Prevalencia de leptospiras en Rattus rattus y Rattus norvegicus en el Gran Buenos Aires, Argentina

Leptospires prevalence in Rattus rattus and Rattus norvegicus in Buenos Aires Prov- ince, Argentina: Positive isolation of leptospires prevalence is described in naturally infected rats in the ivillai La Cava, San Isidro, Buenos Aires Province. Monthly captures, each lasting three days, were performed from December 1995 until November 1996. Species, sex and weight of rats captured were determined. The prevalence rates (leptospiras were isolated from kidneys) were 45.8% in Rattus norvegicus and 18.1% in Rattus rattus. The isolations corresponded to viru- lent strains of Leptospira interrogans serogroup Icterohaemorrhagiae. In Rattus norvegicus there was not significant difference among prevalence rates according to sex or weight. The high and persistent prevalence is a risk for human and animals living in the studied area.