Tetanus and diphtheria immune status of patients in a family practice.

Sera obtained randomly from 37 patients seen at a family practice center were evaluated for protective antibodies against tetanus and diphtheria using in vivo toxin neutralization methods. The patients' ages ranged from 1 to 99 years. Seventy-four percent and 83 percent of patients were found to have protective antitoxin titers against tetanus and diphtheria, respectively. No significant differences in immune status were detected among different sexes or races. Whereas the mean age of subjects susceptible to tetanus was significantly greater than for those with protective antibody levels, this was not the case with diphtheria. It is postulated that natural diphtheria infection may be responsible for the high degree of protection noted among older subjects surveyed. Practical as well as educational benefits that may be obtained from a study of this nature are discussed.