Toxocariasis, Intestinal Parasitoses and Eosinophilia in Schoolchildren from Argentina.

The purpose was to analyze the relationship between toxocariasis, intestinal parasitosis, eosinophilia, pet ownership and signs and symptoms present in 370 schoolchildren (3-12 years old) of Argentina. The positive serology for toxocariasis was 19.5%, associated with eosinophilia and possession of cats as pets. The stool testing revealed 70.0% of parasitized children. Its frequency was 44.9% helminthes and 53.5% protozoan resulting single significant presence of protozoa in children aged 10-12 years. The species were: Blastocystis hominis (45.7%), Enterobius vermicularis (43.2%), Giardia intestinalis (16.2%), Hymenolepis nana (2.4%), Ascaris lumbridoides (1.6%) and Trichuris trichiura (0.3%). The survey showed 13.0% of children with sporadic abdominal pain and 13.5% with pruritus ani. The results indicate relationship between positive serology and eosinophilia compatible with a clinical aspect of covert toxocariasis self-limiting, associated with cats ownership; in school children from our region who also have high frequency of intestinal parasitoses.

Effect of Paecilomyces lilacinus on the viability of oncospheres of Taenia hydatigena.

Paecilomyces lilacinus (Thom) Samson is a saprophytic hyphomycete from the soil with biological activity on helminth eggs. We evaluated the influence in vitro of P. lilacinus on the viability of the oncospheres from Taenia hydatigena, a parasite cestode of dogs and sheep. The eggs were exposed to the fungus strain in sterile distilled water and observed by light microscopy at days 4, 7 and 14 post-inoculation, and the viability was evaluated. The viability found in the exposed P. lilacinus oncospheres was significantly different in all observations. P. lilacinus exercised a negative biological activity on T. hydatigena eggs in vitro.

Biological interaction between soil fungi and Toxocara canis eggs.

Fungi from the soil of public areas in La Plata, Argentina were isolated and evaluated for their biological interaction with Toxocara canis eggs in vitro. We isolated and identified two fungal species: Fusarium pallidoroseum and Mucor hiemalis. Each species was co-cultured with T. canis eggs in sterile distilled water. The samples were observed by light and scanning electron microscopy (SEM) at days 4, 7 and 14 post-inoculation. Under the conditions of our experiments, F. pallidoroseum exhibited a high ovicidal activity on T. canis eggs, whereas M. hiemalis exhibited no such effects.

Biological activity of Paecilomyces genus against Toxocara canis eggs.

Saprophytic soil fungi can exert ovicidal and ovistatic effects on helminths with differing degrees of efficiency. The representatives of such fungi from temperate regions, Paecilomyces lilacinus (Thom) Samson and P. marquandii (Masse) Hughes, exhibit recognized ovicidal activity on some nematodes. We evaluated the action in vitro of P. lilacinus and P. marquandii on the zoonotic canine roundworm eggs of Toxocara canis. Eggs exposed and unexposed to fungal samples were observed by both light and scanning electron microscopy on days 4, 7 and 14 post-inoculation. Ovicidal activity of P. lilacinus on T. canis eggs was considered to be high and that of P. marquandii to be intermediate.

Anthelmintic efficacy of tinidazole against the progression of Toxocara canis larvae to the brain in mice.

The anthelmintic effect of tinidazole (100 mg/kg per day for 3 successive days) was tested in male Swiss CF-1 mice infected with second-stage Toxocara canis larvae at challenge doses of 250, 500, 1000, and 1500 embryonated eggs per mouse. The drug was given orally on days 3-5 postinfection (p.i.) to one-half of the animals, and all mice were killed on day 40 p.i. The number of larvae recovered from each mouse's brain and skeletal muscle was then scored in both groups. Tinidazole yielded a highly significant reduction in the total recovery of larvae from the test animals' brains at the second and third inoculum levels but no statistically significant reduction at the highest larval dose as compared with the values obtained in the untreated control animals.

[Asthma and covert toxocariasis]. / Asma y toxocarosis encubierta.

The relationship between asthma and covert toxocariasis was studied in 38 patients with asthma and 44 control individuals (without asthma). Inclusion/exclusion criteria were determined. An ELISA test based on the detection of Anti-Toxocara canis (E/S antigen) serum immunoglobulin G (Ig G) and E (Ig E) was determined in both groups. Ordinary allergens and E/S antigen of T. canis injections were used to evaluate cutaneous reactivity. The seroprevalence in patients with asthma was 68.42%, and in the control individuals was 13.63%. This difference was significant. The percentage of asthmatic patients with two antitoxocara antibodies was 26.31% and 4.54% in control individuals. All asthmatic patients with antitoxocara IgE had cutaneous reactivity to Ag E/S. We conclude that the asthmatic patients with IgE and IgG antitoxocara suffer a covert toxocarosis.

Asma y toxocarosis encubierta. / [Asthma and covert toxocariasis]

The relationship between asthma and covert toxocariasis was studied in 38 patients with asthma and 44 control individuals (without asthma). Inclusion/exclusion criteria were determined. An ELISA test based on the detection of Anti-Toxocara canis (E/S antigen) serum immunoglobulin G (Ig G) and E (Ig E) was determined in both groups. Ordinary allergens and E/S antigen of T. canis injections were used to evaluate cutaneous reactivity. The seroprevalence in patients with asthma was 68.42

, and in the control individuals was 13.63

. This difference was significant. The percentage of asthmatic patients with two antitoxocara antibodies was 26.31

and 4.54

in control individuals. All asthmatic patients with antitoxocara IgE had cutaneous reactivity to Ag E/S. We conclude that the asthmatic patients with IgE and IgG antitoxocara suffer a covert toxocarosis.