بررسي قدرت تشخيصي آزمون روز بنگال در مقايسه با الايزا در بروسلوز حاد و مزمن

Rose Bengal test versus ELISA in the diagnosis of acute and chronic brucellosis

Background: Since Brucellosis has a high incidence in Iran, a quick, sensitive and specific diagnosis for immediate therapy is necessary. This study was conducted on patients with Brucellosis in the city of Zanjan in years 2002-2003 to compare the diagnostic values of rapid Rose Bengal test and the selective ELISA assay. Materials and Methods:. All patients that were suspicious of Brucellosis and were refered to the laboratory by specialists were entered to the study. In order to conduct Rose Bengal test and to measure the specific IgG and IgM antibodies by ELISA, 5 ml blood was taken from each patient and the serums kept at -20°C until use. Each sample was examined by these methods in duplicate and the sensitivity, specificity and the positive and negative predictability values were calculated. Results: Out of 176 patients, 92 (52.3%) were males and 84 (47.7%) were females. The age of the patients was between 15 to 65 years old with the average of 18-40 years. 72.4% patients were from rural and 27.6% from urban areas. In 24 cases (13.3%), the Rose Bengal test was positive, while with ELISA assay, 72 patients (40.9%) were positive. The sensitivity, specificity and positive and negative predictive values of Rose Bengal test were compared to IgM ELISA values that were 100, 95.6, 70.8 and 100%, and with that of IgG ELISA values were 36.9, 100, 100 and 73%, respectively. Conclusion: In acute phase of Brucellosis, the sensitivity of Rose Bengal test is equal to ELISA assay and is recommended for this stage. However, in chronic phase of the disease, the sensitivity is low and Rose Bengal test is not suggested. For this stage of the disease the ELISA assay is recommended.