Serological surveillance of antibody levels to pertussis, diphtheria and tetanus among healthy people in Tongchuan, Shaanxi

Objective To understand the immunity levels of pertussis, diphtheria and tetanus among healthy people in Tongchuan,and provide scientific evidence for the effective control of these diseases. Methods Totally 368 healthy people in 7 age groups (1, 1-2, 3-4, 5-6, 7-14, 15-19 and 20 years) were selected in 4 districts in Tongchuan by multi-stage stratified sampling and serum samples were taken from them. Enzyme linked immunosorbent assay (ELISA) was conducted to detect pertussis, diphtheria and tetanus antibodies. Results The antibody positive rate to pertussis was 38.04% with the geometric mean concentration (GMC) of 54.56 U/ml; the antibody positive rate to diphtheria was 94.02%, antibody protective rate to diphtheria was 60.87% with the GMC of 1.61 IU/ml and the antibody protective rate to tetanus was 55.71% with the GMC of 2.70 IU/ml. Conclusion The antibody positive rate to pertussis was low in healthy people in Tongchuan, the antibody protective rate to diphtheria and tetanus were low in healthy people aged 7 years. Outbreaks of diphtheria and neonatal tetanus might not occur recently in Tongchuan, but the potential of pertussis epidemic exist. It is necessary to strengthen the diagnosis of pertussis and timely standardize the case management to prevent the spread of the disease, and it is suggested to conduct diphtheria tetanus booster immunization in older age group.