Comparison of serum and whole blood PCR for diagnosis of human Brucellosis in Iran

Introduction & Objective: Brucellosis is a worldwide zoonosis caused by members of the genus Brucella. It remains a major public health problem in many developing countries. In Iran, human brucellosis is endemic in all parts of the country. Diagnosis of brucellosis is frequently difficult to establish. This is not only because the disease clinically mimics any infectious and non infectious diseases, but also the established diagnostic methods are not always successful in isolating the organisms. The development of new diagnostic techniques that facilitate rapid detection and identification of brucellae and minimize the risk of laboratory infection is of great practical importance. Our aim was to develop a diagnostic PCR assay and define the optimal clinical specimen for this test. Material & Methods: A PCR assay amplifying a 223 bp region within the gene coding for a 31 KD brucella an gen was developed and applied to serum and whole blood samples from 102 suspected patients of brucellosis. Results: Fi y six whole blood samples and sixty eight serum samples out of 102 had positive PCR. The sensitivity of whole blood and serum based PCR assay with samples from suspected pa ents were found to be54% (56/102) and 66% (68/102), respec vely. Conclusion: The PCR assay sensi vity was higher with serum samples (66%) than with whole blood samples (54%).These results suggest that serum is the sample of choice, which should be used preferentially over whole blood for the diagnosis of human brucellosis by PCR