Evaluation of serological diagnostic tests for human Brucellosis in an endemic area

Abstract

Objectives: The clinical utility of complementary tests for brucellosis are not clear in many situation. This study aimed to evaluate value of these tests for brucellosis in an endemic area in Turkey. Materials and methods: This study was performed at Çanakkale General Hospital in 2009. In a retrospective approach, records of the patients who evaluated for brucellosis were collected. During the study period, 236 people (131 symptomatic and 105 non-symptomatic) were evaluated for diagnosis of brucellosis. All of the samples from these patients were tested for Brucella antibody seropositivity by RB slide agglutination, standard serum agglutination, Brucella Coombs, BrucellaCapt, and ELISA IgG and IgM tests. Results: In total, 49 symptomatic patients were hospitalized and blood cultures were obtained. Brucella spp. were isolated from nine of them (18.4%).The BrucellaCapt test was found to be the most sensitive for Brucella (74.0%) and close behind it was the Coombs test (72.5%). The sensitivity for the RB test was 48.1%. The ELISA IgG test was found more sensitive for brucellosis than the ELISA IgM test was (65.6% and 49.6%, respectively). All examined tests were found about 100% specific for brucellosis but the RB test was found less specific than the others were (96.1%) Positive predictive value for all tests was about 1 but negative predictive values were only valuable for the Coombs and Brucella Capt test (0.744 and 0.755, respectively). The other serological tests were around and below 0.50, which was weak for negative results. Conclusions: The ELISA IgG and IgM tests were no superior to the other tests. By assessment of receiver operating characteristics (ROC) analysis, the Brucella Coombs and BrucellaCapt tests were found to be the most valuable tests for serological diagnosis of brucellosis in endemic areas. The seronegative tests in the symptomatic patients should be evaluated and repeated in short time.

Keywords

• -

Evaluation of serological diagnostic tests for human Brucellosis in an endemic area

Öz

Anahtar Kelimeler

• -

Kaynakça

1. Joung EJ. Brucella species. In: Mandell GL, Bennett JE, Dolin R, editors. Principles and Practice of Infectious Diseases, 5th ed. Churchill Livingstone, Philadelphia 2000; p 2386.
2. Esel D, Doganay M, Alp E, Sumerkan B. Prospective evaluation of blood cultures in a Turkish university hospital: epidemiology, microbiology and patient outcome. Clin Microbiol Infect 2003; 9: 1038-1044.
3. Spink WW, McCullough NB, Hutchings LM, Mingle CK. A standardized antigen and agglutination technic for human brucellosis. Am J Clin Pathol,1954; 24: 496-8.
4. Mert A, Ozaras R, Tabak F, et al. The sensitivity and specificity of Brucella agglutination tests. Diagn Microbiol Infect Dis 2003; 46: 241-243.
5. Smits HL, Abdoel TH, Solera J, Clavijo E, Diaz R. Immunochromotographic Brucella-specific immunglobulin M and G lateral flow assays for the serodiagnosis of human brucellosis. Clin Diagn Lab Immunol 2003;10: 1141-1146.
6. Vandepitte J. Serological tests. In: Vandepitte J, Verhaegen J, Engback K, Rohner P, Piot P, Hevak CC, editors. Basic Laboratory Procedures in Clinical Bacteriology, 2nd ed WHO Publification, Geneva, 2003; 135-6.
7. Kerr W R, McCaughey W J, Yce JO, et al. Techniques and interpretations in the serological diagnosis of brucellosis in man. J Med Microbiol 1968 ;1:181-193.
8. Young EJ. Brucella spp. In: Gillespie SH, Hawkey PM, editors. Principles and Practice of Clinical Bacteriology, 2nd ed. John Wiley & Sons Ltd, West Sussex, England, 2006: 265-272.

9. Vancelik S, Guraksin A, Ayyildiz A. Seroprevalance of human brucellosis in rural endemic areas in eastern Turkey. Trop Doc 2008; 38: 42-3.
10. Sahin M, Genc O, Unver A, Otlu S. Investigation of bovine brucellosis in the North-eastern Turkey. Trop Anim Health Prod 2008; 40: 281-6.
11. Kose S, Smits HL, Abdoel TH, Ozbel Y. Prevalence of Brucella antibodies in rural and suburban communities in three provinces of Turkey: need for improved diagnosis and prevention. J Infect 2006; 53: 308-14.
12. Cetinkaya Z, Aktepe OC, Ciftci IH, Demirel R. Seroprevalence of human brucellosis in a rural area of Western Anatolia, Turkey. J Health Popul Nutr 2005; 23: 137-141.
13. Ertek M, Yazgı H, Ozkurt Z, Ayyildiz M, Parlak M. Comparison of the diagnostic value of the Standard tube agglutination test and the ELISA IgG and IgM in patients with Brucellosis. Turk J Med Sci 2006; 36: 159-163.
14. Cakan G, Bezirci FB, Kacka A, et al. Assessment of diagnostic enzyme-linked immunosorbent assay kit and serological markers in human brucellosis. Jpn J Infect Dis 2008; 61: 366-370.
15. Araj GF, Brown GM, Haj MM, Madhvan NV. Assessment of Brucellosis Card test in screening patients for brucellosis. Epidem Inf 1988; 100: 389-398.
16. Orduna A, Almaraz A, Prado A, et al. Evaluation of immunocapture-agglutination test (Brucellacapt) for serodiagnosis of human brucellosis. J Clin Microbiol 2000; 38: 4000-4005.
17. Gomez MC, Nieto JA, Rosa C, et al. Evaluation of seven tests for diagnosis of human brucellosis in an area where the disease is endemic. Clin Vacc Immunol 2008; 15: 1031-1033.