Serology for tularemia is a blood test that checks for infection due to a bacterium called Francisella tularensis, which causes the disease tularemia.
How the Test is Performed
A blood sample is drawn from a vein.
The sample is sent to a laboratory where it is examined for Francisella antibodies using a method called serology. This method checks if your body has produced substances called antibodies to a specific foreign substance (antigen), in this case Francisella tularensis. Antibodies defend your body against bacteria, viruses, and fungi. If antibodies are present, they are in the serum of your blood. Serum is the liquid portion of blood.
How to Prepare for the Test
There is no special preparation.
How the Test will Feel
When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the Test is Performed
This blood test is done when tularemia is suspected.
Abscence of antibodies to F. tularensis is normal.
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results
What Abnormal Results Mean
If antibodies are detected, there has been exposure to F. tularensis.
The presence of these antibodies means you have a current or past infection with F. tularensis. In some cases, a single high level of antibodies that are specific to F. tularensis means you have an infection.
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
During the early stage of an illness, few antibodies may be detected. Antibody production increases during the course of an infection. For this reason, this test may be repeated several weeks after the first test.
Tularemia test; Serology for Francisella tularensis
Schaffner W. Tularemia and other Francisella infections. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 319.
Penn RL. Francisella tularensis (Tularemia). In: Mandell GL, Bennett JE, Dolin R, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier Churchill-Livingstone; 2009:chap 227.
Update Date 5/19/2013
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial Team.