SEROLOGICAL SURVEY ON THE IMMUNITY TO DIPHTHERIA OF THE NORTHERN GREEK POPULATION

The recent outbreak of diphtheria in the Newly Independent States (NIS ) of the former USSR and the immigration from these high risk areas to Greece prompted us to determine the diphtheria antitoxin levels by en zyme-linked immunosorbent assays (ELISA) in 509 healthy individuals (3 07 males and 202 females) from northern Greece. The population under s tudy was divided in ten age groups from 1 day to > 60 years old. Dipht heria antitoxin levels of greater than or equal to 0.1 IU/ml were cons idered as protective ones. 44.6% of the examined people were found sus ceptible. The children up to their twenties seem to be immune to dipht heria in a high proportion (86-88.4%). The diphtheria antitoxin levels declined sharply above this age (17.6% in the age group 21-30 years o ld). The level of protection in adults appeared to be higher in the ol dest group (49%). According to these results, the adults are not prope rly protected. Booster doses of vaccine for them are recommended to im prove the resistance of the northern Greek population from possible in fection by toxigenic stains of Corynebacterium diphtheriae, imported o r endogenous.