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HelpTest Code BRUTA Brucella Total Antibody Confirmation, Agglutination, Serum
Reporting Name
Brucella Ab, Agglutination, SUseful For
Diagnosis of brucellosis
Method Name
Agglutination
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumSpecimen Required
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
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.
Specimen Minimum Volume
0.25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 14 days | |
| Frozen | 14 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
Reference Values
<1:80
Day(s) Performed
Wednesday, Friday
CPT Code Information
86622
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| BRUTA | Brucella Ab, Agglutination, S | 19053-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8112 | Brucella Ab, Agglutination, S | In Process |
Clinical Information
Brucella species are facultative intracellular, gram-negative bacilli that cause 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 in 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.
Interpretation
The Centers for Disease Control and Prevention 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.
Titers below 1:80 are seen in normal, healthy populations. Titers of 1:80 or greater are often considered clinically significant (1); however, a 4-fold or greater increase in titers between acute and convalescent phase sera is required to diagnose acute infection.
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
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.(2)
Method Description
Serially diluted serum is added to an antigen prepared from Brucella abortus strain 1119-3. Agglutination or flocculation is assessed after incubation at 37° 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)