Evaluation on efficacy of serological and PCR detection for diagnosis of acute human brucellosis

  Objective  To evaluate the efficacy of serological and nested PCR detection for diagnosis of acute human brucellosis.

  Methods  Serum samples of 115 confirmed brucellosis patients were collected for detection of brucella-specific immunoglobulin (Ig) with enzyme-linked immunosorbent assay (ELISA), tube agglutination test (SAT), anti-human Ig test (Coomb′s) and brucella DNA with nested PCR. The detection results of different methods were analyzed statistically.

  Results  The positive rate of brucella-specific Ig was 94.78% (109/115) for ELISA-IgA, 54.78% (63/115) for ELISA-IgM, 87.83% (101/115) for ELISA-IgG, 73.91% (85/115) for SAT, and 98.26% (113/115) for Coomb′s test; and the positive rate of brucella DNA was 8.70% (10/115) for PCR detection. There was a significant difference in the positive rate of the detections using various methods among all the patients (H = 109.63, P < 0.05) and the difference was also significant for the detections among subgroup patients with diverse intervals of < 15 days (χ² = 108.91), 15 − 29 (χ² = 103.04), 30 − 44 (χ² = 50.75), 45 − 59 (χ² = 27.73), and > 60 (χ² = 34.16) between the disease onset and being diagnosed definitely (P < 0.05). The experimental titer differed significantly between SAT and Coomb′s test (Z = − 9.08, P < 0.05).

  Conclusion  The positive detection rate of serological test is significantly higher than that of nested PCR. Therefore, serological detection is still the most effective method for the diagnosis of brucellosis. Coomb′s test could be used as a supplementary method for SAT test.