南京市0～8岁儿童巨细胞病毒感染流行病学调查

Seroprevalence of Cytomegalovirus infection in children aged 0-8 years in Nanjing

目的调查儿童巨细胞病毒（CMV）感染率及首次感染的年龄，为了解中国CMV感染现状提供循证医学证据。方法随机抽取2011年6月至9月在南京市儿童医院体检的837例儿童。男513例，女324例；年龄1d～8岁，平均3．6岁。采用固相ELISA酶联免疫试剂，定性检测体检儿童血清中CM IgM抗体、定量检测CMVIgG抗体浓度及IgG亲合力指数。结果837例儿童血清中，CMV IgG阳性690例，阳性率为82．4％。其中男童阳性427例，阳性率83．2％；女童阳性263例，阳性率81．2％，男童与女童CMV IgG阳性率之间差异无统计学意义（X2=0．584，P=0．445）。在92例6月龄以内的儿童中，其中86例CMVIgG阳性，阳性率为93．5％；7月龄之后阳性率逐渐下降，在9月龄下降至最低，为66．7％，然后随年龄增长而升至80．O％左右（X2=15．4，P〈0．001）。从837例儿童中按年龄段随机抽取352例，同时检测其血清CMV IgM，共23例阳性，总IgM阳性率为6．5％，其中以2～3月龄婴儿阳性率最高，达58．3％，之后逐渐下降，6岁以后未检出CMV IgM阳性病例（X2=5．1，P〈0．001）。进一步检测23例活动性感染标本的IgG抗体亲合力指数，发现13例IgG亲合力指数〈30％，原发感染率为56．5％，其中以〈1岁儿童居多（7例），占总原发感染数的53．8％。结论目前南京地区儿童CMV感染率大约为80．0％，低于成人，其首次感染多数发生在3月龄前。

Objective To investigate the seroprevalence of Cytomegalovirus （CMV） infection and ages of the children in primary for better understanding the status of CMV infection in China with evidence-based medicine. Methods Total 837 children randomly selected from Nanjing Children＇s Hospital,from Jun. to Sep. in 2011 ,including 513 boys and 324 girls,aged from 1 day to 8 years,with mean age of 3.6 years old ,were recruited. Serum samples were tested for CMV IgM, CMV IgG, and CMV IgG avidity index using commercial enzyme-linked immunosorbent assay kits. Results Of the total serum samples from 837 children,690 cases were CMV IgG positive. The overall seroprevalence of CMV IgG was 82.4% ,with 83.2% （427/513 cases） and 81.2% （263/324 cases） in boys and girls,respectively. There was no significant difference in the seroprevalence of CMV IgG between boys and girls （X2 = 0. 584, P = 0.445 ）. Of the 92 infants less than 6 months old,86 cases were CMV IgG positive, and the positive rate was 93.5 %. The prevalence gradually declined in infants after 7 months old, fell to the lowest level of 66.7% at age of 9 months, and then constantly maintained around 80.0% from 1 to 8 years old （X2 = 15.4 ,P 〈 0. 001 ）. CMV IgM in 352 serum samples were tested,and 23 （6.5%） cases were CMV IgM positive. The positive rate peaked in infants at age of 2 -3 months （7/12 cases ,58.3% ） ,then decreased over the age and none of the children older than 6 years were IgM positive （X2 = 5.1 ,P 〈0.001 ）. Furthermore,the CMV IgG avidity index assay was performed in all 23 cases of IgM positive individuals to estimate the primary CMV infection rate. The results showed low avidity index （ 〈 30% ） in 13 infants ,the primary infection rate was 56.5% （13/23 cases）. Most subjects with primary infection （n = 7,53.8% ） were younger than 1 year old. Conclusions The current seroprevalence of CMV IgG in children in China was around 80.0% ,lower than that in adults, and the primary CMV infection mostly occurred before 3 months of age.