Toxocaríase: larva migrans visceral em crianças e adolescentes / Toxocariasis: visceral larva migrans in children

OBJETIVOS: Apresentar investigação detalhada de fatores de risco, sintomatologia, exames laboratoriais e de imagem que possam contribuir para o diagnóstico clínico-laboratorial da larva migrans visceral (LMV) em crianças e mostrar a importância do diagnóstico e do tratamento para evitar complicações oculares, hepáticas e em outros órgãos. FONTES DOS DADOS: Revisão de literatura utilizando os bancos de dados MEDLINE e LILACS (1952-2009), selecionando os artigos mais atuais e representativos do tema. SÍNTESE DOS DADOS: LMV é uma doença infecciosa de apresentação clínica inespecífica cuja transmissão está relacionada ao contato com cães, principalmente filhotes, podendo evoluir com complicações sistêmicas tardias em órgãos vitais como o olho e sistema nervoso central. Para diagnóstico laboratorial, pode ser utilizado IgG (ELISA) anti-Toxocara canis, cujos pontos de corte mais elevados sugerem doença recente e, os mais baixos, infecção leve ou em resolução. A resposta terapêutica pode ser avaliada por meio da contagem de eosinófilos no sangue. Esse artigo atualiza o pediatra em relação à LMV, doença de alta prevalência no mundo e no Brasil. CONCLUSÕES: O diagnóstico de LMV depende principalmente da epidemiologia da presença de cães no domicílio da criança, associada ao ELISA (IgG para T. canis), utilizando antígenos Toxocara de excreção e secreção. São necessários estudos prospectivos para avaliar a melhor droga na terapêutica. A prevenção é a estratégia mais importante devido à alta prevalência de T. canis na região urbana.

OBJECTIVES: To present a detailed investigation of risk factors, symptoms, and laboratory and imaging tests that may be useful to establish the clinical laboratory diagnosis of visceral larva migrans (VLM) in children, demonstrating the importance of diagnosis and treatment to prevent complications in the eyes, liver, and other organs. SOURCES: Literature review using the MEDLINE and LILACS (1952-2009) databases, selecting the most recent and representative articles on the topic. SUMMARY OF THE FINDINGS: VLM is an infectious disease with non-specific clinical presentation, whose transmission is related to contact with dogs, especially puppies, and which may progress to late systemic complications in vital organs such as the eyes and the central nervous system. IgG (ELISA) anti-T. canis can be used to establish the laboratory diagnosis. Higher cutoff points suggest recent illness and lower cutoff points demonstrate mild infection or infection in remission. Therapeutic response may be assessed by means of eosinophil blood cell count. The present article provides the pediatrician with updated information regarding VLM, a disease of high prevalence worldwide and in Brazil. CONCLUSIONS: The diagnosis of VLM depends mainly on the presence of dogs in the child's household, associated with ELISA (IgG anti-T. canis), using excretory-secretory antigens of Toxocara canis. Prospective studies are warranted to assess the best drug therapy. Prevention is the most important strategy because of the high prevalence of T. canis in urban areas.

MRI findings of spinal visceral larva migrans of Toxocara canis.

PURPOSE: The purpose of this study is to investigate the MRI findings of visceral larva migrans (VLS) of Toxocara canis in spinal cord. MATERIALS AND METHODS: We retrospectively reviewed spinal MRI findings in eight patients with serologically proven Toxocara canis between 2005 and 2008. We evaluated the location, length, extent and migration of the lesion, MR signal intensity (SI), enhancement pattern, and swelling of the spinal cord. We evaluated clinical features including presenting symptoms and signs and treatment response. RESULTS: Total 8 patients (M=8; age range 36-79 years) were included. The lesions were located in the cervical or thoracic spinal cord in all patients. All lesions showed high SI and minimal or mild swelling of involved spinal cord on T2WI and focal nodular enhancement on posterior or posterolateral segment of spinal cord. The length of involved lesion was relatively short in most patients. There was a migration of lesion in one patient. In spite of albendazole or steroid treatment, neurological symptoms or signs were not significantly improved in all patients. CONCLUSION: Although all lesions show non-specific imaging findings like non-tumorous myelopathy mimicking transverse myelitis, single lesion, focal nodular enhancement on posterior or posterolateral segment of spinal cord, relatively short segmental involvement and migration of lesion may be characteristic findings of spinal VLM of Toxocara canis. In addition, the reluctant response to the treatment may be characteristic of spinal VLM of Toxocara canis.

