Contamination of eastern Lima's public parks with Toxocara spp. eggs

© 2000 Universidad Nacional Mayor de San Marcos. All rights reserved. Toxocariasis has been recognized as an important zoonosis because the intake of infective Toxocara spp. eggs produces ocular migrant larva syndrome in humans, especially children. The objective of the present study was to evaluate the contamination of eastern Lirna's public parks with Toxocara spp. eggs. Turf samples were collected from 151 ofthe 325 public parks using double W method during February and March 1999. Mean environmental temperature was 24.2 C with 81.5% relative humidity. Eggs were collected by flotation in supersaturated NaCl solution and subsequently incubated in 2.5% potassium dichromate solution for 30 days. Toxocara spp. egg contamination was found in 62 or 41.1 %± 7 .8% of the 151 parks studied. Classification of the parks according to the socio-economic status of their neighborhoods revealed contamination frequencies of 87 .5, 46.2, 50.0, 34. 7 and 37.1 % for upper, upper-middle, middle, lowermiddle and lower class status respectively. Contamination rates of 92.3%, 44.7% and 7.7% were found for parks with good grass cover, moderate grass cover (around 50% covered with grass) and poor to non-existent grass cover, with an average of 3.04 eggs per l 00 g of sample. To test viability, four 3 three week old quails were infected with 1500 eggs and 4 controls were studied. Necropsies were perfonned at 24 hours, 5, 1 O and 15 days post-inoculation, and visceral larval migrants were collected using the Baennan technique from the liver, as well as heart, muscle, gizzard lungs and eyes. Clearly lhe Toxocara spp. contamination levels in eastern Lima's public parks representa significant threat to public health, and it is imperative that local authorities implement appropriate regulations to eliminate this problem.