Test Catalog

Test Id : TULI

Francisella tularensis Antibody, IgM and IgG, Technical Interpretation, Serum

Useful For
Suggests clinical disorders or settings where the test may be helpful

Interpretation for the aid in the diagnosis of tularemia caused by Francisella tularensis

 

This assay should not be used as a test of cure as it is not quantitative and patients may remain seropositive for months to years following resolution of disease.

Method Name
A short description of the method used to perform the test

Only orderable as part of a profile. For more information see Francisella tularensis Antibody, IgM and IgG, ELISA, Serum.

 

Technical Interpretation

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

F. tularensis Interpretation

Aliases
Lists additional common names for a test, as an aid in searching

Tularensis

Tick-borne

Rabbit fever

Glandular fever

Specimen Type
Describes the specimen type validated for testing

Serum

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Only orderable as part of a profile. For more information see Francisella tularensis Antibody, IgM and IgG, ELISA, Serum.

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject
Other Heat inactivated specimen

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
Frozen 30 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Interpretation for the aid in the diagnosis of tularemia caused by Francisella tularensis

 

This assay should not be used as a test of cure as it is not quantitative and patients may remain seropositive for months to years following resolution of disease.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Francisella tularensis is a small, intracellular, coccobacillary Gram negative bacterium and is an obligate pathogen in animals and humans, primarily maintained in rabbits, hares, cats, ticks and deerflies. F tularensis is found throughout North America and parts of Asia, and similar to Brucella species is considered a potential agent of bioterrorism. Human infection with F tularensis usually occurs through inhalation of infected aerosols, ingestion of contaminated meat or water, handling of diseased or sick animals, or through the bite of an infected arthropod (eg, tick, deerflies).

 

Following a 3 to 5 day incubation period, the clinical manifestations of infection with F tularensis differ primarily depending on the site and route of infection. The most common form of disease is ulceroglandular (45%-80% of cases), which is associated with an arthropod (or animal) bite or another cause of skin barrier compromise. This leads to development of a painful papule which ultimately ulcerates following which the bacterium enters the lymphatic system. Glandular tularemia is similar in presentation to ulceroglandular disease, however it lacks the ulceration and more frequently causes septicemia. Other, less frequent clinical manifestations include oculoglandular (Parinaud syndrome), oropharyngeal and gastrointestinal disease, pneumonic or typhoidal tularemia.

 

Diagnostic testing options for F tularensis primarily include culture and serology. Physicians suspecting tularemia should collect appropriate specimens (eg, skin lesion biopsy, lymph node aspirates, etc.) promptly and send for culture. The microbiology laboratory should be alerted to the possibility of F tularensis to ensure that appropriate safety measures are taken to protect the laboratory technologists. Growth on culture is a definitive means of making a diagnosis of tularensis. Serologic testing may be used to support a diagnosis of current or recent tularensis in patients who are IgM positive, or seroconvert to IgM, or IgG positive in paired sera collected 2 to 3 weeks apart.

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.

Only orderable as part of a profile. For more information see Francisella tularensis Antibody, IgM and IgG, ELISA, Serum.

Interpretation
Provides information to assist in interpretation of the test results

IgM Result

IgG Result

Interpretation

Negative

Negative

No antibodies to Francisella tularensis detected. Antibody response may be negative in samples collected too soon following infection/exposure. Repeat testing on a new sample if clinically indicated.

Positive

Negative

IgM class antibodies to F tularensis detected, suggesting current or recent infection. Repeat testing in 2 to 3 weeks to detect seroconversion of IgG may be considered to confirm the diagnosis.

Positive

Borderline

Borderline

Negative

Questionable presence of IgM antibodies to F tularensis. Consider repeat testing in 1 to 2 weeks.

Borderline

Positive

IgG class antibodies to F tularensis detected suggesting recent or past infection. Clinical correlation alongside presentation, exposure history and other laboratory findings required.

Borderline

Borderline

Questionable presence of IgM and IgG class antibodies to F tularensis. Consider repeat testing in 1 to 2 weeks.

Positive

Positive

IgM and IgG class antibodies to F tularensis detected suggesting current, recent or past infection. Clinical correlation alongside presentation, exposure history and other laboratory findings required.

Negative

Positive

IgG class antibodies to F tularensis detected suggesting recent or past infection. Clinical correlation alongside presentation, exposure history and other laboratory findings required.

Negative

Borderline

Questionable presence of IgG antibodies to F tularensis. Consider repeat testing in 1 to 2 weeks.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

False negative results may occur in samples collected too soon following symptom onset, prior to the development of a detectable immune response. Repeat testing on new samples collected 2 to 4 weeks later may be helpful.

 

False positive results may occur in patients previously or currently infected with Brucella species. Other less frequent causes of cross-reactivity that have been reported include prior infection with Yersinia, Salmonella or Legionella species.

 

IgM-class antibodies may be detectable as soon as 1 week after symptom onset and may remain detectable for multiple years following resolution of disease in some individuals. Therefore, an IgM positive result may not indicated current or recent infection in some cases.

 

There are multiple subspecies of Francisella tularensis, including F tularensis subspecies tularensis, F tularensis subspecies holarctica and F tularensis subspecies novicida that are found throughout the norther hemisphere, including in the United States. The IgM and IgG anti-F tularensis ELISA tests used at Mayo Clinic Laboratories are based on the lipopolysaccharide (LPS) antigen of F tularensis. Although not directly tested, previous studies indicate that there are no antigenic differences between the LPS of F tularensis subspecies tularensis and the other subspecies. Therefore, these assays should not be used to differentiate between infection with the various F tularensis subspecies.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Petersen JM, Schriefer ME, Araj GE: Francisella and Brucella. In Manual of Clinical Microbiology. 12th Edition. 2019

2. Nigrovic LE, Wingerter SL: Tularemia. Infect Dis Clin North Am. 2008; 22(3): 489-504. doi: 10.1016/j.idc.2008.03.004

Method Description
Describes how the test is performed and provides a method-specific reference

Automated interpretation of IgM and IgG antibody results for Francisella tularensis.

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Tuesday and Thursday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 day

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports