Toxocara canis en humanos, perros y suelos en ribera del Río de la Plata, provincia de Buenos Aires / Toxocara canis in humans, dogs and soil on the river side of Rio de la Plata, province of Buenos Aires / Toxocara canis em humanos, cães e solos nas margens do Rio da Prata, província de Buenos Aires

El objetivo de este trabajo fue describir la situación epidemiológica de toxocariosis en un hábitat ribereño. Se determinaron anticuerpos anti-toxocara por ELISA en sueros de 34 niños y 64 adultos, y se hallaron seroprevalencias de 32,3% y 45,3%, respectivamente. Esta fue alta en adultos y en niños de 2 a 3 años. Se realizaron 217 análisis coproparasitológicos de caninos y 23,04% fueron positivos para huevos de Toxocara canis. La distribución de caninos positivos por rango etario fue de 66% entre 1 y 6 meses; de 20,7% entre 6 y 12 meses; y de 10,3% en mayores de 12 meses. El porcentaje de animales parasitados por T. canis fue significativamente menor en relación a otros parásitos y disminuyó marcadamente con el aumento de la edad. Se analizaron 104 muestras de suelo y 1,92% de las mismas fueron positivas para huevos de T. canis. La escasa cantidad de huevos en suelos podría deberse a que los cachorros no se encontraban libres en los espacios públicos. En este barrio podría inferirse que el suelo no actuó como diseminador de esta parasitosis, sino que fueron de mayor relevancia factores como la tenencia de caninos menores de 1 año, el contacto estrecho con los mismos en ámbitos domiciliarios y las condiciones higiénico-sanitarias poco saludables.

The aim of this study was to describe the epidemiological situation of toxocariasis in a coastal habitat. Blood samples of 34 children and 64 adults were analyzed in order to determinate antibodies anti-toxocara by ELISA method. Prevalences of 32.3% and 45.3% were obtained respectively. A total of 217 coproparasitological canine analyses were performed, and 104 soil samples were analyzed. In humans, the seroprevalence of 32.4% in children and 45.3% in adults was found. In dogs, 50 samples were positive for T. canis eggs (23.04%). The distribution of canine positive for each age range yielded the following results: from 1 to 6 months, 66%; from 6 to 12 months, 20.7% and over 12 months, 10.3%. In soils, only 2 samples (1.92%) were positive for T. canis eggs. Seroloprevalence in humans was high, especially in adults and children aged 2 to 3 years. The percentage of parasitized animals by Toxocara was significantly lower in relation to other canine parasites and the percentage of dogs parasitized diminished significantly by increasing the age range. The low number of eggs found in soils could be due to the absence of puppies in public spaces. In this neighborhood, it can be inferred that the ground of public spaces did not act as a disseminator of this parasitosis, but that there were more relevant factors such as the possession of canines under 1 year of age, the close contact with them in residential areas, and unhealthy sanitary conditions.

O objetivo deste trabalho foi descrever a situação epidemiológica da toxocaríase em um habitat ripícola. Os anticorpos anti-toxocara foram determinados por ELISA em soros de 34 crianças e 64 adultos, com soroprevalência de 32,3% e 45,3%, respectivamente. Ela foi alta em adultos e em crianças de 2 a 3 anos de idade. Foram realizadas 217 análises coproparasitológicas caninas e 23,04% foram positivas para os ovos de Toxocara canis. A distribuição de caninos positivos por faixa etária foi de 66%, entre 1 e 6 meses, de 20,7%, entre 6 e 12 meses, e de 10,3% em maiores de 12 meses. A porcentagem de animais parasitados por T. canis foi significativamente menor em relação a outras parasitas e diminuiu marcadamente com o aumento da idade. Foram analisadas 104 amostras de solo e 1,92% delas foram positivas para ovos de T. canis. A escassa quantidade de ovos nos solos pode ser o resultado do fato de que os filhotes não estivessem livres nos espaços públicos. Poderia ser inferido que, nesse bairro, o solo não atuou como disseminador dessa parasitose, mas fatores como a posse de caninos menores de 1 ano de idade, um contato próximo com eles em ambientes domésticos e condições higiênico-sanitárias insalubres foram fatores de maior relevância.

