Toxoplasma gondii Ab,IgG

Laboratory assay overview

CMV: Routine screening of pregnant people for CMV is not recommended by current guidelines. Maternal CMV IgM antibody has limited clinical utility in differentiating primary from recurrent infection. An IgG-positive, IgM-negative result typically indicates past infection; however, IgG avidity testing, to determine the time since primary infection, should be considered if clinically warranted. An IgG-positive, IgM-positive result suggests recent primary infection and IgG avidity testing is recommended to determine the time since primary infection. An IgG-negative, IgM-positive result suggests very recent infection and the patient should be followed to document seroconversion. An IgG-negative, IgM-negative result indicates susceptibility to infection. Parvovirus B19: Routine screening of pregnant people for parvovirus B19 is not recommended by current guidelines. Testing should be performed for those patients with symptoms consistent with parvovirus B19 infection or for those with exposure to suspected or confirmed acute infections. Women who are negative for both IgG and IgM are susceptible to parvovirus B19 infection, and serologic testing should be repeated in four weeks. Toxoplasma: Routine screening of pregnant people for toxoplasmosis is not recommended by current guidelines and should be limited to immunosuppressed or HIV-positive individuals. An IgG-positive, IgM-negative result typically indicates past infection. Toxoplasma IgM may persist for many months or years after acute infection, and false-positive test results are common. IgG-negative, IgM-positive results suggest possible very recent infection and should be followed to document seroconversion. An IgG-positive, IgM-positive result suggests recent primary infection, and IgG avidity testing is recommended to determine the time since primary infection.

Laboratory assay overview

This test is used to detect TORCH antibodies and aid in the diagnosis of congenital infection.

Laboratory assay overview

This panel may provide antibody-based evidence of a recent or previous infection with Toxoplasma gondii, rubella virus, cytomegalovirus, and/or herpes simplex virus in pregnant individuals. This panel is generally ordered as part of a prenatal evaluation of a patient who is at risk of infection with these microbial agents. However, routine serology testing for these infections as a group has low diagnostic yield for non-specific ultrasound abnormalities of fetuses [1,2]. Some maternal infections during pregnancy may be associated with miscarriage, stillbirth, or fetal abnormalities. These infections may be primary (ie, occur for the first time) or the result of reactivation of prior infections (eg, herpes simplex virus or cytomegalovirus). Infections with these pathogens may have a subclinical course in the mother and transmit to the infant during the prenatal or perinatal period [3]. Testing for infections in pregnant persons should be guided by pathogen-specific clinical features, risk factors, and prevalence [1]. The American Academy of Pediatrics Committee on Fetus and Newborn and American College of Obstetricians and Gynecologists Committee on Obstetric Practice recommend serologic screening for evidence of rubella immunity at the first prenatal visit [3]. Routine serologic screening of pregnant individuals for Toxoplasma and cytomegalovirus is not recommended [3]. Type-specific serologic testing for herpes simplex virus may be useful in the evaluation of risk for infection or confirmation of suspected infection [3,4]. This panel is not recommended for use in documenting newborn congenital infections. In this clinical situation, consider requesting the Torch Panel, Acute. The results of this test panel should be interpreted in the context of pertinent clinical findings. References 1. Fitzpatrick D, et al. Prenat Diagn. 2022;42(1):87-96. 2. Society for Maternal-Fetal Medicine (SMFM), et al. Am J Obstet Gynecol. 2020;223(4):B2-B17. 3. American Academy of Pediatrics Committee on Fetus and Newborn and American College of Obstetricians and Gynecologists Committee on Obstetric Practice. Guidelines for Perinatal Care. 8th ed. 2017. Accessed April 28, 2022. 4. Workowski KA, et al. MMWR Recomm Rep. 2021;70(4):1-187.

Laboratory assay overview

Toxoplasmosis is a parasitic infection caused by the protozoan Toxoplasma gondii. Approximately 23% of the immunocompetent population are asymptomatic carriers of the parasite. The combination of high titers of IgG and IgM antibodies to Toxoplasma gondii is consistent with infection in the last three months. High titers of IgG and low to medium titers of IgM antibodies to Toxoplasma gondii are consistent with infection in the last three to six months.

Quest Diagnostics population reference ranges

Quest Diagnostics calculates these statistical intervals for this specific assay and demographic group, not as universal optimal targets.

Laboratory assay overview

Toxoplasmosis is a parasitic infection caused by the protozoan Toxoplasma gondii. Approximately 23% of the immunocompetent population are asymptomatic carriers of the parasite. High titers of IgG antibodies to Toxoplasma gondii can persist for years. Rising IgG titers after birth, in the absence of a placental leak, are consistent with neonatal infection.

Quest Diagnostics population reference ranges

Quest Diagnostics calculates these statistical intervals for this specific assay and demographic group, not as universal optimal targets.

Laboratory assay overview

Qualitative determination of IgG antibodies to Toxoplasma gondii ( T. gondii ) to aid in the determination of immune status of individuals including pregnant women. If IgG antibody is detected, it is recommended that IgM testing be performed if more precise knowledge of the time of infection is needed (e.g., pregnant women). A positive IgM but a negative IgG result should be viewed with suspicion; the patient should be retested two weeks after the first test. If the patient is pregnant and IgG/IgM positive, an IgG avidity test should be performed. IgG Result IgM Result Interpretation Negative Negative No serological evidence of infection with Toxoplasma. Negative Equivocal Possible early acute infection or false‐positive IgM reaction. Obtain a new specimen for IgG and IgM testing. If results for the second specimen remain the same, the patient is probably not infected with Toxoplasma. Negative Positive Possible acute infection or false‐positive IgM result. Obtain a new specimen for IgG and IgM testing. If results for the second specimen remain the same, the IgM reaction is probably a false‐positive. Equivocal Negative Indeterminate. Obtain a new specimen for testing or retest this specimen for IgG in a different assay. Equivocal Equivocal Indeterminate. Obtain a new specimen for both IgG and IgM testing. Equivocal Positive Possible acute infection with Toxoplasma. Obtain a new specimen for IgG and IgM testing. If results for the second specimen remain the same or if the IgG becomes positive, specimens should be sent to a laboratory with expertise in toxoplasmosis for further testing. Positive Negative Infected with Toxoplasma for six months or more. Positive Equivocal Infected with Toxoplasma for probably more than one year or false‐positive IgM reaction. Obtain a new specimen for IgM testing. If results with the second specimen remain the same, specimens should be sent to a laboratory with expertise in toxoplasmosis for further testing. Positive Positive Possible recent infection within the last 12 months, or false-positive IgM reaction. Specimens should be sent to a laboratory with expertise in toxoplasmosis for further testing.

Laboratory assay overview

The intended use of this test is to determine the presence of Toxoplasma gondii IgG antibody and its avidity.