Toxoplasma Antibody

(redirected from Toxoplasmosis serology)

Toxoplasma Antibody

Synonym/acronym: Toxoplasmosis serology, toxoplasmosis titer.

Common use

To assess for a past or present toxoplasmosis infection and to assess for the presence of antibodies.

Specimen

Serum (1 mL) collected in a gold-, red-, or red/gray-top tube. Place separated serum into a standard transport tube within 2 hr of collection.

Normal findings

(Method: Chemiluminescent immunoassay)
IgMInterpretationIgGInterpretation
Negative0.89 index or lessNo significant level of detectable antibody6.4 IU/mL or lessNo significant level of detectable antibody; indicative of nonimmunity
Indeterminate0.9–1 indexEquivocal results; retest in 10–14 d6.5–7.9 IU/mLEquivocal results; retest in 10–14 d
Positive1.1 index or greaterAntibody detected; indicative of recent immunization, current or recent infection8 IU/mL or greaterAntibody detected; indicative of immunization, current or past infection

Description

Toxoplasmosis is a severe, generalized granulomatous central nervous system disease caused by the protozoan Toxoplasma gondii. The disease is more common in warm, humid climates at lower altitudes. Domestic and related cats are the only known definitive hosts for oocysts of Toxoplasma gondii. Intermediate hosts become infected by ingesting the oocysts which then transform into the tachyzoite form. Tachyzoites migrate to neural and muscle tissue and develop into tissue cysts. Transmission to humans occurs by ingesting undercooked meat of infected animals, handling contaminated matter such as cat litter, drinking contaminated water, receiving a blood product transfusion or organ transplant from an infected donor, or across the placenta from mother to fetus. Immunoglobulin (Ig) M antibodies develop approximately 5 days after infection and can remain elevated for 3 wk to several months. IgG antibodies develop 1 to 2 wk after infection and can remain elevated for months or years. Healthy patients who become infected may not exhibit any symptoms or if symptoms are present they may be vague and common to other conditions. Some patients may develop lesions in the eye which can inflame the retina and form scars upon resolution. Successive reactivation of the inflammation can lead to progressive loss of vision.T. gondii serology is part of the TORCH (toxoplasmosis, other [congenital syphilis and viruses], rubella, cytomegalovirus, and herpes simplex type 2) panel routinely performed on pregnant women. Fetal infection during the first trimester can cause spontaneous abortion or congenital defects such as microcephaly, microphthalmia, hydranencephaly, and hydrocephalus. mmunocompromised individuals are also at high risk for serious complications if infected. While most healthy people recover without treatment, pregnant women, newborns, infants, and immunocompromised patients a receive effective treatment until the worst symptoms have passed and the infection resolves. However, the location of the parasite makes it difficult to completely eradicate with medications. The presence of IgM antibodies indicates acute or congenital infection; the presence of IgG antibodies indicates current or past infection.

This procedure is contraindicated for

    N/A

Indications

  • Assist in establishing a diagnosis of toxoplasmosis
  • Document past exposure or immunity
  • Serological screening during pregnancy

Potential diagnosis

Positive findings in:

