Sero-epidemiological study and infection rate evaluation of pertussis in Henan Province
Objective To analyze the epidemiological distribution characteristics,influencing factors,and infection rates of pertussis in the population of Henan Province.Methods From 2022 to 2023,a cross-sectional survey was conducted to investigate the permanent population in Henan Province.Enzyme-linked immunosorbent assay(ELISA)was used to detect anti-pertussis toxin IgG(PT-IgG),analyze the antibody positivity rate(≥20 IU/ml)and median concentration(MC),and estimate the pertussis infection rate based on PT IgG ≥40 IU/ml.The rank sum test was used to compare antibody levels among groups,and the x2 test was used to compare antibody positive rates and infection rates among groups.Results A total of 4 810 research subjects were included in this study.The overall positive rate of PT-IgG was 12.10％and MC was 3.04(0.35,10.36)IU/ml.There were significant differences both in positive rates and antibody levels of PT-IgG among different regions or age groups(region positive rate:x2=134.06,P＜0.001,MC:H=337.74,P＜0.001;age group positive rate:x2=45.27,P＜0.001,MC:H=134.49,P＜0.001).Both the positive rate of PT-IgG(25.26％)and MC(8.01 IU/ml)were the highest within one year after completing a full course of vaccination.There were significant differences in positive rates and antibody levels among people receiving different types of pertussis vaccines(positive rate:x2=12.38,P=0.006,MC:H=17.93,P＜0.001).The antibody positivity rate(35.71％)and MC(8.88 IU/ml)of the people who received cell-free pertussis inactivated poliomyelitis influenza type b(combined)vaccine throughout the course were higher than those who received other types of vaccines.The natural infection rate of pertussis was evaluated for individuals aged≥3 years who had no history of pertussis vaccine immunization within the year prior to sampling.With a high vaccination rate,the estimated infection rate of pertussis in the population was 5 757.22/100 000.The infection rates in the 3-year-old(1 940.16/100 000)and 4-year-old(1 765.68/100 000)populations were at a low level among the entire population,reaching their peak at the age of 6(12 656.71/100 000).Subsequently,although the infection rate continued to decline,it remained at a high level and peaked again at the age of 40-49 years(8 740.39/100 000).There was a statistically significant difference in the estimated infection rate of pertussis among different age groups(x2=53.21,P＜0.001).Conclusion The PT-IgG level of pertussis in the population of Henan Province is generally at a low level.The estimated infection rate of pertussis is much higher than the reported incidence rate.A booster dose of pertussis vaccine is recommended at 6 years old.
万方数据
维普
