The serological diagnosis of Mycoplasma pneumoniae infection: a comparison of complement fixation, haemagglutination and immunofluorescence

A total of 193 sera were examined for antibody to Mycoplasma pneumoniae by three techniques - complement fixation (CF), haemagglutination (HA) and immunofluorescence (IF), the last method being used to assess IgM, IgG and IgA antibodies. The most reliable single test for diagnosis was HA, and the most useful combination of tests was HA with IF (IgM and IgG). The IgA IF was not found to be diagnostically helpful.