Sabin feldman Dye test is used to demonstrate infection with?

NEET PG
#1

Sabin feldman Dye test is used to
demonstrate infection with ?
a) Filaria
b) Toxoplasma
c) Histoplasma
d) Ascaris
Correct Answer - B
Ans. is •b’ i.e., Toxoplasma
The polyclonal IgG antibodies evoked by infection are parasiticidal in
vitro in the presence of serum complement and are the basis for the
Sabin - Feldman dye test.
Laboratory diagnosis of toxoplasmosis
Laboratory diagnosis can be made by

  1. Microscopic demonstration of the parasite
  2. Isolation of the parasite by animal inoculation or tissue culture.
  3. Polymerase chain reaction
  4. Serology
    The most common method of laboratory diagnosis
    Persons should initially be tested for the presence of Toxoplasma
    specific IgG antibodies to determine their
    immune status. A positive IgG titre indicates infection with the
    organism at sometime ( recent or past).
    Then an IgG positive person should have an IgM test. A negative
    test essentially excludes recent infection. However, a positive IgM
    test does not always mean a recent infection because toxoplasma
    specific IgM antibodies may persist for months to year following
    primary infection. Therefore :?
    Negative IgM with positive IgG always means a past infection.
    Positive IgM with positive IgG indicates possibility of recent infection,
    but not with 100% surety. It may or may not be recent infection. To
    differentiate between recent and past infection, IgG avidity test is
    used.
    It is worth noting here that a third situation is also possible when IgM
    test is positive but IgG test is negative. In this situation a second
    sample should be taken after 2-4 weeks and should be tested :?
    If the second sample is positive for IgG and IgM, it indicates that the
    first sample was taken early in the disease when IgG was not yet
    developed.
    If the second sample is still negative for IgG with positive IgM, it
    indicates false positive IgM test.
    Tests for IgG antibodies
    IgG ELISA/EIA
    Sabin- Fieldman dye test
    IgG indirect flourscent
    antibody test(IgG IFA)
    Diffemtial agglutination (
    AC/HS)
    Avidity test
    Tests for IgM antibodies
    IgM indirect flourscent antibody
    test (IgM IFA)
    Double sandwich ELISA
    IgM capture EIA
    Immunosorbant agglutination
    assay ( ISAGA)