目的:百日咳的复发已在世界各地发生。然而,目前的疾病监测无法很好地了解百日咳的流行病学特征.本研究旨在了解湖州市普通人群百日咳感染的血清流行病学特征,评估百日咳在人群中的感染率,并提供见解,以指导百日咳预防和控制策略的调整。
方法:2023年9月至10月,在湖州市进行了横断面血清调查,涉及1015名永久居民。从研究对象中收集血清样本,采用酶联免疫吸附试验(ELISA)定量检测百日咳毒素IgG抗体(抗PT-IgG)。分析包括抗PT-IgG的几何平均浓度(GMC),GMC≥40IU/mL,≥100IU/mL,和<5IU/mL。根据年龄进行分层比较,疫苗接种史,和人类类别。
结果:在1015名接受调查的个人中,抗PT-IgG的几何平均浓度(GMC)为10.52(95%CI:9.96-11.11)IU/mL,最近的感染率为1.58%,血清阳性率为11.43%,<5IU/mL的比例为40.49%。在357名有明确疫苗接种史的儿童中,易感性随着疫苗剂量的增加而降低(Z=-6.793,P<0.001)。抗PT-IgG的浓度随时间显示出显著的接种后下降(Z=-5.143,P<0.001)。在育龄妇女中,抗PT-IgG的GMC为7.71(95%CI:6.90-8.62)IU/mL,不同年龄组易感性差异无统计学意义(χ2=0.545,P=0.909)。年龄≥3岁个体的百日咳年感染率为9321(95CI:3336-16039)/100,000,其中20-29、40-49和5-9年龄组的峰值感染率分别为34363(95CI:6327-66918)/100,000,22307.72(95CI:1380-47442)和18020(95CI:1093-37100,000266)。
结论:2023年,湖州市人群实际百日咳感染率较高。疫苗诱导的抗体表现出快速衰减,估计的血清感染率从学后开始迅速增加,在20-29岁年龄段达到顶峰。建议加强青少年和成人百日咳监测,并完善疫苗免疫策略。
OBJECTIVE: The resurgence of pertussis has occurred around the world. However, the epidemiological profiles of pertussis cannot be well understood by current diseases surveillance. This study was designed to understand the seroepidemiological characteristics of pertussis infection in the general population of Huzhou City, evaluate the prevalence infection of pertussis in the population, and offer insights to inform adjustments in pertussis prevention and control strategies.
METHODS: From September to October 2023, a cross-sectional serosurvey was conducted in Huzhou City, involving 1015 permanent residents. Serum samples were collected from the study subjects, and pertussis toxin IgG antibodies (Anti-PT-IgG) were quantitatively measured using enzyme-linked immunosorbent assay (ELISA). The analysis included the geometric mean concentration (GMC) of Anti-PT-IgG, rates of GMC≥40IU/mL, ≥100IU/mL, and <5IU/mL. Stratified comparisons were made based on age, vaccination history, and human categories.
RESULTS: Among the 1015 surveyed individuals, the geometric mean concentration (GMC) of Anti-PT-IgG was 10.52 (95% CI: 9.96-11.11) IU/mL, with a recent infection rate of 1.58%, a serum positivity rate of 11.43%, and a proportion with <5IU/mL of 40.49%. Among 357 children with clear vaccination history, susceptibility decreased with an increasing number of vaccine doses (Z = -6.793, P < 0.001). The concentration of Anti-PT-IgG exhibited a significant post-vaccination decline over time (Z = -5.143, P < 0.001). In women of childbearing age, the GMC of Anti-PT-IgG was 7.71 (95% CI: 6.90-8.62) IU/mL, with no significant difference in susceptibility among different age groups (χ2 = 0.545, P = 0.909). The annual pertussis infection rate in individuals aged ≥3 years was 9321 (95%CI: 3336-16039) per 100,000, with peak infection rates in the 20-29, 40-49, and 5-9 age groups at 34363 (95%CI: 6327-66918) per 100,000, 22307.72 (95%CI: 1380-47442) per 100,000, and 18020(95%CI: 1093-37266) per 100,000, respectively.
CONCLUSIONS: In 2023, the actual pertussis infection rate in the population of Huzhou City was relatively high. Vaccine-induced antibodies exhibit a rapid decay, and the estimated serum infection rate increases rapidly from post-school age, peaking in the 20-29 age group. It is recommended to enhance pertussis monitoring in adolescents and adults and refine vaccine immunization strategies.