What is Serodia test?

The Serodia Treponema pallidum particle agglutination (TP-PA) test is a treponemal test for the serologic detection of antibodies to the various species and subspecies of pathogenic Treponema, the causative agents of syphilis, yaws, pinta, bejel, and endemic syphilis.

What is particle agglutination test for HIV?

A particle agglutination (PA) test, the Serodia HIV-1/2 test (Fujirebio, Inc., Tokyo, Japan), is a low-cost, simple-to-perform agglutination assay capable of detecting antibodies to HIV-1 and HIV-2.

What is the principle of agglutination test?

The reaction between a particulate antigen and an antibody results in visible clumping called agglutination. Antibodies that produce such reactions are known as agglutinins. The principle of Agglutination reactions are similar to precipitation reactions; they depend on the cross linking of polyvalent antigens.

What is the name of HIV antibody?

An antigen test checks your blood for an HIV antigen, called p24. When you’re first infected with HIV, and before your body has a chance to make antibodies to the virus, your blood has a high level of p24. The p24 antigen test is accurate 11 days to 1 month after getting infected.

What causes a false positive TPPA?

These false-positive results are often transient with unknown cause. False-positive results may occur in association with other underlying illnesses. Serodia TP-PA may be reactive in persons from areas endemic for yaws or pinta. Serodia TP-PA performs best in populations at risk for T pallidum infection.

What does a positive FTA-ABS mean?

A positive FTA-ABS is often a sign of a syphilis infection. This test result will remain positive for life even if syphilis has been adequately treated. Therefore, it cannot be used to monitor the treatment of syphilis or determine that you have active syphilis.

Why is latex agglutination testing commonly used?

Latex agglutination testing, also called latex fixation, is a diagnostic study that is widely used as a laboratory method to identify certain antibodies and antigens. The test uses a variety of body fluids including blood, urine, saliva and cerebrospinal fluid, which are dependable on what type of sample is needed.

What other particles can be used in agglutination assays?

Agglutination tests detect antibody or antigen and involve agglutination of bacteria, red cells, or antigen- or antibody-coated latex particles. They rely on the bivalent nature of antibodies, which can cross-link particulate antigens.

What is window period for p24 antigen test?

The first HIV protein (antigen) that can be measured is p24 (from 1 to 8 weeks after exposure). Viral load and p24 tests are not accurate for diagnosing early HIV if the results are negative. An HIV antibody response can be detected as early as two weeks in a few people and in more than 99.9% of people by 12 weeks.

What is a seroconversion rate?

Seroconversion is the transition from the point of viral infection to when antibodies of the virus become present in the blood. Given that many diagnostic tests use the presence of antibodies to infer illness, understanding seroconversion becomes a very important part of immunology and virology.