Ectoparasites from some Myocastor coypus (Molina, 1782) populations (Coypus or Nutria) in Argentina / Ectoparasitas de algumas populações de Myocastor coypus (Molina, 1782) (Coypus ou Nutria) na Argentina

Abstract The occurrence of ectoparasites in wild nutria is poorly understood. Fifty-five livetrapped wild nutria (Myocastor coypus) from its indigenous region were examined for ectoparasites after capture from December 2013 to December 2014. The captures came from the Buenos Aires Province, by far the area of the country most densely populated by nutria, characterized as a temperate grassland, which are prime areas for sustained agriculture. Only one species of chewing lice (Pitrufquenia coypus, Marelli, 1932), one flea (Nosopsyllus fasciatus, Bosc, 1800) and one tick (Rhipicephalus sanguineus, Latreille, 1806) were collected. Fourteen percent of the animals were infested and P.coypus, an obligate parasite of the nutria, which was the most prevalent ectoparasite. N. fasciatus and R. sanguineus occurrence remains controversial as they may or may not be some accidental host species. To our knowledge, this is the first comprehensive and systematic survey of ectoparasites in wild nutria from the southern hemisphere, the indigenous region of this species.

Resumo A ocorrência de ectoparasitas em nutria selvagem é pouco compreendido. Cinquenta e cinco nutria selvagem capturadas (Myocastor coypus) de sua região indígena foram examinados para os ectoparasitas após até captura a partir de dezembro de 2013 a dezembro de 2014. As capturas ocorreram no estado de Buenos Aires, a área mais densamente povoada do país por nutria, caraterizada como uma pastagem temperada, que se tornou área principal para a agricultura sustentável. Uma espécie de piolhos de mastigação (Pitrufquenia coypus, Marelli, 1932), uma pulga (Nosopsyllus fasciatus, Bosc, 1800) e um carrapato (Rhipicephalus sanguineus, Latreille, 1806) foram recolhidos. Catorze por cento dos animais foram infestadas pelo P.coypus, um parasita obrigatório do nutria, sendo o ectoparasita mais prevalente. A ocorrência de N. fasciatus e R. sanguineus continua controversa, pois podem ou não ser algumas espécies hospedeiras acidentais. Para nosso conhecimento, este é o primeiro estudo abrangente e sistemático de ectoparasitas em nutria selvagem do hemisfério sul, a região indígena desta espécie.

Toxocariasis: seroprevalence in abandoned-institutionalized children and infants / Toxocariosis: seroprevalencia en infantes expósitos, abandonados e institucionalizados

Toxocariasis is an infection that has worldwide distribution. Toxocara canis is the most relevant agent due to its frequent occurrence in humans. Soil contamination with embryonated eggs is the primary source of T. canis. This study aimed to determine the seroprevalence of toxocariasis in 10-month to 3 year-old abandoned infants, considered to be at high risk because of their orphanhood status and early age. Blood samples were collected from 120 children institutionalized in an orphanage in the city of La Plata. In this study, we observed 38.33% of seropositive cases for T. canis by ELISA and 45% by Western blot techniques; significant differences among groups A (<1 year), B (1-2 years) and C (>2 years) were also found. In research group A, children presented a seropositivity rate of 23.91%, in group B of 42.85% and in group C of 56%, which indicates an increase in frequency as age advances, probably because of greater chances of contact with infective forms of the parasite since canines and soil are frequently infected with T. canis eggs. Abandoned children come from poor households, under highly unsanitary conditions resulting from inadequate or lack of water supply and sewer networks, and frequent promiscuity with canines, which promotes the occurrence of parasitic diseases. These children are highly vulnerable due to their orphanhood status and age.

