We report the first finding of Echinococcus vogeli in a paca, Cuniculus paca, in the tropical forest of Misiones, in the north of Argentina. The presence of the bush dog, Speothos venaticus, E. vogeli´s only natural definitive host, was also reported. The polycystic hydatids, 2 to 3 cm in diameter, were only found in the liver of an adult paca. The size range of the hooks and the relative proportion blade/handle did not show significant differences with respect to the ones reported for E. vogeli. The size of E. granulosus hooks, measured for comparison purposes, was significantly smaller (p < 0.0001). These results confirmed the presence of E. vogeli in Argentina. The probability of finding neotropical echinococcosis in humans reinforces the need to expand the search for E. vogeli in Argentina. Echinococcosis due to E. vogeli is very aggressive and may cause death in about a third of the human population affected.

Se presenta el primer hallazgo de Echinococcus vogeli en una paca (Cuniculus paca) del bosque tropical de Misiones, norte argentino. Se confirmó también la presencia de su único hospedador natural definitivo conocido, el perro silvestre (Speothos venaticus). Las hidátides poliquísticas, de 2-3 cm de diámetro, se encontraron solo en el hígado de una paca adulta. El rango promedio del largo de los ganchos y la proporción relativa hoja/ mango no mostraron diferencias significativas con respecto a lo ya afirmado para E. voge li. Los ganchos de E. granulosus, medidos como comparación, fueron significativamente más pequeños (p < 0,0001). Estos resultados confirmaron la presencia de E. vogeli en Argentina. La probabilidad de encontrar equinococosis neotropical en el hombre refuerza la importancia de determinar la distribución de E. vogeli en la Argentina. La equinococosis causada por E. vogeli es muy agresiva y puede producir mortalidad hasta en un tercio de la población humana afectada.

Trypanosoma cruzi and Trypanosoma rangeli-like trypanosomes have been found in a variety of neotropical bat species. In this study, bats (Artibeus lituratus, Carollia perspicillata, Desmodus rotundus, Glossophaga soricina, Molossus molossus, Phyllostomus hastatus) were maintained under controlled conditions, and experiments were conducted to determine how they might become infected naturally with trypanosomes. All bats were first screened for existing infections by hemoculture and the examination of blood smears, and only apparently uninfected animals were then used in the experiments. Proof was obtained that the triatomine bug Rhodnius prolixus would readily feed upon some of the bats, and two species became infected after being bitten by bugs infected with T. rangeli. Some bats also became infected by ingesting R. prolixus carrying T. cruzi, or following subcutaneous or intragastic inoculation with fecal suspensions of R. prolixus containing T. cruzi. P. hastatus became infected after ingesting mice carrying T. cruzi. All of the bats studied inhabit roosts that may be occupied by triatomine bugs and, with the exception of D. rotundus, all also feed to at least some extent upon insects. These findings provide further evidence of how bats may play significant roles in the epidemiology of T. cruzi and T. rangeli in the New World tropics.