[Comparative study of 2 serological methods of diagnosis of acute respiratory Mycoplasma pneumoniae infections].

Complement fixation (CF) and haemagglutination (HAP) with M. pneumoniae antigen have proved valuable methods for the etiological diagnosis of acute respiratory infections. Both methods are sensitive and specific, provided purified antigens are used, of the Kenny and Grayston lipid antigen type for CF and the antigen treated by ultrasound and purified by centrifugation for HAP. Concomitant and repeated use of both tests is recommended, following the taking of paired serum samples at 7 to 10 day intervals the first samples being taken within the first ten days of the disease. A single test can only be used for a presumptive serologic diagnosis of acute infection with M. pneumoniae and only if the minimal diagnostic titre is taken into consideration, i.e. 1/64 for CF and 1/160 for HAP.