Seroprevalence of brucellosis in patients with prolonged fever in Bangladesh

Introduction: This study describes the seroprevalence of human brucellosis among pyretic patients and detection of Brucella abortus DNA from seropositive pyretic patients using real- time polymerase chain reaction (rtPCR) for the first time in Bangladesh. Methodology: Blood samples were collected from 300 pyretic patients from October 2007 to May 2008 and subjected to three serological tests: Rose- Bengal plate test (RBT), standard tube agglutination test (STAT), and indirect enzyme- linked immunosorbent assay (iELISA). Risk factors were identified by multivariate Firth's logistic regression analysis. Brucella genus (BCSP31) and species- specific (IS711) rtPCR were applied to six human sera samples. Results: The seroprevalence of brucellosis among pyretic patients was estimated to be 2.0% (95% confidence interval [CI]: 0.74- 4.30). The odds of brucellosis seropositivity were 8.9 (95% CI: 1.26- 63.0) times higher in pyretic patients who handled goats than those who handled only cattle, whereas the odds of brucellosis seropositivity were 9.7 (95% CI: 1.28- 73.68) times higher in pyretic patients who had backache compared to those without backache. B. abortus DNA was amplified from all six human sera that tested positive by RBT, STAT, and iELISA. As the agreement between the tests was very strong, RBT is recommended as a screening test for the diagnosis of human brucellosis in Bangladesh because it is easier to use, cheaper, and faster. Conclusions: Brucellosis among pyretic patients is common, and B. abortus is responsible for brucellosis in such patients. Pyretic patients who handle goats and those with backaches should be screened for brucellosis.