Toxoplasma gondii antibodies, IgG, IgM

A toxoplasmosis test is used to detect a current or past infection with the microscopic parasite Toxoplasma gondii. Most often it may be performed for:

  • A woman prior to or during a pregnancy to determine if she has been previously exposed to Toxoplasma gondii and during a pregnancy if exposure is suspected.
  • An individual who has a weakened immune system (immunocompromised) and has flu-like symptoms.
  • A person who has signs or symptoms of toxoplasmosis.
  • An unborn baby, in which case, amniotic fluid may be tested.

When someone is exposed to T. gondii, their immune system responds by producing antibodies to the parasite. Two classes of Toxoplasma antibodies may be found in the blood: IgM and IgG.

IgM antibodies are the first to be produced by the body in response to a Toxoplasma infection. They are present in most individuals within a week or two after the initial exposure. IgM antibody production rises for a short time period and declines. Eventually, sometimes months after the initial infection, the level (titer) of IgM antibody falls below a detectable level in most people. Additional IgM may be produced when dormant T. gondii is reactivated and/or when a person has a chronic infection.

IgG antibodies are produced by the body several weeks after the initial infection and provide long-term protection. Levels of IgG rise during the active infection, then stabilize as the Toxoplasma infection resolves and the parasite becomes inactive. Once a person has been exposed to T. gondii, that person will have some measurable amount of IgG antibody in their blood for the rest of their life.

  • Sample of blood serum
  • We perform the test daily