order to establish the prevalence of contamination caused by Toxocara sp. A total 242 soil samples was examined. From each sample a 10 grams aliquot was taken, washed in a 0.2 percent Tween 80 solution, and processed using the technique of concentration by flotation with sugar solution. There was a prevalence of 13.2 percent. In each positive sample, the quantity of eggs varied from 1 to 4. Toxocara sp. eggs were observed in 15 out of 22 squares and parks investigated. The sampling design and the processing method employed were satisfactory for the recovering and identification of Toxocara sp. eggs
Subject(s)
Humans , Animals , Recreational Zones , Environmental Pollution , Toxocara canis/isolation & purification , Animals, Domestic/parasitology , Argentina/epidemiology , Parasite Egg Count , Prevalence , Soil Pollutants/isolation & purification , Stratified Sampling , Toxocara canis/pathogenicity , Toxocariasis/epidemiologyABSTRACT
The relationship between asthma and covert toxocariasis was studied in 38 patients with asthma and 44 control individuals (without asthma). Inclusion/exclusion criteria were determined. An ELISA test based on the detection of Anti-Toxocara canis (E/S antigen) serum immunoglobulin G (Ig G) and E (Ig E) was determined in both groups. Ordinary allergens and E/S antigen of T. canis injections were used to evaluate cutaneous reactivity. The seroprevalence in patients with asthma was 68.42%, and in the control individuals was 13.63%. This difference was significant. The percentage of asthmatic patients with two antitoxocara antibodies was 26.31% and 4.54% in control individuals. All asthmatic patients with antitoxocara IgE had cutaneous reactivity to Ag E/S. We conclude that the asthmatic patients with IgE and IgG antitoxocara suffer a covert toxocarosis.
Subject(s)
Antibodies, Helminth/analysis , Asthma/complications , Toxocariasis/complications , Adult , Animals , Asthma/diagnosis , Asthma/immunology , Biomarkers/blood , Female , Humans , Hypersensitivity , Immunoglobulin E/blood , Immunoglobulin G/blood , Male , Middle Aged , Toxocara canis/pathogenicity , Toxocariasis/diagnosis , Toxocariasis/immunologyABSTRACT
A associaçäo entre o abscesso hepático e a esquistosomose mansônica foi confirmada por estudos clínicos e experimentais. Outros parasitos, como a larva de Toxocara canis, podem causar alteraçöes imunológicas sistêmicas e estruturais nos órgaos acometidos que favorecem a instalaçäo e o crescimento da bactéria. A piomiosite tropical, o abscesso hepático piogênico e o abscesso renal säo doenças freqüentes nos países tropicais e muitas vezes näo se encontra doença de base que poderia explicá-las. A síndrome de larva migrans visceral é causada pela presença no organismo humano de larvas de vermes que têm outros animais como hospedeiro definitivo sendo a T. canis o agente mais comum. As larvas migram por vários órgäos causando reaçäo inflamatória na forma de granuloma com necrose tecidual. Nesta revisäo discutem-se os possíveis mecanismos de interaçäo entre o hospedeiro, o parasito e a bactéria que podem favorecer a formaçäo de abscessos nos órgäos acometidos pela larva de T. canis e resumem-se alguns resultados preliminares de trabalho clínico-experimental realizado durante os últimos quatro anos para definir o papel deste parasito na patogenia dos abscessos
Subject(s)
Humans , Male , Female , Liver Abscess/etiology , Kidney/microbiology , Larva Migrans, Visceral , Myositis/etiology , Staphylococcal Infections , Toxocara canis/pathogenicity , Toxocariasis , Host-Parasite Interactions , Staphylococcus aureusABSTRACT
