FRANC - Clinical: Francisella Tularensis Antibody

Test Catalog

Test ID: FRANC    
Francisella Tularensis Antibody

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Reference Range:  <1:20


Interpretive Criteria:

<1:20 Negative

1:20 - 1:80 Equivocal

> or =1:160 Positive


In the presence of compatible symptoms, a Francisella tularensis antibody titer of 1:160 or greater in an acute specimen supports a presumptive diagnosis of tularemia. However, a titer > or =1:160 may also reflect past infection. An equivocal titer may be due to crossreactive antibodies (Brucella, Yersinia, or Proteus OX19), past infection, or very recent infection. A four-fold rise in titer between acute and convalescent sera is required for definitive serologic diagnosis of tularemia.


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