Toxocariasis: serological diagnosis by enzyme immunoassay.

Abstract

SUMMARY An enzyme-immunoassay was developed to measure the concentration of serum antibody specific for the secretary antigens released by migrating toxocaral larvae. This technique was evaluated by testing sera from healthy UK adults, and from patients with and without toxocariasis. In 922 healthy adults, 2-6 % were found to have elevated specific antibody levels. Elevated values were observed twice as frequently in males as in females but showed no significant regression with age between 20 and 65 years. Of 62 patients with non-toxocaral helminthic infections, all had antitoxocaral antibody levels within the range of values observed in healthy controls and had a mean level which was not significantly elevated. All of 13 patients with clinical toxocariasis had enzymelinked immunosorbent assay (ELISA) antibody levels above the 100th percentiles of both the healthy population and the helminth-infected group and had a significantly high mean value (P < 0.001) more than 12 times that of the healthy or infected controls.The high degree of sensitivity and specificity of the toxocariasis enzyme-immunoassay indicates that this new test should be useful in reference immunodiagnostic applications and in large-scale seroepidemiological surveys.

Frequency and risk factors for toxocariasis in children from a pediatric outpatient center in southeastern Brazil

“…antigens and Ascaris sp. antibodies 6,14,15 . A goat antihuman IgG (Gamma-Chain) specific peroxidase conjugate was used.…”

Human toxocariasis: contribution by Brazilian researchers

“…The introduction of Immunoenzymatic assay (ELISA), based on the use of antigen extracted from larval culture of T. canis (antigen TES), resulted in a test with good specificity and sensitivity 21,40,51 . However, the evaluation of the true sensitivity and specificity of serological tests for toxocariasis in human populations is not possible due to lack of parasitological methods to diagnose the disease in a definitive form.…”

Toxocariasis in children attending a Public Health Service Pneumology Unit in Paraná State, Brazil

“…Anti-Toxocara spp. IgG antibodies were detected by means of an ELISA test using TES antigens, which were obtained according to the method of DE SAVIGNY et al (1979) 6 , modified by ELEFANT et al (2001) 7 . All sera were previously absorbed with Ascaris suum antigens 7 .…”

“…The method of choice for both immunodiagnostic and epidemiological studies is the enzyme-linked immunosorbent assay (ELISA) test using the excretory-secretory antigens of infective larvae of T. canis (TES), which possess high sensitivity and specificity 6,20,25 . Many studies concerning the seroprevalence of toxocariasis in children have been conducted in Brazil reporting 12.1-60.0% in the northeast 9,22,26 , 3.0-35.5% in the midwest 9,22 , 21.5-52.0% in the north 9,22 and 2.8-54.8% in the southeast 9,22,25 .…”