海珠区14岁以下儿童水痘突破病例特征分析

Characteristics of varicella breakthrough cases aged under 14 years in Haizhu District

目的了解广州市海珠区<14岁水痘突破病例特征及疫苗接种对突破病例发生的影响,为完善水痘疫苗免疫策略提供依据。方法通过中国疾病预防控制信息系统和广东省预防接种与疫苗流通管理信息系统分别收集2015—2022年海珠区<14岁水痘病例资料和疫苗接种资料,描述性分析水痘突破病例的发病时间、人群分布特征和疫苗接种情况,采用最小二乘法拟合二元三次函数分析初免月龄、接种间隔对突破间隔的影响。结果2015—2022年海珠区报告<14岁水痘突破病例4008例,占水痘病例总数的29.16%。以1剂突破病例为主,3607例占90.00%。1剂突破病例占病例总数的比例呈下降趋势,2剂突破病例的比例呈上升趋势(均P<0.05)。突破病例发病高峰在3—5月和11月至次年1月,男女比为1.41∶1,发病年龄主要在4~6岁,1189例占29.67%。初免月龄集中在12~<24月龄,2662例占66.42%;2剂接种多在48~<60月龄完成,136例占33.92%。初免在12~<36月龄、接种间隔45个月内的病例突破间隔较长,M(Q_(R))为25.24(20.00)月。初免月龄、接种间隔与突破间隔呈负相关(P<0.05)。结论2015—2022年海珠区<14岁水痘突破病例集中在开学季,高发于学龄前儿童。建议儿童在36月龄内完成第1剂水痘疫苗接种,并在间隔45个月内完成第2剂加强免疫。

Objective To learn the characteristics of varicella breakthrough cases aged under 14 years in Haizhu District,Guangzhou City and the effects of vaccination on incidence of breakthrough cases,so as to provide the basis for improving varicella vaccination strategy.Methods Data of varicella cases aged under 14 years and vaccination in Haizhu District were collected through Chinese Disease Prevention and Control Information System and Guangdong Provincial Vaccination and Vaccine Circulation Management Information System from 2015 to 2022.Temporal distribution,population distribution and vaccination history of varicella breakthrough cases were descriptively analyzed.Effects of primary immunization age and inoculation interval on breakthrough interval were analyzed using least square method fitting bi-cubic functional equation.Results A total of 4008 varicella breakthrough cases aged under 14 years were reported in Haizhu District from 2015 to 2022,accounting for 29.16%of all varicella cases.There were mainly 1-dose breakthrough cases,with 3607 cases accounting for 90.00%.The proportion of 1-dose breakthrough cases showed a downward trend,while the proportion of 2-dose breakthrough cases showed an upward trend(both P<0.05).The epidemics peaked from March to May and from November to January,with a male-to-female ratio of 1.41︰1.The age of onset was mainly at 4 to 6 years,with 1189 cases accounting for 29.67%.The primary immunization age was mainly ranged from 12 to<24 months,with 2662 cases accounting for 66.42%.Vaccination of the second dose was concentrated at the age of 48 to<60 months,with 136 cases accounting for 33.92%.The breakthrough interval was relatively long among cases with primary immunization age at 12 to<36 months and inoculation interval within 45 months,with a median breakthrough interval of 25.24(interquartile range,20.00)months.Primary immunization age and inoculation interval were negatively correlated with breakthrough interval(P<0.05).Conclusions The varicella breakthrough cases aged under 14 years in Haizhu District from 2015 to 2022 were mainly occurred at the beginning of the new term,with a high incidence among preschool children.It is recommended that children receive the first dose of varicella vaccine within 36 months of age and booster within 45 months of interval.