The sensitivity and specificity of Brucella agglutination tests

Area of Science:

• Infectious Diseases
• Microbiology
• Immunology

Background:

• Brucellosis, a systemic infection by Brucella bacilli, presents diverse clinical features.
• Differential diagnosis of brucellosis often includes various infectious and non-infectious diseases.
• Accurate diagnostic tools are crucial for differentiating brucellosis from conditions with overlapping symptoms.

Purpose of the Study:

• To evaluate the positivity rate of Brucella agglutination tests.
• To assess the diagnostic accuracy in culture-positive brucellosis cases.
• To determine the efficacy in distinguishing brucellosis from clinically mimicking diseases.

Main Methods:

• Serum samples from 30 culture-positive brucellosis patients were analyzed.
• Samples from 280 patients with mimicking diseases (e.g., tuberculosis, malaria, autoimmune disorders) were included.
• Brucella agglutination tests (Rose-Bengal and Wright) were performed.

Main Results:

• All brucellosis patients showed positive Rose-Bengal and Wright tests (titer ≥ 1/160).
• False positive results were minimal in mimicking diseases: one malaria, one lymphoma (1/40), and one typhoid fever (1/20).
• Agglutination tests remained negative in the majority of non-brucellosis cases.

Conclusions:

• Brucella agglutination tests demonstrate high sensitivity and specificity for brucellosis diagnosis.
• These agglutination tests are reliable for excluding brucellosis in patients with similar clinical features.
• The study confirms the clinical utility of agglutination tests in the etiological diagnosis of brucellosis.