[Relationship between the duration of the clinical course of human brucellosis and the avidity of specific IgG antibodies].

The aim of this work was to relate the avidity of specific IgG antibodies with the time of evolution of human brucella infection. IgG anti-brucella antibodies were measured using an ELISA assay with 8 M urea in 17 patients with recent active brucellosis (group I), 31 patients with chronic active brucellosis (group II) and 120 asymptomatic patients with past brucellosis (group III). Twelve patients of group I (70.6%), three of group II (9.7%) and none in group III had low avidity antibodies against Brucella. It is concluded that these antibodies have a high diagnostic efficiency for recent Brucella infections.