Study of the reproductive capacity of Trichinella spiralis recovered from experimentally infected mice under-dosed with albendazole or mebendazole.

The reproductive capacity of Trichinella spiralis recovered from experimentally infected mice under-dosed with albendazole (ALB) or mebendazole (MEB) was studied. Different groups of male C57/BL mice were infected with 10 +/- 0.5 muscular larvae (ML) per gram of body weight and treated with a single dose by oral (20 mg/kg) of ALB, MEB or praziquantel (PZQ) given at 5th day post infection (DPI), during the intestinal phase of infection. In other group of mice, treatment with the same drugs and dosage was for seven days, starting at day 45 PI through the stage of encapsulating larvae (parenteral phase of infection). A reduction of 72.9 to 89.9% in the parasitic load was observed in ALB or MEB treated groups but not in mice untreated or administered with PZQ. The recovered larvae were used to infect naïve mice and, after 45 DPI, a similar Reproductive Capacity Index (RCI) was observed between the different groups (P=0.323, one-way ANOVA), either from mice infected with larvae recovered from the intestinal treatments (RCI-ALB = 51.6 +/- 12.1 and RCI-MEB = 49.2 +/- 14.) or from the parenteral ones (RCI-ALB = 52.2 +/- 14.0 and RCI-MEB = 51.9 +/- 11.8). The RCI of non-treated ML was 59.5 +/- 7.7 and 57.9 +/- 15.9 for PZQ. This information is significant for practical strategies when under-dosage is dispensed.