Pulmonary toxocariasis masquerading as metastatic tumor nodules in a child with osteosarcoma.

A 14-year-old male, who completed chemotherapy following limb salvage surgery for osteosarcoma approximately 2 years ago, was seen for routine follow-up. A CT scan revealed new scattered multifocal nodular lesions. An ultrasonography-guided percutaneous needle biopsy was done to confirm pulmonary metastasis of the underlying osteosarcoma. The lung biopsy showed findings of eosinophilic pneumonia with no evidence of malignancy. Peripheral eosinophilia was also noted. When a more thorough history revealed frequent intake of raw cow liver, we diagnosed pulmonary toxocariasis by ELISA for specific serum IgG antibody.

[Toxocariasis as a cause of hypereosinophilia].

Toxocariasis is one of the causes of eosinophilia in peripheral blood and provokes eosinophilic infiltration in internal organs. In Israel, the number of cases of toxocariasis is very low, 3 cases annually, according to the records at the Ministry of Health. Many cases of eosinophilia might be misdiagnosed as hypereosinophilia syndrome (HES), if serological testing for Toxocara is not conducted, leading to inappropriate treatment. The test is for specific serum IgG antibody of Toxocara canis antigen measured by enzyme-linked immunosorbent assay (ELISA). The authors present a 4 year old girl with hypereosinophilia of 40,000 cell/microl, without involvement of target organs. The authors found that toxocara was the cause of hypereosinophilia. After appropriate treatment the number of eosinophils decreases, presenting a measurement of the parasite activity.

Contaminação por fezes caninas das praças públicas de Cuiabá, Mato Grosso / Contamination for faecal samples dogs of the public squares of Cuiabá, Mato Grosso

O presente trabalho teve o objetivo de avaliar a contaminação das praças públicas de Cuiabá, Estado de Mato Grosso, por fezes de cães. Foram pesquisadas 55 praças, de agosto a novembro de 2006. Destas, 14 localizavam-se no centro da cidade e 41 em diversos bairros periféricos do município. As amostras foram coletadas pela manhã, armazenadas em sacos plásticos sob refrigeração e processadas no Laboratório de Doenças Parasitárias do Hospital Veterinário da UFMT, através das técnicas de Willis-Mollay e Hoffmann, Pons e Janer, 1934. Das 55 praças, 40 possuíam amostras de fezes de cães. Ao todo foram coletadas 121 amostras e em 45 foram observados ovos de helmintos. Destas, 38 (84,4%) apresentaram ovos de Ancylostoma sp; 07 (15,5%) de Toxocara sp; 09 (20%) de Trichuris vulpis e 01 (2,2%) de Platynossomum sp e Cystoisospora sp. Vinte e duas das 121 amostras encontradas foram nas praças centrais e 99 nas de bairros periféricos, entretanto não houve diferença estatística significativa (p>0,05) entre as mesmas. Este estudo revelou alta contaminação de praças públicas da cidade de Cuiabá por ovos de helmintos, incluindo os de importância em saúde pública, o que indica risco de transmissão dessas zoonoses a população.

The present work had the objective to evaluate the contamination of the public squares of Cuiabá, State of Mato Grosso, for faecal samples of dogs. Fifty five squares had been searched, of August the November of 2006. Of these, 14 beed situated in the center of city and 41 in diverse outlying areas of the city. The samples were collected per the morning, stored in processed plastic bags under refrigeration and in the Laboratory of Parasitic Illnesses of the Hospital Veterinarian of the UFMT, through the techniques of Willis-Mollay and Hoffmann, Pons and Janer, 1934. Of the 55 squares, 40 had faecal samples of dogs. To 121 samples had been all collected and in 45 eggs of helminths had been observed. Of these, 38 (84,4%) had presented eggs of Ancylostoma sp; 07 (15,5%) of Toxocara sp; 09 (20%) of Trichuris vulpis ones and 01 (2,2%) of Platynossomum sp and Cystoisospora sp. Twenty and two of the 121 joined samples had been in the squares central offices and 99 in the ones of outlying areas, however did not have difference significant statistics (p>0,05) between the same ones. This study it disclosed high contamination of public squares of the city of Cuiabá for eggs of helminths, including of importance in public health, what it indicates risk of transmission of these zoonosis the population.

