Test Catalog

Test Id : BRUTA

Brucella Total Antibody Confirmation, Agglutination, Serum

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

Evaluating patients with suspected brucellosis

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


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


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

Brucella Ab, Agglutination, S

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

Brucella abortus

Brucella Serology

Febrile Agglutinins

Specimen Type
Describes the specimen type validated for testing


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

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.25 mL

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

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus OK

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) 14 days
Frozen 14 days

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

Evaluating patients with suspected brucellosis

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

Brucella species are facultative intracellular, gram-negative staining bacilli capable of producing the disease "brucellosis" in humans. Human disease is likely acquired by contact with animals infected with the organism (Brucella abortus, Brucella suis, Brucella melitensis, and occasionally Brucella canis) either by direct contact or by ingestion of meat or milk. The signs and symptoms associated with brucellosis may include fever, night sweats, chills, weakness, malaise, headache, and anorexia. The physical examination may reveal lymphadenopathy and hepatosplenomegaly. A definitive diagnosis of brucellosis is made by recovering the organism from bone marrow, blood, fluid (including urine), or tissue specimens.


In cases of suspected brucellosis, serology may assist in the diagnosis and play a supplementary role to routine culture. Antibodies to Brucella species may not become detectable until 1 to 2 weeks following the onset of symptoms, so serum specimens collected during acute disease may be negative by serology in patients with brucellosis. If serology is performed, the Centers for Disease Control and Prevention currently recommends that specimens testing positive or equivocal for IgG or IgM by a screening enzyme immunoassay be confirmed by a Brucella-specific agglutination method.(1)

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.


Provides information to assist in interpretation of the test results

The Centers for Disease Control and Prevention (CDC) recommends that specimens testing positive or equivocal for IgG or IgM by a screening enzyme immunoassay (EIA) be confirmed by a Brucella-specific agglutination method.(1)


Negative to a titer of 1:40 or higher can be seen in the normal, healthy population. A titer of 1:80 or greater is often considered clinically significant(2); however, a 4-fold or greater increase in titer between acute and convalescent phase sera is required to diagnose acute infection.


The CDC/Council of State and Territorial Epidemiologists case definition for human brucellosis states that the laboratory criteria for diagnosis includes

1. Isolation of Brucella species from a clinical specimen

2. Four-fold or greater rise in Brucella agglutination titer between acute- and convalescent-phase serum specimens collected more than 2 weeks apart and studied at the same laboratory

3. Demonstration by immunofluorescence of Brucella species in a clinical specimen


Positive results by a screening EIA that are not confirmed by Brucella-specific agglutination may represent false-positive screening results. If clinically indicated, a new specimen should be tested after 7 to 14 days.

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

The tube agglutination assay was designed using antigen derived from Brucella abortus, and may not be positive in patients infected with other Brucella species (eg, Brucella canis).


Positive results by Brucella serology are not diagnostic of acute infection, as antibodies may persist for months to years following exposure. To diagnose acute infection, detection of Brucella species in culture is the recommended approach (see BRUCB / Brucella Culture, Blood).


Brucella abortus strain RB51 is used for vaccination of animals in the United States. There are currently no serologic tests to detect an antibody response to strain RB51 in humans. Per Centers for Disease Control and Prevention guidelines, routine clinical serology tests for Brucella do not detect an antibody response to strain RB51. Note that other strains besides RB51 may be used for vaccinating animals outside of the United States.(3)

Supportive Data

Prospective serum specimens (n =114) positive for IgG or IgM antibodies, or both, by a Food and Drug Administration-approved screening enzyme immunoassay (Euroimmun) were tested for Brucella antibodies using tube agglutination (TAT) reagents supplied by the National Veterinary Services Laboratory. The results were compared to those obtained by an outside reference laboratory that used reagents supplied by Remel. Overall percent agreement was 89.5% (102/114).


In addition to prospective sera, a panel of characterized serum specimens (n =14) were tested. Overall agreement was 100% with the expected results.


Sera known to be positive for antibodies to Borrelia burgdorferi (n =5), Chlamydia species (n =1), Coxiella burnetti (n =2), Rickettsia species (n =1), or Epstein-Barr virus (n =11) were tested by the Brucella Ames TAT and all 20 specimens were found to be negative (<1:80). In addition, a serum specimen containing rheumatoid factor (n =1) was tested and found to be negative.

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

1. Centers for Disease Control and Prevention (CDC): Public health consequences of a false-positive laboratory test result for Brucella-Florida, Georgia, and Michigan, 2005. MMWR Morb Mortal Wkly Rep. 2008 Jun 6;57(22):603-605

2. Welch RJ, Litwin CM: A comparison of Brucella IgG and IgM ELISA assays with agglutination methodology. J Clin Lab Anal. 2010;24(3):160-162

3. Gunes H, Dogan M: False-positivity in diagnosis of brucellosis associated with Rev-1 vaccine. Libyan J Med. 2013:8:20417

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

Serially diluted serum is added to an antigen prepared from Brucella abortus strain 1119-3. Agglutination or flocculation is assessed after incubation at 37 degrees C for 48 hours.(Package insert: Animal and Plant Health Inspection Service National Veterinary Services Laboratories, Kirsh D: US Dept of Health, Education, and Welfare; 1973; Cooke FJ, Slack MPE: Gram-negative coccobacilli. In: Cohen J, Powderly WG, Opal SM, eds. Infectious Diseases. 4th ed. Elsevier; 2017:1611-1627)

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


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.

Monday, Wednesday

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.

2 to 7 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

14 days

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


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 Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
BRUTA Brucella Ab, Agglutination, S 19053-8
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
8112 Brucella Ab, Agglutination, S 19053-8

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