Serology, clinical manifestations and treatment of brucellosis in different age groups.

We prospectively studied 339 patients diagnosed of brucellosis over a six year period in order to evaluate the clinical and serological characteristics of brucellosis in the elderly. 319 patients (94.1%) were under 65 years of age (group A), and 20 patients (5.9%) were older than 65 (group B). No patient in group B developed splenomegaly as opposed to 69 (21.6%) in group A (p less than 0.05). The percentage of positive blood cultures (Brucella melitensis isolated in all cases) was 72.1% in group A and 60% in group B. The mean titer of IgM antibodies measured by indirect immunofluorescence test was significantly lower in the elderly patients, with no other differences in serologic response between the two groups. 103 patients (32.2%) in group A and seven patients (35%) in group B developed some complications; spondylitis was more common and severe among group B patients. There was no therapeutic failure or relapse among patients over 65. We conclude that clinical, bacteriological and serological characteristics and the outcome of brucellosis in the elderly are similar to those seen in younger patients.

[Combined use of rose Bengal and indirect immunofluorescence in the diagnosis of brucellosis]. / Empleo combinado del rosa de Bengala e inmunofluorescencia indirecta en el diagnóstico de la brucelosis.

In the present prospective study we have evaluated the sensitivity, specificity and predictive value of the Bengal rose and indirect immunofluorescence (IIF) in 122 patients with a bacteriological diagnosis of brucellosis. The sensitivity of the Bengal rose was 95.79% and its specificity 98.43%. IIF had a sensitivity of 68.80% and a specificity of 100% when the polyvalent anti-IgS conjugate was used. The combined parallel use of Bengal rose and IIF-IgS resulted in a sensitivity of 89.17% and a specificity of 100%. There was a good correlation between Bengal rose and serum agglutination test (r = 0.72); on the contrary, there were not good correlations between the fluorescent conjugates and Bengal rose, agglutination and Coombs test. In conclusion, the combined use of Bengal rose as a screening test and IIF as a confirmation study is a good diagnostic strategy for human brucellosis.