A 24-year -old woman 2-3 months after a normal parturation presented geophagy. Due to hypermenorrhea she consulted a gynecologist and in a hemogram a 57 percent (6, 893 x mm3) hypereosinophilia was detected. A chest TAC showed bilateral pulmonary nodules. The following tests resulted positive: ELISA IgG for toxocariasis 1: 1000, isohemagglutinins anti A 1:2048 and anti B 1:512. The patient was treated with albendazole and prednisone during 10 days. One month after treatment eosinophilia decreased to 2.590 x mm3 and ELISA IgG for toxocariasis descended to 1:128. Different aspect of human toxocariasis are commented. When hypereosinophia is observed in adult patients, toxocariasis must be checked
Subject(s)
Humans , Female , Adult , Granuloma/etiology , Larva Migrans, Visceral/complications , Hypereosinophilic Syndrome/etiology , Albendazole/therapeutic use , Enzyme-Linked Immunosorbent Assay , Larva Migrans, Visceral/diagnosis , Larva Migrans, Visceral/drug therapy , Larva Migrans, Visceral/etiology , Prednisone/therapeutic use , Toxocara canis/isolation & purification , Toxocara canis/pathogenicity , Toxocariasis/etiologySubject(s)
Humans , Infant, Newborn , Infant , Child, Preschool , Child , Eosinophilia/classification , Eosinophilia/diagnosis , Eosinophilia/etiology , Toxocara canis/pathogenicity , Toxocariasis/diagnosis , Toxocariasis/drug therapy , Thiabendazole/administration & dosage , Thiabendazole/therapeutic use , Hypereosinophilic Syndrome/physiopathology , Hypereosinophilic Syndrome/diagnosisSubject(s)
Humans , Infant, Newborn , Infant , Child, Preschool , Child , Eosinophilia/classification , Eosinophilia/diagnosis , Eosinophilia/etiology , Hypereosinophilic Syndrome/diagnosis , Hypereosinophilic Syndrome/physiopathology , Thiabendazole , Thiabendazole/therapeutic use , Toxocara canis/pathogenicity , Toxocariasis/diagnosis , Toxocariasis/drug therapyABSTRACT
La toxocariasis es una infección por un nematodo que tiene dos formas clínicas de manifestarse: larva migrans visceral y toxocariasis ocular. estas últimas es casi exclusivamente unilateral y típica de la edad infantil; sin embargo, se ha descrito en individuos desde los 2 a los 40 años de edad. Puede presentarse con disminución de la visión, estrabismo, leucocoria o uveítis. Más frecuente es la presencia de un granuloma subrretiano en el polo posterior, o bien un granuloma coriorretiniano periférico. Menos frecuente es la existencia de una endoftalmitis con desprendimiento de retina. Las tres formas de afección ocular presentan las mismas patogenia. Presentamos dos casos clínicos correspondientes a un granuloma coriorretiniano periférico en un varón de 42 años de edad, y a un granuloma de polo posterior en un varón de 29 años. En ambos pacientes el diagnóstico se realizó fundamentalmente por los signos y síntomas, el aspecto clínico típico del fondo de ojo y los antecedentes personales
Subject(s)
Humans , Male , Adult , Eye Infections/etiology , Granuloma/etiology , Toxocariasis/complications , Endophthalmitis/etiology , Eye Infections/diagnosis , Granuloma/diagnosis , Larva Migrans/etiology , Toxocara canis/pathogenicity , Toxocariasis/diagnosis , Toxocariasis/etiology , Uveitis/etiologyABSTRACT
Realizou-se um estudo clínico-epidemiológico envolvendo 471 escolares de 7 a 14 anos de idade do Município de Rio Acima - Regiäo Metropolitana de Belo Horizonte, com o objetivo de se avaliar parâmetros clínicos, oftalmológicos, laboratoriais e epidemiológicos correlacionados com a toxocaríase. Procurou-se estabelecer associaçöes entre essas variáveis e a soropositividade para Toxocara canis, determinando-se os fatores de risco envolvidos na doença. Foi, ainda, avaliada a saúde oftalmológica dessa populaçäo e a prevalência de sorologia positiva para toxoplasmose. O nível de significância adotado foi de 0,05 para os testes estatísticos efetuados. A prevalência de soropositividade para toxocaríase