Indexed on: 18 Jun '03Published on: 18 Jun '03Published in: Swiss medical weekly
In the industrialised world, the elderly carry the highest risk for tetanus. This prospective serological study was performed to evaluate the reliability of tetanus immunisation histories and the antibody response to tetanus vaccinations in the elderly.40 individuals >65 years with a bleeding trauma were included in the study. Their tetanus vaccination histories were investigated, and accordingly a single booster (group A, n = 7), or a three dose basic immunisation against tetanus (group B, n = 33) was provided. In addition, tetanus antitoxin levels were determined.Age varied between 67 and 95 years. Inconsistencies regarding the vaccination history were found between patients and their physicians in 30% (12/40), between patient statements and vaccination documents in 57.1% (8/14) and between physicians' records and vaccination documents in 35.7% (5/14). Antitoxin titres >0.15 IU/ ml were considered protective, giving a seroprevalence of 92.5%. Sensitivities and negative predictive values for tetanus immunity were 30.6% and 10.7% based on patient histories and 2.8% and 7.9% based on physicians' records. In group A, after the single booster immunisation the median titre rose from 1.2 to 14.2 IU/ml, in group B from 0.9 to 5.3 IU/ml after the first, and to 9.6 IU/ml after the third tetanus toxoid dose (p <0.001 using Friedman's test).In Switzerland, elderly patients with a tetanus prone wound provide an unreliable vaccination history but their seroprotection against tetanus is high. A single booster for secondary immunisation is therefore sufficient. It is not necessary to take the largely unreliable vaccination history into account.