The Rose Bengal Test in Human Brucellosis: A Neglected Test for the Diagnosis of a Neglected Disease

Brucellosis is a highly contagious zoonosis affecting livestock and human beings. The human disease lacks pathognomonic symptoms and laboratory tests are essential for its diagnosis. However, most tests are difficult to implement in the areas and countries were brucellosis is endemic. Here, we compared the simple and cheap Rose Bengal Test (RBT) with serum agglutination, Coombs, competitive ELISA, Brucellacapt, lateral flow immunochromatography for IgM and IgG detection and immunoprecipitation with Brucella proteins. We tested 208 sera from patients with brucellosis proved by bacteriological isolation, 20 contacts with no brucellosis, and 1559 sera of persons with no recent contact or brucellosis symptoms. RBT was highly sensitive in acute and long evolution brucellosis cases and this related to its ability to detect IgM, IgG and IgA, to the absence of prozones, and to the agglutinating activity of blocking IgA at the pH of the test. RBT was also highly specific in the sera of persons with no contact with Brucella. No test in this study outperformed RBT, and none was fully satisfactory in distinguishing contacts from infected patients. When modified to test serum dilutions, a diagnostic titer >4 in RBT resulted in 87.4% sensitivity (infected patients) and 100% specificity (contacts). We discuss the limitations of serological tests in the diagnosis of human brucellosis, particularly in the more chronic forms, and conclude that simplicity and affordability of RBT make it close to the ideal test for small and understaffed hospitals and laboratories

The Impact of Acute Brucellosis on Mean Platelet Volume and Red Blood Cell Distribution

Background: Brucellosis is an inflammatory disease which may infect any organs or systems in the body. Mean Platelet Volume (MPV) is one of the most frequently used surrogate markers of platelet function. It reveals the presence of disease activity in many inflammatory diseases. Red blood cell distribution width (RDW) is a parameter that measures variation in red blood cell size or red blood cell volume. Its predictive value approves inflammatory and infectious diseases. Objectives: The current study aimed to determine the assessment levels of red blood cell distribution in cases with acute brucellosis. Patients and Methods: The current study investigated whether MPV and RDW played any roles in acute brucellosis diagnosis. The study was conducted from 2008 to 2014 through prospective examination of the inflammatory markers found in adult patients with acute brucellosis. Results: The follow-up within the year after treatment was examined. The values of age, gender, leukocyte count, C-reactive protein, RDW and MPV were recorded. The study included 351 subjects, 250 of them in the acute brucellosis group and 101 in the control group. The mean MPV levels were 7.64 +/- 1.30 fL, and 7.67 +/- 1.29 fL in the acute brucellosis and control groups, respectively (P > 0.05). The mean CRP levels were 32.57 +/- 53.20 mg/dL, and 4.81 +/- 4.89 mg/dL in the acute brucellosis and control groups, respectively (P 0.05). Conclusions: While the CRP value was in patients with acute brucellosis in the current study, the MPV, RDW and leukocyte counts were within the normal range. CRP value remains the most valuable inflammatory marker in cases of acute brucellosis