Tetanus incidence and immunity in Poland.

The level of tetanus antibody was determined with the passive hemagglutination method in 503 sera of 10 to 90-year-old persons. Immunity to tetanus was age-dependent: the percentage of immune persons amounted to 90%-100% in persons below 40 years and then declined to 70% and 60% in persons in the 40-50 and above 50 year-old groups, respectively. Males above 30 years are better immunized than females. The comparison of the results of the present study with results of several periodic surveys performed in the last 27 years showed gradually increasing immunity level in all age groups. The findings are in agreement with age-dependent incidence of tetanus, which has become now, in Poland, a disease primarily of older people.