Serum is the preferred clinical specimen for diagnosis of human brucellosis by PCR

Human brucellosis poses a significant public health problem in many develop ing countries and requires fast and accurate diagnosis. A PCR assay amplify ing part of the 31-kDa Brucella abortus antigenic protein gene sequence was developed and applied to whole-blood and serum samples from 31 brucellosis patients and 45 healthy individuals. All patients except one had detectabl e Brucella DNA in either whole blood or serum (combined sensitivity, 97%), but, the assay sensitivity was higher with serum samples (94%) than with wh ole-blood samples (61%). The assay specificity was excellent (100%). A conf irmatory PCR assay targeting another Brucella gene region (omp-2) was also developed but lacked sensitivity. Serum is the optimal specimen for the dia gnosis of brucellosis by PCR, a choice that leads to assay simplification a nd shortens turnaround time.