Toxoplasma (Toxo) IgG EIA

For the qualitative, semi-quantitative, or quantitative detection of human IgG antibodies to Toxoplasma gondii in human serum by enzyme immunoassay, as an aid in the determination of infection with Toxoplasma. When used as a qualitative test, Toxoplasma IgG EIA aids in the assessment of the patient's immunological response to Toxoplasma. 

About Toxoplasmosis

Serologic studies indicate that infection with Toxoplasma gondii, an intracellular parasite and the causative agent of toxoplasmosis, is fairly widespread in the population worldwide. For example, it has been estimated that 30% of the population in the United States exhibits serological evidence of exposure to Toxoplasma gondii.¹ The organism can be transmitted during organ transplantation ², by blood or leukocyte transfusion ³, contact with contaminated cat feces ⁴, or by ingestion of raw or undercooked meat from infected animals.⁵

In adults the infection is usually asymptomatic, although symptomatic as well as fatal cases do occur. Symptoms range from swollen lymph nodes to those resembling infectious mononucleosis.¹ In children, the disease may affect the central nervous system and the viscera. Congenital infection also occurs, and toxoplasmosis is a significant cause of mortality and congenital malformation. ^6-9

Specific IgG antibody titers directed against Toxoplasma gondii prior to pregnancy are correlated with immunity to infection.³ Inasmuch as infection may occur in utero if serologically negative women become infected during pregnancy, it is advisable for pregnant women to be tested for Toxoplasma specific antibodies early during their pregnancy, and serologically negative women should be monitored for Toxoplasma IgG antibody during their pregnancy and at delivery. Serologically positive results should be followed-up by testing for Toxoplasma specific IgM in the newborn. Because less than one percent of newborns are born with maternally transferred IgM, the presence of Toxoplasma specific IgM antibodies is an indication of toxoplasmosis. ¹⁰

The results of serologic tests are of value as presumptive evidence of toxoplasmosis. The Toxoplasma IgG EIA test in intended for the detection of IgG antibodies to Toxoplasma. Test results are obtained after one and one-half hours incubation time. They are objective and normalized as Index values, or as International Units (IU/mL), which are traceable to the WHO Anti-Toxoplasma Serum, 3rd International Standard Preparation, 1994.

Diluted samples are incubated in antigen-coated wells. Toxoplasma antibodies (if present) are immobilized in the wells. Residual sample is eliminated by washing and draining, and conjugate (enzyme labeled antibodies to human IgG) is added and incubated. If IgG antibodies to Toxoplasma are present, the conjugate will be immobilized in the wells. Residual conjugate is eliminated by washing and draining, and the substrate is added and incubated. In the presence of the enzyme, the substrate is converted to a yellow end product which is read photometrically. Test performed by VRL Eurofins,  6933 S. Revere Parkway, Centennial, CO 80112. This test has not been cleared or approved for diagnostic use by the U.S. Food and Drug Administration. See package insert for more information.