TORCH 10 Profile

Key Aspects of Toxoplasma IgG Testing

• Purpose: Measures IgG antibodies indicating past infection and potential immunity. It is critical for pregnant women, often part of the TORCH panel to screen for congenital transmission.
• Interpretation:
  • Negative IgG / Negative IgM: No prior exposure, susceptible to infection.
  • Positive IgG / Negative IgM: Past infection, immunity present.
  • Positive IgG / Positive IgM: Potential recent infection or reactivation; further testing (like IgG avidity) might be required.
• Result Timing: IgG levels usually rise 7–14 days after infection, often replacing IgM as the long-lasting antibody.
• Procedure: A blood sample is taken, usually from the arm, with no fasting required.
• Accuracy: Highly accurate but depends on the timing of the test.

What Positive IgG Means

A positive result typically means you have previously been exposed to the parasite. In most healthy individuals, this confirms immunity and that a new infection did not occur during pregnancy.

Why IgG Avidity Tests are Used

If both IgG and IgM are positive, doctors may order a Toxoplasma IgG avidity test to determine how long ago the infection occurred. A "high avidity" result can rule out a recent infection within the past 4 months.

Key Aspects of the Test

• Purpose: Primarily to determine if a patient has been infected with toxoplasmosis recently.
• Procedure: A blood sample is taken, often processed via ELISAs to measure antibody levels.
• Limitations: IgM can remain in the system for up to 18 months post-infection, so a positive result does not always mean the infection occurred within the last few weeks.
• Follow-up: If IgM is positive, further testing (such as a Toxoplasma IgG Avidity test) may be needed to pinpoint the timing of the infection.

What the Results Mean

• Positive IgM: Suggests a recent infection (often within the last 1-2 weeks), although IgM can sometimes persist for months, occasionally resulting in false positives.
• Negative IgM: Suggests no recent infection, or the test was taken too early.
• Borderline/Equivocal: Retesting in 2-3 weeks is often recommended to monitor for changes.

Key Aspects of the Rubella IgG Test

• Purpose: To confirm immunity against rubella, particularly for pregnant women, newborns with suspected congenital defects, and healthcare workers.
• What it Measures: IgG antibodies, which are produced by the body after infection or vaccination, indicating long-term protection.
• Procedure: A standard blood sample is taken from the arm, usually available within 1–2 days.
• Fasting: No, fasting is not required for this test.

When is the Test Recommended?

• Pregnancy Screening: Part of the TORCH panel to protect the fetus.
• Vaccination Check: To confirm immunity, particularly for women planning to conceive.
• Symptom Check: To diagnose active rash or infection symptoms.

Key Aspects of the Rubella IgM Test

• Purpose: Identifies acute, active infection rather than past immunity (which is tested by IgG).
• When to Test: Indicated for fever, rash, joint pain, and suspected exposure, especially during pregnancy to prevent Congenital Rubella Syndrome.
• Procedure: A standard blood sample is taken, usually with no special preparation needed.
• Other Uses: Confirms congenital infection in newborns.

Why the Test is Done

• Pregnancy: To check if a pregnant person has been infected, as primary infection carries risks of passing the virus to the fetus.
• Weakened Immune Systems: For patients with HIV, cancer, or those undergoing transplants, to monitor for reactivation.
• Newborns: To diagnose congenital CMV infection if symptoms are present.

What a Positive Result Means

• Immunity: A positive IgG means you have immunity against that specific strain, though you can still be infected with a different strain.
• Lifelong Presence: The virus remains latent in the body for life after the initial infection.
• Risk Factors: In healthy individuals, it rarely causes symptoms. For immunocompromised individuals, it can cause severe issues, including blindness or pneumonia.

Managing CMV

• Treatment: Healthy people rarely need treatment. Antiviral medications such as ganciclovir or valganciclovir are used to treat serious, active infections in immunocompromised people or symptomatic infants.
• Prevention: Good hygiene, such as frequent handwashing after touching diapers or saliva, is the best prevention, especially for pregnant individuals.

A Cytomegalovirus (CMV) IgM test detects early-response antibodies indicating a recent or active CMV infection. While often causing mild, flu-like symptoms in healthy people, active infection is serious for pregnant individuals and those with weakened immune systems. A positive IgM result, often confirmed with IgG avidity testing, usually suggests an infection within the last 4-20 weeks.

HSV-1 IgG Antibody - Lab test

HSV-1 IgM Antibody - Lab test

HSV-2 IgG Antibody - Lab test

HSV-2 IgM Antibody - Lab test