What is Salmonella Typhi IgM?

Typhi Dot test is done for Salmonella typhi. This test detects IgM antibodies against Salmonella typhi. This test is not a quantitative test. It only detects the presence or absence of Salmonella typhi.

Why is Salmonella Typhi IgM done?

The Typhi dot test is done:

• In case of signs or symptoms of typhoid (enteric) fever such as headache, high fever, abdominal pain, diarrhea, weight loss, or skin rashes
• As a part of the fever panel

What does Salmonella Typhi IgM Measure?

The Typhi dot test measures IgM Antibody against Salmonella typhi. These antibodies are produced against the outer membrane protein (OMP) of Salmonella typhi. This test usually shows results within 2-3 days of infection. It identifies IgM Antibody separately. The presence of IgM antibodies indicates a recent infection while the presence of IgG antibodies indicates a remote infection.

As this test is not a quantitative test, it only detects the presence or absence of Salmonella typhi. Widal test is advised in case titers (small portion) of specific antibodies are required.

Interpretations

• Positive Salmonella typhi IgM test suggests recent infection with bacteria Salmonella Typhi causing typhoid fever
• Negative Salmonella typhi IgM test usually indicates no infection with the bacteria