Ocorrência de larva migrans na areia de áreas de lazer das escolas municipais de ensino infantil, Araçatuba, SP, Brasil / Presence of larva migrans in sand boxes of public elementary schools, Brazil

A areia das áreas de lazer de escolas podem constituir vias de transmissäo para várias zoonoses parasitárias, representando risco potencial para as crianças que brincam nesses locais. Foi avaliada a ocorrência de agentes de larva migrans em 28 escolas municipais de ensino infantil de Araçatuba, SP. Foram colhidas 535 amostras de areia das áreas de lazer dessas escolas nos meses de janeiro (veräo) e julho (inverno) de 1997 para estabelecimento da freqüência de isolamento de larvas e/ou ovos de Ancylostoma spp. e de ovos de Toxocara spp., pelos métodos de centrífugo-flutuaçäo e de Baermann, respectivamente. A presença de larvas de Ancylostoma spp. foi observada em, pelo menos, uma das amostras, em 35,7 por cento (10/28) das amostras da primeira colheita (veräo) e em 46,4 por cento (13/28) quando da segunda colheita (inverno). Ovos de Toxocara spp. näo foram encontrados e a presença de ovos de Ancylostoma spp. foi observada em 0,56 por cento (3/535) das amostras

Radiologic-pathologic findings in raccoon roundworm (Baylisascaris procyonis) encephalitis.

A 13-month-old boy developed eosinophilic meningoencephalitis, retinitis, and a protracted encephalopathy with severe residual deficits. The initial MR examination revealed diffuse periventricular white matter disease, and follow-up images showed atrophy. Brain biopsy, serology, and epidemiologic studies lead to the diagnosis of Baylisascaris procyonis infection, a parasitic disease contracted through exposure to soil contaminated by the eggs of a common raccoon intestinal roundworm. The pathologic, epidemiologic, and imaging features of this disease are herein reviewed.

Human toxocariasis and the visceral larva migrans syndrome: correlative immunopathology.

The surface of T. canis is now recognized as a dynamic structure which turns over quite rapidly and serves as a renewable source of large quantities of antigen(s). The major host responses to these antigens include a marked eosinophilia and hyperglobulinemia. Both of these responses are apparently ineffective at ridding the body of infective larvae. Both eosinphils and IgE antibodies are manifestations of the Th2 subset of T helper cells and the cytokines that they secrete. Further, there is reason to believe that the antigens released from T. canis larvae favor the induction of this cellular population. Finally, there is mounting evidence that the chronic production of parasite antigen and its continued stimulation of the host immune system with a concomitant production of eosinophils can lead to a permanent alteration of the normal organization of the cardiopulmonary system. In the absence of any well-documented drugs capable of killing infective larvae, it would seem that immunological intervention may offer the only way to minimize or neutralize this 'gift from man's best friend'. This chapter was not intended to be an exhaustive review of the literature pertaining to toxocariasis. Several other recent publications will hopefully fulfill the need for more detailed information on the biology of this organism and the clinical spectrum of the disease it produces [16, 138-140]. Finally, a MEDLARS search of the current medical literature should bring anyone up to speed in a very short time.

Visceral larva migrans: a seroepidemiological survey in five municipalities of Säo Paulo State, Brazil

Realzou-se inquérito soroepidemiológico, para detecçäo de anticorpos anti-Toxocara, em 2.025 soros de indivíduos residentes em cinco municípios do Estado de Säo Paulo (Säo Paulo, Campinas, Santos, Marília e Presidente Prudente), através de técnica imunoenzimática (ELISA) e emprego de antígenos obtidos a partir de larvas de 2§ - 3§ estádio de Toxocara canis. Após absroçäo com extratos de Ascaris lumbricoides, revelou-se a presença de anticorpos anti-Toxocara, em níveis significativos, em 3,60% dos soros examinados, com predominância de indivíduos com idade inferior a 15 anos (6,41%). Observou-se, ainda, tendência a ocorrerem índices mais elevados de infecçäo por larvas de Toxocara entre indivíduos residentes em municípios com maior densidade demográfica (Säo Paulo, Campinas e Santos), especialmente no grupo com menos de 15 anos de idade

