TPHA (Treponema pallidum)

The TPHA (Treponema pallidum) test detects antibodies to Treponema pallidum, the bacterium responsible for syphilis, and is essential for the accurate diagnosis of this disease. At the IntroLab in Belgrade, we offer this service as part of our comprehensive range of sexually transmitted disease tests, providing fast, accurate, and discreet analysis.

What is TPHA?

TPHA, which stands for Treponema Pallidum Hemagglutination test, is a laboratory test designed to detect antibodies against the Treponema pallidum bacterium. This spiral-shaped bacterium causes syphilis, a serious sexually transmitted disease that can lead to long-term and potentially life-threatening consequences if not treated. The test works by detecting a hemagglutination reaction, where erythrocytes (red blood cells) clump together in the presence of antibodies. The specific antibodies detected by the TPHA test are produced in response to an infection with Treponema pallidum.

The TPHA test is highly specific and sensitive, often serving as a reference method for confirming a syphilis diagnosis. While several tests can detect syphilis, TPHA is particularly valuable because it can identify the infection at different stages of the disease, including both early and late stages. However, it’s important to note that the presence of antibodies detected by the TPHA test may indicate a past, previously treated infection. Therefore, a positive TPHA test often requires additional diagnostic testing to confirm an active infection.

When is the TPHA (Treponema pallidum) test performed?

The TPHA test is usually conducted when there is a suspicion of syphilis based on symptoms, results from other tests, or potential exposure to the infection. It is also recommended for pregnant women as part of prenatal screening to prevent transmission of the disease to the fetus. Individuals with multiple sexual partners, those whose partners have syphilis, or those who engage in unprotected sex should consider getting tested.

Stages of syphilis: Understanding disease progression

Syphilis progresses through several stages, each with distinct symptoms and potential complications:

• The primary stage of syphilis typically occurs two to six weeks after exposure to the Treponema pallidum bacterium. It is marked by one or more hard, painless sores (chancres) at the site where the bacteria entered the body. These sores most commonly appear in the genital area but can develop anywhere on the body.
• The secondary stage of syphilis follows several weeks to several months after the primary stage. Symptoms during this phase can be more widespread and may include a rash, fever, fatigue, headache, muscle and joint pain, hair loss, and swollen lymph nodes.
• The tertiary stage of syphilis can develop years or even decades after the initial infection. This stage occurs in individuals who have not been treated, and symptoms can vary depending on which organs are affected.

Potential outcomes of the tertiary stage

The tertiary stage of syphilis can result in severe complications, including serious cardiovascular problems, neurological symptoms such as paralysis, vision issues, dementia, and mental disorders, as well as damage to internal organs. Therefore, early detection and treatment of syphilis are essential to prevent these serious outcomes.

Congenital syphilis

Congenital syphilis is a serious condition that occurs when Treponema pallidum is transmitted from mother to child during pregnancy or childbirth. This can result in miscarriage, stillbirth, or various physical and mental disabilities. Therefore, it is crucial for all pregnant women to be tested for syphilis, including through the TPHA test.

How to interpret the results

A negative TPHA test suggests the absence of antibodies to Treponema pallidum, indicating that an infection is unlikely. A positive result shows the presence of antibodies, which could indicate a possible infection. However, since antibodies can remain in the body for years after syphilis has been treated, a positive result does not necessarily mean an active syphilis infection. Additional testing may be required.

Test specificity and subtypes

It’s important to understand that there are several different tests for syphilis, including the RPR (Rapid Plasma Reagin) and VDRL (Venereal Disease Research Laboratory) tests. These tests detect different types of antibodies and may be used at various stages of the disease. Your doctor will select the most appropriate test based on your symptoms, medical history, and potential exposure.