  • Toxoplasma infection

Critical findings

    N/A

Interfering factors

    N/A

Nursing Implications and Procedure

Potential nursing problems

ProblemSigns & SymptomsInterventions
Knowledge (Related to recent diagnosis; complexity of treatment; poor understating of provided information; cultural or language barriers; anxiety; emotional disturbance; unfamiliarity with medical management)Possibility that there will not be symptoms if the individual has a healthy immune systemTeach the patient and family that toxoplasmosis infection is caused by the Toxoplasma gondii parasite; teach the patient and family that parasite infection is caused from eating undercooked or contaminated pork, lamb, venison
Infection (Related to inadequate meat preparation [pork, lamb, venison]; accidental ingestion after handling contaminated meat and not washing hands; drinking contaminated water; swallowing contaminated cat feces; accidentally ingesting contaminated soil; pregnancy [mother-child])Absence of symptoms; flu-like symptoms (muscular aches, pains, swollen glands); reduced or blurred vision; eye redness; tearing; eye lesion; infected newborns can have serious eye and brain damage at birthTeach the patient that if the immune system is healthy and the patient is not pregnant, treatment may not be necessary; teach the patient that if eye lesions are present an ophthalmologist may need to be consulted; administer prescribed medications to patients who are HIV positive or are immunosuppressed
Fear (Related to fetal injury secondary to parasite infection during pregnancy)Verbalization of fear; restlessness; increased tension; continuous questioning; increased blood pressure, heart rate, respiratory rateEvaluate verbal and nonverbal indicators of fear; assess for the cause of fear; acknowledge the patient’s awareness of his or her fear; explain all procedures with simple age-appropriate and culturally appropriate language; administer prescribed mild tranquilizer; maintain a confident, assured professional manner in all patient interactions
Noncompliance (Related to refusal to accept new diagnosis; financial instability; cultural norms; complexity of the medical management; lack of knowledge)Insufficient disease management; continued use of raw or contaminated food or water for diet and food preparationAssess the patient’s ability to understand and comply with health recommendations; assess for personal factors that may limit the patient’s ability to understand such as cognitive and hearing factors; assess the level of family support; ensure the patient knows the signs and symptoms related to the disease process; teach correct food preparation and how to prevent at-risk activities related to contamination by soil or cat feces; refer to social services as appropriate

Pretest

  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this test can assist in assessing for toxoplasmosis infection.
  • Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
  • Obtain a history of exposure.
  • Obtain a history of the patient’s immune and reproductive systems, a history of other potential sources of exposure, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
  • Review the procedure with the patient. Inform the patient that several tests may be necessary to confirm the diagnosis. Any individual positive result should be repeated in 3 wk to monitor a change in detectable level of antibody. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Note that there are no food, fluid, or medication restrictions unless by medical direction.

Intratest

  • Potential complications: N/A
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection. Perform a venipuncture.
  • Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
  • Promptly transport the specimen to the laboratory for processing and analysis.

Post-Test

  • Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
  • Recognize anxiety related to test results, and provide emotional support if results are positive and the patient is pregnant and/or immunocompromised. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate. Educate the patient regarding access to counseling services.
  • Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
  • Patient Education

    • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP.
    • Instruct the patient in isolation precautions during time of communicability or contagion.
    • Emphasize the need to return to have a convalescent blood sample taken in 3 wk.
    • Answer any questions or address any concerns voiced by the patient or family.
  • Expected Patient Outcomes

    • Knowledge
    • States understanding that raw or undercooked pork, lamb, or venison can cause a parasitic infection
    • States importance of washing hands after emptying cat litter box to prevent parasitic infection
    • Skills
    • Describes food preparation activities that demonstrate understanding of correct meat preparation and cooking time
    • Demonstrates proficient hand-washing technique
    • Attitude
    • Recognizes the importance of making lifestyle changes to support the health of themselves and family
    • Complies with the recommendation to take special precautions to avoid at-risk activities during pregnancy

Related Monographs

  • Related tests include CMV, fetal fibronectin, rubella, and viral culture.
  • Refer to the Immune and Reproductive systems tables at the end of the book for related tests by body system.
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References in periodicals archive ?
The following diagnostic criteria were used for cerebral toxoplasmosis: multiple intracranial mass lesions (demonstrated on either MRI or CT scan), or a single lesion supported by positive toxoplasmosis serology, or a single lesion with an improvement in clinical or radiological parameters in response to treatment.
7) Positive toxoplasmosis serology (N = 27) 12/13 (92%) 14/14 (100%) Outcome Full recovery 7 (39%) 11 (44%) Disability 9 (50%) 10 (40%) Death 2 (11%) 4 (16%) Adverse events Renal dysfunction 3 (17%) 0 (0%) Liver impairment 2 (11%) 0 (0%) Total 4 (22%) 1 (4%) p Demographics Median age (IQR) 0.
Fifty percent of the case serum samples (78 samples of 156 participants) were randomly retested in a toxoplasmosis serology reference laboratory, Laboratory of Protozoology at the Tropical Medicine Institute of Sgo Paulo.