SummaryDioctophymosis is a parasitic disease occasioned by the so-called "giant kidney worm", Dioctophyme renale, a nematode with an indirect life cycle. This parasite's definitive host is the mink, Mustela vison, though numerous wild and domestic mammals as well 1 as man can serve as final hosts. The worms also can be in ectopic locations in the body.We surveyed 692 canines by ecography, urine sampling, surgery, necropsy, and clinical examination and diagnosed 244 cases of dioctophymosis (35.3%). Of the cases of dioctophymosis identified, 30.7% were obtained by ecography, 45.9% by urinalysis, and 17.6% by both those techniques -in addition to positive findings through surgery (2.5%), necropsy (2.5%), and the spontaneous elimination of the parasites (0.8%). Cases of dioctophymosis were observed in animals as young as 4 months of age up to 15 years.The frequency of D. renale diagnosis throughout the sampling period varied significantly. There was a statistically significant association between risk factors (swimming in the river, eating frogs, fish or eels, drinking ditch water) and the prevalence of infection. It was discussed the period missing after infection in canines.

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.

Dioctophymosis is an helminthiasis with an indirect life cycle caused by Dioctophyma renale. It may affect both humans and other mammals. The purpose of this study was to determine the prevalence of 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% of canines exhibited patent 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, when associated, 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.

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La dioctofimosis es una enfermedad parasitaria zoonótica, de distribución mundial, ciclo heteroxeno, producida por Dioctophyma renale; los adultos de estos nematodos se encuentran en tejidos, órganos y cavidades de una amplia variedad de mamíferos, los cánidos, con mayor prevalencia. Argentina presenta zonas endémicas, con alto potencial hídrico. La experiencia se realizó con los anélidos Aeolosoma hemprichi y Enchytraeidae, quienes cumplieron con criterios de inclusión prefijados para esta experiencia. Prueba Piloto. Se realizó en Mesocricetus auratus, inoculado con oligoqueto infectados in vitro, de familia Enchitraeidae, en su orina se hallaron huevos de D. renale infértiles en ecografías se observó, ausencia parcial de médula en riñón derecho, imagen vermiforme en cavidad abdominal y riñón. El riñón izquierdo mantuvo su forma y tamaño inalterado. Durante los controles se observó lesión cutánea neoformada, se supone que el verme abandono su ubicación por allí. Murió espontáneamente, en los preparados histopatológicos se observaron huevos y restos de nematodos mineralizados”, así como diversas lesiones coincidentes con las observadas en estudios histopatológicos de casos de dioctofimosis canina. Modelo experimental. Se utilizaron Rattus norvegicus Wistar fue n=10 para cada IME (Enchytraeidae y Aeolosoma hemprichi) y se mantuvo un animal como control. Se realizaron controles al igual que los del M. auratus, una rata (90 días IME, óbito, post anestesia - intra ecografía) en la cual se observó imágenes en hígado, compatible con D. renale. Se realizó necropsia, se enviaron: riñón derecho, riñón izquierdo e hígado y muestras granulomatosas, al servicio de patología, para cortes y coloración histopatológica: las lesiones glomerulares recuerdan aquellas observadas en casos de nefritis inmunomediadas. Se considera este comentario en el contexto de la reproducción experimental. Hígado: marcada congestión y ocasional presencia de amplia cavidad llena de sangre sin ningún tipo de respuesta tisular periférica. Riñón: ambos riñones presentan lesiones similares, observadas en casos de nefritis inmunomediadas. La presencia del hospedador intermediario, la alta prevalencia en caninos, los hábitos alimenticios y recreativos acuáticos de los pobladores, serían suficientes bases para plantear esta hipótesis. Hay que seguir estudiando la zona por posible transmisión a los humanos.