What is Typhi Dot?
Typhi Dot test is done for Salmonella typhi. This test detects IgM and IgG antibodies against Salmonella typhi. This test is not a quantitative test. It only detects the presence or absence of Salmonella typhi.
Why is Typhi Dot 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 fever panel
What does Typhi Dot Measure?
The Typhi dot test measures IgM and IgG antibodies 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 and IgG antibodies 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 is required.
Interpreting Typhi Dot results
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