Department of Disease Control Policy, Gyeonggi Provincial Government, Suwon, Korea.
Central Disease Control Headquarters, Korea Disease Control and Prevention Agency, Cheongu, Korea.
Epidemiol Health. 2021;43:e2021053. doi: 10.4178/epih.e2021053. Epub 2021 Aug 18.
Pertussis or whooping cough-one of the most contagious diseases-is caused by the Gram-negative bacterium Bordetella pertussis. Despite a high vaccination rate, Korea recently experienced a resurgence of pertussis. This study explores patterns and possible explanations for this resurgence through an age-period-cohort analysis.
Using secondary data from the infectious disease portal of the Korea Disease Control and Prevention Agency and the Korea Statistical Information Service of Statistics Korea, this study analyzed the incidence of pertussis in Korea to determine which factors contributed to the recent increase using an age-period-cohort model.
Analysis of the age effect indicated that the age group most vulnerable to pertussis was 0-year to 2-year-olds. Analysis of the period effect showed a sharp increase in the incidence rate after 2016. Analysis of the cohort effect showed a significant decrease in incidence beginning with the 1955 birth cohort, with the risk increasing again with the 2000s birth cohort.
Previous studies have suggested 3 main possible explanations for our results. First, the increased incidence rate can be attributed to contact rates. Second, the rate of immunity through natural exposure has decreased due to the low number of circulating pathogens, in turn affecting the trend of infection. Lastly, variations in pathogens may have also contributed to the increase in incidence. Given that the most significant increase in incidence was observed among infants younger than 1 year old, sufficient maternal immunity must be prioritized to provide passive immunity to newborns via the placenta.
百日咳（俗称“鸡咳”“鸬鹚咳”）是由革兰氏阴性细菌百日咳博德特氏菌引起的最具传染性的疾病之一。尽管接种率很高，但韩国最近百日咳疫情有所反弹。本研究通过年龄-时期-队列分析探讨了这种反弹的模式和可能的解释。
本研究利用韩国疾病控制与预防机构传染病门户和韩国统计信息服务部的二级数据，分析了韩国百日咳的发病率，以确定年龄-时期-队列模型中哪些因素导致了最近的发病率增加。
年龄效应分析表明，最易感染百日咳的年龄组为 0 岁至 2 岁。时期效应分析显示，2016 年后发病率急剧上升。队列效应分析显示，1955 年出生队列的发病率开始显著下降，2000 年出生队列的发病率再次上升，风险增加。
之前的研究提出了我们的研究结果的 3 个可能的主要解释。首先，发病率的增加可以归因于接触率的增加。其次，由于循环病原体数量减少，自然暴露产生的免疫力降低，进而影响了感染趋势。最后，病原体的变异也可能导致发病率的增加。鉴于发病率的显著增加发生在 1 岁以下的婴儿中，必须优先考虑母体免疫力，通过胎盘为新生儿提供被动免疫力。
