Tetanus immunity in emergency department patients.

Demographic data and blood samples were collected from 278 patients seen at two District of Columbia emergency departments, and tetanus antitoxin assays by hemagglutination were performed at the Centers for Disease Control. Twenty-seven patients (10%) had antibody levels below the 0.01 U/mL considered protective. Four demographic characteristics were different in the patients with inadequate immunity (in decreasing order of significance): advanced age, fewer years of education, female sex, and non-US origin. Fourteen of the inadequately immunized patients were over 70 years of age. Of the 84 patients who reported their immunization histories, five reported no complete series of tetanus shots but had adequate antibody levels, while three reported a complete series but had inadequate levels. Twenty-two patients with inadequate immunity were not offered immunization in the emergency department because they did not have wounds. Patient recall of immunization history is not a reliable guide to tetanus immunization in the emergency department, but patients in certain demographic groups, such as older women, are more likely to have inadequate immunity.