foi determinada em 300 dessas crianças pelo método de ELISA, tendo sido encontrada uma taxa de 7,0 por cento, considerando-se positivos os títulos de anticorpos (IgG) maiores ou iguais a 1:20. A soropositividade se associou significativamente ao contato extradomiciliar recente com filhotes de cäo (p= 0,025, OR = 2,89), à residência em zona urbana central (p= 0,023, OR = 2,83) e ao trabalho extradomiciliar da mäe (p= 0,001, OR = 4,83). Essas associaçöes foram confirmadas por análise de regressäo logística multivariada. Encontrou-se também associaçäo significativa entre a soropositividade e o contato com águas naturais (p= 0,003) mas, como essa variável também estava associada ao contato extradomiciliar recente com filhotes de cäo (p= 0,004) e ao trabalho extradomiciliar da mäe (p=0,003), näo pôde ser considerada fator de risco para a toxocaríase. O mesmo aconteceu em relaçäo ao contato extradomiciliar recente com filhote de gato, que embora tenha se associado à positividade para toxocaríase (p= 0,014), também se associou ao contato extradomiciliar recente com filhotes de cäo (p=0,004). A soropositividade também se associou ao maior nível de escolaridade materna (p= 0,008), mas essa variável também estava associada ao trabalho extradomiciliar da mäe (p= 0,003), näo podendo ser considerada fator de risco para a toxocaríase. Näo foi observada associaçäo significativa entre a sorologia para toxocaríase e o sexo, idade, cor das crianças e as variáveis indicativas de nível socioeconômico (presença de água encanada, rede de esgoto, luz elétrica e número de bens de consumo no domicílio). A presença de cäo adulto ou filhote no domicílio também näo se associou à soropositividade. Essa associaçäo também näo foi encontrada em relaçäo à presença de gato no domicílio. Outra variável que também näo se associou à sorologia positiva para toxocaríase foi o relato de contato com terra e/ou geofagia atual ou pregressa. Também näo se observou associaçäo significativa entre a sorologia para toxocaríase e o relato de quadro clínico compatível com larva migrans visceral no ano anterior à pesquisa, nem com as alteraçöes clínicas ou laboratoriais encontradas (hepatomegalia, esplenomegalia, palidez cutânea, leucocitose, eosinofilia e ascaridíase intestinal). A prevalência de sorologia positiva para Toxoplasma gondii entre as 300 crianças estudadas, pelo método de imunofluorescência indireta, foi de 56 por cento considerando-se positivos os títulos de IgG iguais ou maiores do que 1:16. O exame oftalmológico, realizado nas 471 crianças e constituído de medida da acuidade visual monocular, "cover test", inspeçäo do segmento anterior dos olhos e das pálpebras, tonometria e oftalmoscopia binocular indireta, detectou baixa acuidade visual em 2,5 por cento das crianças, estrabismos em 1,5 por cento, alteraçöes fundoscópicas responsáveis por diminuiçäo da acuidade visual em 0,6 por cento, catarata congênita em 0,4 por cento. Näo foram encontrados sinais oftalmológicos compatíveis com as formas conhecidas de toxocaríase ocular entre os 471 escolares examinados.
Subject(s)
Humans , Child , Adolescent , Eye Diseases/pathology , Students , Toxocariasis/epidemiology , Academic Dissertation , Enzyme-Linked Immunosorbent Assay , Eye Diseases/etiology , Larva Migrans/pathology , Retrospective Studies , Serologic Tests , Toxocara canis/pathogenicityABSTRACT
Se realiza una Síntesis Bibliográfica sobre el síndrome de larva migrante visceral provocado por toxocara cani. Dado que es una patología que se está diagnosticando y tratando hace pocos años en nuestro país y hay poca información del punto de vista epidemiológico, se considera de importancia transmitir este conocimiento a la comunidad, dado que la prevención primaria es muy importante