[Recent trends in the serologic diagnosis of pertussis].

Anti-whooping cough agglutinin titrations were performed in various groups of children by employing a special antigen and a microtechnique. Moderate agglutinating titers were detected in the first trimester of life and were interpreted as transmitted from the mother. Rare and moderate titers were observed in a group of children of school age, randomly selected and non institutionalized, while, on the contrary, an analogous institutionalized group showed more frequent and higher rate of antibodies.