Brucella Total Antibody Confirmation, Agglutination, Serum
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Evaluating patients with suspected brucellosis
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Brucella Ab, Agglutination, S
Febrile Agglutinins (? FOR SPECIFIC TEST)
Febrile Agglutinins (? FOR SPECIFIC TEST)
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 0.5 mL
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild OK; Gross reject
Mild OK; Gross reject
Mild OK; Gross OK
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Serum||Refrigerated (preferred)||14 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Brucella are facultative intracellular, gram-negative staining bacilli capable of producing the disease "brucellosis" in humans. Human disease likely is 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 drawn during acute disease may be negative by serology in patients with brucellosis. If serology is performed, the Centers for Disease Control and Prevention (CDC) currently recommends that specimens testing positive or equivocal for IgG or IgM by a screening EIA be confirmed by a Brucella-specific agglutination method.(2)
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.
The Centers for Disease Control and Prevention (CDC) recommends that specimens testing positive or equivocal for IgG or IgM by a screening EIA be confirmed by a Brucella-specific agglutination method.(2)
Negative to a titer of > or =1:40 can be seen in the normal, healthy population. A titer of > or =1:80 is often considered clinically significant;(1) 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 drawn >2 weeks apart and studied at the same laboratory, or 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.
Cautions 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/87345 Brucella Culture, Blood).
Prospective serum specimens (n =114) positive for IgG or IgM antibodies, or both, by a U.S. Food and Drug Administration (FDA)-approved screening EIA (Euroimmun, Lubeck, Germany) were tested for Brucella antibodies using tube agglutination (TAT) reagents supplied by the National Veterinary Services (NVS) Laboratory (Ames, IA). The results were compared to those obtained by an outside reference laboratory which uses 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 Provides recommendations for further in-depth reading of a clinical nature
1. Welch RJ, Litwin CM: A comparison of Brucella IgG and IgM ELISA assays with agglutination methodology. J Clin Lab Analysis 2010;24:160-162
2. Public health consequences of a false-positive laboratory test result for Brucella-Florida, Georgia, and Michigan, 2005. MMWR Morb Mortal Wkly Rep June 6;2008:57(22);603-605
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, P.O. Box 844, Ames IA 50010. Kirsh D: U.S. Dept of Health, Education, and Welfare, 1973)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday, Wednesday, Friday; 10 a.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
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's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test uses a standard method. Its performance characteristics were determined 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 Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|8112||Brucella Ab, Agglutination, S||40614-0|