SUMMARYMost studies from Argentina have focused on toxocariasis as an environmental problem of big cities, and there are no available data about children infection from small or middle-sized cities. In order to assess the prevalence of anti-Toxocara antibodies in infantile population, 206 children from Resistencia, of both sexes, aged 1-14 years old were studied by Elisa testing with E/S T. canis L 2 antigens. Hematological parameters and immunoglobulin levels were determined; five days' stool samples were studied and epidemiological data were obtained by means of a questionnaire to parents. Results showed that 73% of the children had one or more dogs living at home, 57% reported geophagia and 37.9% were positive for Toxocara serology, but there was no significant difference in prevalence neither for boys and girls, nor concerning age. An increased risk of infection was observed in age groups 5-6 and 7-8 for boys, and in age groups 3-4 and 5-6 for girls. KEYWORDS: Toxocariasis; Toxocara canis; Visceral larva migrans; SeroprevalenceHuman toxocariasis is probably one of the most widely spread zoonotic nematode infection. Toxocara eggs acquired by hand-to-mouth contact hatch in the stomach and the larvae migrate through human soft tissues leading to visceral larva migrans (VLM) or ocular larva migrans (OLM) 8 . As the parasite does not develop in man until adulthood, the examination of fecal specimens is not helpful; thus the diagnosis of toxocariasis as well as the assessment of its importance in population, can only be achieved through serological tests. In developed countries, VLM has been referred to as the second most common type of helminthic infection; in developing countries, although other helminthiasis are highly prevalent, human toxocariasis is likely to be also very frequent 14 .Most of the studies from Argentina have focused on toxocariasis as an environmental problem of big cities 13,15 ; there are few reports about human infection, particularly in children, and there are no available data from small or middle-sized cities where urban contamination presents different characteristics from those in big ones, due to the particular relationship that its inhabitants establish with the surrounding environment 5 . All these circumstances have led us to assess the prevalence of anti-Toxocara antibodies in a middle-sized subtropical city's infantile population in Argentina.A survey was carried out in Resistencia, a city located in the northeast of Argentina (27º10' S, 58º58' W, and at 53 m above sea level), and characterized by a subtropical climate with hot and humid summers and moderately mild and dry winters (average annual temperature of 20.5 º C; mean annual rainfall of 1350 mm). The city has more than 350,000 inhabitants and people live predominantly in individual houses with front gardens, backyards, and wide sidewalks with a narrow paved area, the rest being bare ground or partially covered by grass. Only 20% of the urban area has paved streets, about 70% of the families own dogs and stray dogs are qui...

With the aim of studying the contamination of soils with eggs of Toxocara spp. in an arid area in the central-western region of Argentina, 76 soil samples were collected from 18 towns belonging to six provinces of central-western Argentina. They were processed by the centrifugal flotation method. No eggs of Toxocara spp. were found. It can be concluded that the negative results are directly related to the characteristics of the environment and climate present in the studied area. The finding of eggs in soils depends on several factors: the presence of canine or feline feces, the hygienic behavior of pet owners, the presence of stray animals without veterinary supervision, the weather and environmental conditions, and laboratory techniques used; and all these circumstances must be considered when comparing the results found in different geographical regions. In order to accurately define the importance of public spaces in the transmission of infection to humans, it is important to consider the role of backyards or green spaces around housing in small towns, where the population is not used to walking pets in public spaces, and in such cases a significant fraction of the population may acquire the infection within households.

Toxocara canis INFECTION IN ADULT HEALTHY POPULATION FROM INTRODUCCIÓNLa característica casi genética del hombre de vivir rodeado de animales domésticos, ha facilitado que la toxocarosis sea una saprozoonosis helmíntica ampliamente difundida en todo el mundo 1 . La infección humana por Toxocara canis se produce por la ingestión de huevos embrionados a partir del contacto con suelos infectados, por geofagia, por manos mal lavadas, por onicofagia y en menor proporción por el consumo de vegetales contaminados 3 . También ha sido descripta la infección a partir de carnes poco cocinadas procedentes de huéspedes paraténicos 2 y recientemente se demostró que el contacto directo con el pelaje de perros infectados podría constituir una vía válida de adquisición de la infección 4 . La transmisión de larvas infectantes por otras vías como la hemática o la

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The aim of this work was to evaluate a dot-enzyme-linked immunosorbent assay (dot-ELISA) using excretory-secretory antigens from the larval stages of Toxocara canis for the diagnosis of toxocariasis. A secondary aim was to establish the optimal conditions for its use in an area with a high prevalence of human T. canis infection. The dot-ELISA test was standardised using different concentrations of the antigen fixed on nitrocellulose paper strips and increasing dilutions of the serum and conjugate. Both the dot-ELISA and standard ELISA methods were tested in parallel with the same batch of sera from controls and from individuals living in the problem area. The best results were obtained with 1.33 µg/mL of antigen, dilutions of 1/80 for the samples and controls and a dilution of 1/5,000 for the anti-human IgG-peroxidase conjugate. All steps of the procedure were performed at room temperature. The coincidence between ELISA and dot-ELISA was 85% and the kappa index was 0.72. The dot-ELISA test described here is rapid, easy to perform and does not require expensive equipment. Thus, this test is suitable for the serological diagnosis of human T. canis infection in field surveys and in the primary health care centres of endemic regions