Recent increase of pertussis in South Korea: age-period-cohort analysis

pertussis;whooping cough;DTaP;immunization;vaccination;age-period-cohort analysis;apc;intrinsic estimator;614

보건대학원 보건학과(보건학전공) ;

University:서울대학교 대학원

关键词: pertussis;    whooping cough;    DTaP;    immunization;    vaccination;    age-period-cohort analysis;    apc;    intrinsic estimator;    614;   

Others  :  http://s-space.snu.ac.kr/bitstream/10371/161291/1/000000156838.pdf

美国|英语

来源: Seoul National University Open Repository

【 摘 要 】

Pertussis is one of the most contagious disease, which is caused by a gram-negative bacterium called Bordetella pertussis. Pertussis is preventable by vaccination. Routine vaccination schedule of DTaP vaccine consists of 5-dose series at 2, 4, 6, 15-18 month and 4-6 years old. Despite the significant improvement in vaccination coverage, pertussis still attributes morbidity and mortality, particularly of infants and young. Resurgence of pertussis has been reported since 1980s in the developed countries, despite of their high vaccination coverage. After substantial decrease of pertussis by introduction of universal vaccination, South Korea also has experience resurgence of pertussis since 2000s. Many researches have tried to figure out the reason of pertussis resurgence. So far, few studies have addressed the cohort effect on the recent increase of pertussis. This study expects to figure out the specific birth cohorts who experienced the combined effects of various factors.With secondary data from Infectious Disease Portal of Korea Center for Disease Prevention & Control and Korea Statistical Information Service of Statistics Korea, this study analyzed the incidence of pertussis in South Korea to figure out the factors contribute to the recent phenomena using age-period-cohort model.Age effects indicates that the most vulnerable age group to pertussis is 0-2 years old group. After the sharp decrease at 3-5 years old group, the risk arises again until 9-11 years old, and then the decrease again 54-56 years old. After the lowest point at 54-56 years old, risk increases again. The period effect shows sharp increase after 2016. With cohort effect, significant decrease is observed from the introduction beginning at 1955 birth cohorts. However, since 2000s birth cohorts, the risk has started to rise again.To explain the result of age effect, effectiveness of vaccination and age-specific social contact rates are suggested from previous studies. For period effect, following explanations are suggested from previous studies: antigenic variation, decreased opportunity of natural boosting due to lowered number of circulating pathogens, elated recognition and reporting, and improvement of diagnostic tools. For cohort effect, this research suggested decreased maternal immunity as a factor that contributed to recent increase of pertussis in South Korea. Recent phenomenon is resulted from lack of passive immunity from maternal body due to waning immunity after vaccination combined with decreased opportunity of natural boosting.From a view of public health, providing additional chance of boosting is available intervention. Considering the most significant increase of incidence rate occurred within infant aged under 1 year old, it is important to establish enough maternal immunity to provide passive immunity via placenta for babies.