La toxocariosis es una enfermedad presente en todo el mundo. Como causa primaria de infección se cita la contaminación de los suelos con huevos embrionados de Toxocara canis. Nuestro objetivo fue determinar la seroprevalencia de toxocariosis en niños expósitos (abandonados) de 10 meses hasta 3 años, los que se consideran de alto riesgo por su condición de orfandad y escasa edad. Las muestras de sangre fueron recolectadas de 120 niños institucionalizados en un orfelinato de la ciudad de La Plata. En este estudio, se observó un porcentaje de seropositivos para T. canis de 38,33 % por la técnica de ELISA y de 45 % por la técnica de Western blot, con diferencias significativas entre los grupos etarios estudiados (A: < 1 año, B: 1-2 años, C: > 2 años). Los niños del grupo A presentaron una frecuencia de seropositividad de 23,91 %; los del grupo B, de 42,85 % y en los niños del grupo C fue del 56 %. Esto indica un incremento de la frecuencia de presentación a medida que aumentó la edad, debido probablemente a las mayores posibilidades de contactar con estados infectantes del parásito, ya que los caninos y el suelo se hallan frecuentemente infectados por huevos de T. canis. Los niños abandonados provienen de hogares carenciados, donde a las malas condiciones de higiene resultantes de la ausencia de red de agua y cloacal se le agrega la frecuente promiscuidad con caninos, lo cual propicia la presencia de parasitosis. Sumado a la condición de desamparo, esto produce un estado de máxima vulnerabilidad.

Prevalence of a zoonotic parasite, dioctophyma renale (goeze, 1782), among male canines in a wild riverside area of la plata river, province of Buenos Aires, republic of Argentina

Dioctophymosis is an helminthiasis with an indirect life cycle caused by Dioctophyma renale. It mayaffect both humans and other mammals. The purpose of this study was to determine the prevalenceof the parasite in male canines of different ages, living in a wild riverside area of La Plata River with favourable characteristics for the development of eggs, intermediate or paratenic hosts and completionof the life cycle of D. renale. 171 animals were surveyed and samples were collected through urethral catheterization. The samples were processed by means of centrifugation at a relative centrifugal force of 700 g and microscopic observation of sediments. 42.1 percent of canines exhibitedpatent Dioctophymosis in their kidneys. Male canines between the ages of 2 and 5 showed the highest frequency of positive results. Several epidemiological risk factors are discussed that, whenassociated, might favour the high prevalence of this parasite in the area. The need for equipment for the indirect diagnosis of the disease in canines and other animals prone to infection is clearly demonstrated.

La Dioctofimosis es una helmintiasis de ciclo de vida indirecto causada por Dioctophyma renale. Puede afectar a los seres humanos y diferentes mamíferos. El propósito de este estudio fue determinar la prevalencia del parásito en caninos machos de diferentes edades, que viven en una zona rivereñaal Río de la Plata con características favorables para el desarrollo de los huevos, los huéspedes intermediarios o paraténicos y para el ciclo vida de D. renale. Fueron encuestados 171 animales, se recogieron muestras por medio de sondaje uretral. Las muestras se procesaron por centrifugación a una fuerza centrífuga relativa de 700 g y se observaron los sedimentos microscópicamente. El 42,1 por ciento de los caninos exhibió Dioctofimosis patente en sus riñones. Los caninos de sexo masculino con edades comprendidas entre 2 y 5 años presentaron la mayor frecuencia de resultados positivos. Se discuten varios factores de riesgo epidemiológico que asociados, podrían condicionar la elevada prevalencia de parasitosis en la zona. Se hace evidente la necesidad de equipos para el diagnósticoindirecto de la enfermedad en los caninos y otros animales propensos a infectarse.

