Environmental contamination with Toxocara spp. eggs in public parks and playground sandpits of Greater Lisbon, Portugal

Abstract

Toxocarosis is a zoonotic parasitic disease transmitted from companion animals to humans. Environmental contamination with Toxocara eggs is considered to be the main source of human infections. In Portugal, knowledge regarding the current situation, including density, distribution and environmental contamination by Toxocara spp., is largely unknown. The present study investigated environmental contamination with Toxocara spp. eggs, in soil and faecal samples collected from public parks and playground sandpits in Greater Lisbon, Portugal. A total of 151 soil samples and 135 canine faecal samples were collected from 7 public sandpits and 12 public parks, over a 4 month-period. Soil samples were tested by a modified centrifugation and sedimentation/flotation technique and faecal samples were tested by an adaptation of the Cornell-Wisconsin method. Molecular analysis and sequencing were performed to discriminate Toxocara species in the soil. Overall, 85.7% of the sandpits (6/7) and 50.0% of the parks (6/12) were contaminated with Toxocara spp. eggs. The molecular analysis of soil samples showed that, 85.5% of the sandpits and 34.4% of the parks were contaminated with Toxocara cati eggs. Faecal analysis showed that 12.5% of the sandpits and 3.9% of the parks contained Toxocara canis eggs. In total, 53.0% of soil and 5.9% of faecal samples were positive for Toxocara spp. Additionally, 56.0% of the eggs recovered from the samples were embryonated after 60 days of incubation, therefore considered viable and infective. The average density was 4.2 eggs per hundred grams of soil. Public parks and playground sandpits in the Lisbon area were found to be heavily contaminated with T. cati eggs, representing a serious menace to public health as the studied areas represent common places where people of all ages, particularly children, recreate. This study sounds an alarm bell regarding the necessity to undertake effective measures such as reduction of stray animals, active faecal collection by pet owners, awareness campaigns and control strategies to decrease the high risk to both animal and human health.

Toxocariasis and Public Health: An Epidemiological Review

“…However, the following soil treatment procedures worthy of note include rigorous faecal removal practices, regularly replacing sand or sterilizing it, and eliminating sandpits or sandcastles altogether in public areas [82].…”

“…In order to increase awareness of the potential zoonotic hazards, veterinary practitioners, general practitioners and public health agencies should provide suffi cient information and advice for minimizing the risk of infection. Health education and discouraging geophagia in children are fundamental [82].…”

Presence of zoonotichelminths in cats (Feliscatus) of condominiums in City of Mexico with special concern to Toxocara cati infection

“…Its epidemiological clinical importance lies in the fact that its main transmission mechanism involves the profuse contamination of the soil with fecal matter that evacuates two of the pets that closely coexist with the human being, the cat and the dog. Toxocariasis is caused by the intestinal helminths of the dog and the cat Toxocaracanis and Toxocaracati, respectively [1][2][3]. Both animals are infected by different mechanisms such as: ingestion of embryonated eggs, migration through the placenta of larvae that have remained in the tissues of the mother, ingestion of larvae present in breast milk and the consumption of paratenic hosts with the infective larvae [4].…”

Legal aspects associated with the lack of possibilities of preventing the spread of toxocarosis and toxoplasmosis in Poland

“…Source of zoonosis are the sick and infected animals that have direct contact with humans as well as animals which constitute a source of food for people [1][2][3][4][5][6][7][8][9][10][11][12]. The development of civilization does not always limit incidents of contagion with a disease, which could not be eliminated even in developed countries [14,[13][14][15][16][17][18][19][20].…”