What are the follow-up laboratory tests for Brucellosis (Brucella infection)?

From the Guidelines

For Brucella follow-up labs, I recommend repeat blood cultures, monitoring of complete blood count (CBC), liver function tests (LFTs), and erythrocyte sedimentation rate (ESR) every 2-4 weeks during treatment, as well as checking serum agglutination titers at the end of treatment and 3-6 months later. The provided evidence from the 2015 Infectious Diseases Society of America (IDSA) clinical practice guidelines for the diagnosis and treatment of native vertebral osteomyelitis in adults 1 does not directly address the follow-up laboratory tests for Brucellosis. However, based on general medical knowledge and the principles of managing infectious diseases, the recommended follow-up labs are crucial for assessing treatment efficacy and monitoring for complications.

• Repeat blood cultures at 2-4 weeks after starting treatment confirm clearance of bacteremia.
• Monitoring CBC, LFTs, and ESR every 2-4 weeks during treatment detects potential side effects of antibiotics and tracks the overall inflammatory response.
• Checking serum agglutination titers at the end of treatment and 3-6 months later provides a quantitative measure of antibody response, with declining titers indicating successful treatment.
• Performing imaging studies (e.g., CT, MRI) if there's suspicion of focal complications like endocarditis or osteomyelitis is also essential.
• Considering testing renal function if using potentially nephrotoxic antibiotics is necessary to prevent further complications. These follow-up labs help assess treatment efficacy and monitor for complications, allowing for timely adjustments to treatment if needed, and improving outcomes in this potentially chronic infection.

From the Research

Follow-up Laboratory Tests for Brucellosis

The follow-up laboratory tests for Brucellosis (Brucella infection) include:

• Standard agglutination test (SAT) and 2-mercaptoethanol (2-ME) tests, which are usually used in the follow-up of treated cases of human brucellosis 2
• Rose Bengal Plate Test (RBPT), Standard Tube Agglutination Test (SAT), and enzyme-linked immunosorbent assay (ELISA) to detect Brucella antibodies 3
• Immunofluorescence staining (IFS) to detect intracellular Brucella antigens in peripheral blood mononuclear cells (PBMCs) 3
• Brucella Enzyme Immunoassay and the Standard Agglutination with 2-Mercaptoethanol Test for the diagnosis and monitoring of brucellosis 4
• Serum (tube) agglutination test (SAT) to measure antibody titers 5
• Real-time quantitative polymerase chain reaction (Q-PCR) to monitor the evolution of Brucella melitensis DNA load during therapy and post-therapy follow-up 6

Laboratory Tests for Monitoring Therapeutic Efficacy

The laboratory tests used for monitoring therapeutic efficacy of brucellosis infection include:

• SAT and 2-ME tests to monitor the levels of these tests after clinical cure in cases of brucellosis 2
• IFS to detect intracellular Brucella antigens in PBMCs 3
• Brucella Enzyme Immunoassay and the Standard Agglutination with 2-Mercaptoethanol Test to monitor the diagnosis and treatment of brucellosis 4
• Q-PCR to monitor the evolution of Brucella melitensis DNA load during therapy and post-therapy follow-up 6

Interpretation of Laboratory Test Results

The interpretation of laboratory test results for brucellosis includes:

• Serologic cure is considered in the event of a SAT titer decrease to < or =1:160 or a 2-ME decrease to <1:80 2
• The probability of serologic cure for patients with SAT titers < or =1:640 was higher than for those >1:640 2
• The probability of serologic cure for patients with 2-ME titers < or =1:320 was higher than for those >1:320 2
• The IgM ELISA showed higher sensitivity and specificity than the SAT-2Me for the diagnosis and monitoring of brucellosis 4