[Antidiphtheria immunity of the Algerian population: a seroepidemiological study]

The antidiphtheria immunity of the Algerian population is not well known. Thus, a study was carried out on 1755 blood samples, in 1998 to better assess this vaccinal status. Three epidemics occurred in Algeria, in the years 1993, 1994, 1995, and then immunization sensitizing campaigns were introduced in September 1995.

The procedure that was used was based on the immunoenzymatic method, the reagents of which were ready for use. The interpretation of our results and vaccinal policy deduction were performed according to the VIROTECH Diphtheria ELISA technique which offers five classes in antitoxin titers: I. <0.1 IU/ml basic immunization immediately. II. 0.1-1.0 IU/ml booster immunization immediately. III. 1.0-1.4 IU/ml booster vaccination 5 years later. IV. 1.5-2.0 IU/ml booster vaccination 7 years later. V. >2.0 IU/ml booster vaccination 10 years later.

In our series, 17.03% of the samples had a titer <0.1 IU/ml considered as insufficiently protective, an immunization was therefore recommended. 59.82% had titers ranging between 0.1 and 1 IU/ml, 5.98% had titers ranging between 1 and 1.4 IU/ml, 3.36% had titers ranging between 1.5 and 2 IU/ml, and 13.79% had titers >2 IU/ml.