Contacto domiciliar e profissional com caes como fatores de risco para infecçäo humana por larvas de Toxocara / Occupational and domiciliary contact with dogs as factor of risk to human infection with Toxocara larvae

Investigou-se o papel do contacto com cäes no domicílio e na atividade profissional como fatores de risco para transmissäo de larvas de Toxocara sp. a seres humanos, acarretando a síndrome de larva migrans visceral. Através de técnica imunoenzimática (E.L.I.S.A.) pesquisou-se a presença de anticorpos anti-Toxocara no soro de 79 mulheres adultas, residentes no município de Säo Paulo, que possuíam, ou possuíram nos dois últimos anos, cäes em seus domicílios e de 123 homens adultos, funcionários da Prefeitura Municipal de Säo Paulo, encarregados da captura de cäes vadios e de sua manutençäo em canis. Como controles utilizaram-se os soros de 205 mulheres adultas que näo possuíram, nos dois últimos anos, cäes em suas casas e de 139 homens adultos, cuja atividade profissional näo os obrigava a manter contacto com cäes. Os resultados indicaram que, nas condiçöes do presente trabalho, a posse de cäes no domicílio constitui fator de risco para transmissäo de larvas de Toxocara a seres humanos, ao contrário do verificado para o contacto profissional com cäes

Clinical, serologic, and epidemiologic characteristics of ocular toxocariasis.

The clinical, serologic, and epidemiologic characteristics of 17 cases of ocular toxocariasis (OT) were studied and compared with those of a control group of 15 cases of other ocular diseases whose differential diagnosis included retinoblastoma. The prevalence and mean titers of Toxocara antibody detected by enzyme-linked immunosorbent assay were greater (P less than 0.005) for patients with OT than for the control group, but not all clinically diagnosed OT cases had detectable antibody. The prevalence of pica was significantly greater in cases than in controls (P less than 0.05). Almost all case and control patients had a history of exposure to pet dogs and cats, but recent exposure to puppies (less than 3 months old) was significantly associated with Toxocara infection in this study group.

Diseases transmitted from pets to man: an evolving concern for veterinarians.

Pets are not a major source of human infections but they can transmit certain diseases to man. This transmission usually is complex, requiring close contact with pets or their excretions and frequently involves a breach of sound hygienic practice. In some instances, pathogens of animal origin are acquired inadvertently because infectivity can persist after evidence of gross contamination has gone. Veterinarians participate in controlling zoonotic diseases by encouraging rabies vaccination and hygienic treatment of pet feces and urine, by supporting community efforts toward responsible pet ownership and by advising on precautions for handling sick animals. It is recommended that veterinarians discourage the keeping of wild or exotic animals as pets and excess fondling of pets (particularly by children and pregnant women). Clients and kennel workers should be advised to use caution with animals that have aborted.

Visceral larva migrans and alveolar hydatid disease. Dangers real or imagined.

For both visceral larva migrans and alveolar hydatid diseases, it is the feces of companion animals that are the primary source of human infection. Clearly, whatever is done to reduce this form of environmental contamination and the prevalence of the parasites' infective stages will help to protect the health of the human population in the United States and Canada, particularly the children. Very important are appropriate anthelmintic treatment programs, especially for T. canis, and proper control of close associations between pets and people. Probably the known incidence of visceral larva migrans in humans and the range of its known pathogenicity will increase as better diagnostic methods become available. In addition, other animal helminths, for instance Toxocara cati and Toxascaris leonina, may become more substantially documented as causes of human visceral larva migrans. Until more is known of the geographical distribution and prevalence of Echinococcus multilocularis among animals in North America, it will be difficult to assess accurately the future significance of alveolar hydatid disease in the continent's human population. Another important advance would be the development of anthelmintics that are effective for somatic second stage larvae of T. canis, and others effective for adult or larval Echinococcus species. Meanwhile it is a most important responsibility of the veterinary profession to educate its clients thoroughly concerning these dangerous helminths.