[Analysis of diphtheria antibody levels in healthy population in Beijing municipal, 2007].

Objective: To investigate the diphtheria antibody level in healthy population in Beijing.

Methods: 10 age groups (< 1, 1 to 4, 5 to 9, 10 to 14, 15 to 19, 20 to 24, 25 to 29, 30 to 34, 35 to 39, and > or =40) were sampled by the Multi-stage stratified sampling method in 9 districts in Beijing, and 2 003 sera from healthy population were collected. The diphtheria antibody was determined with ELISA method.

Results: The diphtheria antibody-positive rate was 60.26%, and the antibody concentration was 0.62 IU/ml. A trend of decreasing in the antibody concentration was observed with increasing age and years after immunization. Antibody levels were the lowest in healthy people between 25-40 years old.

Conclusion: It was predicted that a large scale of diphtheria outbreak would not occur recently in Beijing. It is recommended that for all adults diphtheria toxoids booster immunization should be conducted every 10 years for all adults.