Toxocara canis: migración larval y eosinofilia en el hospedador paraténico / Toxocara canis: larval migration and eosinophilia in the paratenic host

El objetivo de este trabajo fue analizar la relación entre el comportamiento migratorio larval de Toxocara canis y la eosinofilia en el hospedador paraténico. Utilizando al ratón como modelo experimental, debido a la similitud en la ruta migratoria y en la patogenia de este parásito en roedores y humanos. Se inocularon ratones Balb/c, por vía intragástrica con 250 (ñ 10) huevos larvados. Recuperación de larvas: se eligieron como órganos de referencia ojos y encéfalo. En encéfalo comenzaron a recuperarse larvas al 4º día y en ojo al día 21 post-inoculación. La asociación medida por el coeficiente de correlación, entre el tiempo de observación y larvas recuperadas en cada órgano fue: ojo derecho (OD) r=0,24; ojo izquierdo (OI) r=0,43; encéfalo (E) r=0,60. La recuperación de larvas inoculadas es significativamente mayor en encéfalo que en los globos oculares (chi cuad.: 185; p<0,00001). Los eosinófilos en el 80 por ciento de los ratones superó el 6 por ciento de la fórmula. La correlación entre eosinofilia y la recuperación de larvas en los órganos observados fue: 0,33 para el OD; 0,21 para OI y 0,44 para el encéfalo; estos valores de correlación se califican como bajos, sugiriendo la no asociación entre eosinofilia y la cantidad de larvas de T. canis que se alojen en ojos (toxocarosis ocular) o encéfalo (toxocarosis cerebroespinal)

Toxocarosis neurológica: descripción de un caso clínico / Neurologic toxocariasis: description of clinical case

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

Toxocariasis con afectación hepática / Toxocariasis with liver involvement

We are reporting 16 cases of toxocariasis found in a two year period. Mean age was 2 years and 9 months. Sex distribution was 1:1. Thirteen (81 per cent) children presented pica, 8 (50 per cent) had pets at home, 10 (62.5 per cent presented anemia and long standing fever, and all eosinophilic leukocytosis. Fundoscopy was normal in all. Toxocara antibodies (Through ELISA) were increased in all of them. High resolution ultrasonography revealed hypoechoic areas in the liver in 50 per cent of the cases. Therapeutic response was good, the clinical signs and symptoms disappearing at the end of treatment. The eosinophilic leukocytosis, ELISA serum positivity for toxocara and ultrasound findings persisted approximately for a year. Toxocariasis is a common parasitosis in our setting. It must be regarded as the first diagnosis when confronted with eosinophilic leukocytosis and abnormal liver findings by ultrasound.

Contaminación de suelos con huevos de toxocara sp. en plazas y parques públicos de la ciudad de La Plata, Buenos Aires, Argentina / Soil contamination by toxacara sp. eggs in squares and public places at La Plata, Buenos Aires, Argentina

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

Estudio de las infecciones por enteroparásitos en una comunidad periurbana de la provincia de Buenos Aires en Argentina / Study of enteroparasite infections in a periurban community at Buenos Aires, Argentina

A survey for intestinal parasites was performed on 38 individuals within the urban area of La Plata city (province of Buenos Aires, Argentina). This community is composed of brick-factory workers who also live in the factory premises. An analysis for intestinal parasites was done on fecal samples collected serially and by means of anal swabs and there after preserved in formol solution. At the same time, the ocurrence of the parasites under study as well as that of commensal organisms was investigated in water and soil samples within the factory environs. Information was also obtained from the members of this community as their age, sex, birthplace and recent travels, either abroad or to the interior of Argentina. The prevalence of the pathogens and commensal parasites was 89,5 percent. The frecuency of protozoans and helminths was: G. lamblia 26,3 percent; B. hominis 65,8 percent; A. lumbricoides 7,9 percent; H. nana 2,6 percent; uncinaria sp. 7,9 percent; S. stercoralis 2,6 percent and E. vermicularis 42,1 percent. None of these parasite or commensal organisms were present in the water samples investigated. Four out of 20 soil samples analyzed contained parasitic elements T. canis eggs (one); G. liamblia cysts (two) and A. lumbricoides eggs (one). These results indicated that most important factors causing such a high prevalence of coproparasites were the poor conditions of personal and community hygiene in combination with the frequent travels to the north and the northeast of the country, regions which are endemic parasitic areas. The implementation of programs on health education and communal sanitation would contribute in the control of this health problem