The prospective role of the land snail Rumina decollata as a potential paratenic host of Toxocara cati for domestic cats was studied. R. decollata specimens and cats' feces were collected from the open spaces of a Buenos Aires city hospital. Cats' feces were analyzed and snails were digested to identify T. cati stages, by morphological and molecular analyses. T. cati larval eggs were recovered from 23.5% (4/17) of the sampled feces. Twenty percent of snail pools (5/25) were confirmed to be positive for Toxocara spp. third larval stage (L3) by PCR. The mean value of total larvae recovered per gram of snail in all positive pools was 5.1, with a maximum 33 L3/pool. This is the first report of T. cati infective larvae in R. decollata domestic snail as a paratenic host, since the relationship between infection in snails and in cats' feces could be demonstrated in a common environment.

Se estudió el rol prospectivo de Rumina decollata como potencial hospedador paraténico de Toxocara cati para los gatos domésticos. Se recolectaron caracoles R. decollata y heces de gatos de un hospital de la Ciudad Autónoma de Buenos Aires. Se procesaron las heces y los caracoles fueron digeridos para identificar estadios de T. cati por análisis morfológico y molecular. El 23,5% (4/17) de las muestras de heces resultaron positivas a huevos larvados de T. cati. El 20% (5/25) de los pooles de caracoles fue positivo a larvas de tercer estadío (L3) de Toxocara spp. por PCR. El promedio de larvas totales recuperadas por gramo de caracol en todos los pooles positivos fue de 5.1, con un máximo de 33 L3/pool. Se trata del primer reporte de R. decollata como hospedador paraténico de T. cati, puesto que ha sido demostrada la infección en caracoles y gatos en un ambiente común.

The objective of this study was to analize the migratory behaviour of larvae of Toxocara canis related to eosinophilia in paratenic hosts. Mice were used as experimental models. In rodents and humans the migratory route and the pathogenesis of the parasite are similar. Balb/c mice were inoculated intragastrically with 250 (± 10) embryonated eggs. Larvae recovery: eyes and encephalon were chosen as reference organs. In the encephalon and the eye, larval recovery began in the forth and twelfth day post-inoculation respectively. The association measured by the correlation coefficient between time of observation and recovered larvae in each organ was: right eye (RE) r= 0.24; left eye (LE) r= 0.43; encephalon (E) r= 0.60. The recovery of inoculated larvae is significantly higher in the encephalon than in the eyeballs (Chi square: 185; p < 0.00001), in 80 % of mice eosinophils exceeded 6% of the formula. The correlation between eosinophilia and larval recovery in the organs observed was: 0.33 for the right eye (RE); 0.21 for the left eye (LE) and 0.44 for the encephalon; these correlation values are considered low, suggesting no association between eosinophilia and the quantity of T. canis larvae lodged in the eyes (ocular toxocarosis) or in the encephalon (cerebrospinal toxocarosis).