MYCOPLASMAS (PPLO) AND DISEASE: SERUM ANTIBODY TITERS IN A HOSPITAL POPULATION OF ELDERLY PATIENTS

In a random sample of sera from a predominantly male group of hospital patients with an average age of 67, complement-fixing antibodies were found in 20 per cent to M. hominis type 1, in 16 per cent to Unknown Strain CE 5, in 1 per cent to M. pharyngis and in 2 per cent to M. pneumoniae. These percentages are lower than those reported in the literature for younger populations of patients. Thus the immunological experience with mycoplasmas (pleuropneumonia-like organisms) varies from one population to another. In general, however, the incidence of mycoplasmal infection seems to be lower in older than in younger populations. The findings also indicate that the mere isolation of these organisms from the sera of patients who manifest a disease process does not constitute evidence of an etiological relationship unless other correlates can be established.