Association between contamination of public squares and seropositivity for Toxocara spp. in children

Abstract

A concomitant study was carried out, of the association of positive serology for Toxocara spp. in 90 children who played in public squares used for leisure, with the frequency with which each child used these areas, and the presence of eggs of Toxocara spp. in the sand or grass in these locations. The sand and grass of their peridomiciles and school playgrounds, as well as the feces of their dogs were also analyzed for Toxocara. Serum samples were tested for IgG antibodies to Toxocara canis excreted-secreted larval antigens by ELISA, and blood samples for eosinophilia. The water-sedimentation technique was used to evaluate the presence of parasite eggs in the sand and grass turfs, and in feces of the dogs that also frequented these locations. 16/90 (17.8%) of the children were seropositive for Toxocara spp. There was a positive association between seropositivity in children who played in the public squares six or seven times a week, with a parasite load above 1.1 eggs/g of sand, as well as with contamination of the peridomicile, even at less than 1.0 egg/g of sand. Eosinophilia, the habit of geophagy, age from one to four years, and the presence of parasitized pet dogs were also positively correlated with seropositivity in the children. Eggs were found in 15/15 (100%) of the public squares, 17/90 (18.9%) of the peridomiciles, 3/13 (23.1%) of the schools, and 12/41 (29.3%) of the dogs living in the peridomiciles investigated.

A Systematic Review of Toxocariasis: A Neglected But High-Prevalence Disease in Brazil

“…10,27,[30][31][32]36,40 In all of these studies, a higher proportion of patients with asthma was found among those infected with Toxocara, which lends this infection greater relevance in terms of public health.…”

Toxocariasis and Public Health: An Epidemiological Review

“…Studies have concentrated on assessing egg contamination of playgrounds, parks, sandpits, and backyards/gardens and have shown contamination to be prevalent [47]. Although such areas seem to provide opportunities for infection, the role of different domestic and wild defi nitive hosts in the contamination of these areas is unclear (McPherson, 2013).…”

Prevalência De Toxocaríase E Fatores Associados Em Crianças De Uma Escola Pública Em Belo Horizonte, Minas Gerais, Brasil

“…O simples hábito de lavar as mãos diminui as chances de se contaminar e foi estatisticamente associado ao decréscimo da prevalência (34). A correta vermifugação de cães e gatos, tanto filhotes quanto animais adultos é de extrema importân-cia, pois a presença de animais não parasitados contribui significativamente para a soronegatividade em crianças (14). A vermifugação de filhotes deve ocorrer com dois, quatro, seis e oito semanas de idade, e depois mensalmente até os seis meses; sendo que em gatos ela pode começar com três semanas (66).…”

“…Estudos demonstraram altas taxas de contaminação em ambientes públicos, como praças e parques, com ovos provenientes das fezes de cães parasitados (13)(14)(15)(16)(17), o que faz com que essa doença seja de grande importân-cia para a saúde pública.…”