An investigation on the antibody levels to pertussis and diphtheria among healthy people in Wenzhou City / 预防医学

ABSTRACT

Objective To learn the immunity levels of pertussis and diphtheria among healthy people in Wenzhou City,and to provide scientific evidence for the effective control of the two diseases.Methods Stratified sampling method was applied in this investigation and 1 350 healthy people were investigated and provided serum samples.Vaccine immunization of pertussis and diphtheria and demographic characteristics were also collected.Enzyme linked immunosorbent assay (ELISA)was conducted to detect pertussis and diphtheria antibodies.Those with more than 1 00 IU/ml aged more than 3 years were also investigated the disease history.The estimated infection rate of pertussis for population aged more than 3 years was based on the test results.The attenuation trend of pertussis and diphtheria immunity levels after vaccination was analyzed contrastively.Results The antibody positive rate to pertussis was 36. 52%,and the median of antibody concentration was 1 9. 45 IU/m1 .The antibody positive rate and concentration was highest among 36 -60 years old people (64. 29%,36. 39 IU/ml ).The vaccination rate of population with more than 3 doses of DPT (Diphtheria Toxoid -Pertussis Vaccine-Tetanus Toxoid)was 95. 80%,and the corresponding positive rate was 24. 36%.The positive rate was 28. 57% in 0-3 month and 1 0. 71% in 1 0 -1 2 month after vaccination.The antibody concentration to pertussis had a negative correlation with days after vaccination(r=-0. 22,P<0. 05).The proportion of subjects with more than 1 00 IU/ml in population aged more than 3 years was 7. 91%.The estimated infection rate of pertussis for population aged more than 3 years was 49. 27%.The antibody positive rate to diphtheria was 96. 00%,and the median of antibody concentration was 0. 1 3 IU/m1 . The positive rate was highest (1 00%) among 1 -2 years old people and lowest (82. 5%) among newborns.Antibody positive rate (protective rate)and antibody concentration to diphtheria of population which had more doses of DPT or had vaccinated with DT were higher than those had not (P<0. 05 ).The sustainability of vaccine to diphtheria was higher than pertussis after vaccination of DPT.Conclusion Residents in Wenzhou are generally vulnerable to pertussis.Natural infection is considered to be an important influencing factor for the level of pertussis.The level of diphtheria antibodies in Wenzhou is high.The vaccine containing diphtheria is considered useful for children.However,it is suggested to conduct diphtheria booster immunization in older age group.