[Immunity against tetanus in adults over the age of 49 years].

BACKGROUND

Despite the existence of an effective, cheap vaccine with few side effects, tetanus remains present in Spain with most of the cases being observed in subjects over the age of 49 years. The present seroepidemiologic study was performed to detect the degree of protection of this population.

METHODS

The presence of antitetanic antibodies were determined in 324 subjects over the age of 49 (range: 50-88 years, mean 65.5 +/- 9.8 years) in Guipúzcoa. A passive hemagglutination technique (Tetan test; Istituto Sieroterápico Milanese) was used to detect tetanic antitoxoid antibodies following validation of the technique with a neutralizing test of the toxin in white mouse.

RESULTS

Only 12.3% (40/324) of the subjects were considered as immune versus tetanus. The older subjects were the least protected: 7.7% (8/104) of those over 70 years of age versus 17.3% (17/98) of those from 50-59 years of age (chi 2 = 4.34, p = 0.037). The women were globally less protected: 5.4% versus 17% (33/194) males (chi 2 = 9.72; p = 0.002).

CONCLUSIONS

Most of the adult population over the age of 49 years in Guipúzcoa is not protected against tetanus. This is in contrast with the situation observed in the infant and adolescent population. Specific preventive measures directed at the adult and elderly population should be undertaken.