Toxocara spp. egg contamination in the public parks of Northern Lima on recovery of body condition in adult dogs

© 2001 Universidad Nacional Mayor de San Marcos. All rights reserved. Toxocariasis is an important public health zoonosis, with ingestion of infective Toxocara spp. eggs producing both ocular and visceral larval migrant syndromes in human beings. In this study, Ievels of Toxocara spp. egg contamination were determined at 108 public parks in northem Lima. Soil and grass samples were collected using the double W method, during the months of July and August, 1999, when the average temperature was 18.5ºC with 90% relative humidity. The eggs were recovered by flotation in saturated CINa, and incubated for 30 days in a 2.5% K bicromate solution. Ofthe 108 parks sampled, 37 were found to be contaminated with Toxocara spp. eggs, accounting a prevalence of 34.3% ± 9.0. The highest prevalence, 64.5 ±16.8, was found in well maintained parks, followed by poorly and badly maintained parks with 27.6 and 18.8 ± l 1.1. The incidence in upper, upper middle, middle, lower middle and lower class neighborhood parks was 50.0; 66.7; 37.9; 25.8±15.4 and 17.9, respectively. Average contamination was 2.4 eggs per 100 g of sample. Viability of the Toxocara spp. eggs was tested by infecting 5 quail with 1500 recovered larval eggs each, with 5 quail studied as controls. The quail were culled at 24 hours, 5, 10, 15 and 20 days post-inoculation. Using the Baeimann method, larval migrants were recovered from the liver and, less frequently, in the lungs, heart, muscle and gizzard. No larval migrants were found in the control quail. It is clear that Toxocara spp. contamination in the public parks of northem Lima represents a signíficant threat to public health, and ít is ímperative that authoríties must try to control this problem at the earliest possíble date.