儿童严重急性呼吸综合征血清流行病学特征初探

A preliminary investigation on the serological and epidemiological characteristics of severe acute respiratory syndrome in children

目的 了解儿童严重急性呼吸综合征 (SARS)患者SARS相关冠状病毒 (SARS CoV)特异抗体水平 ;初步调查与成人SARS患者密切接触的儿童 /成人及与SARS患儿密切接触的家长中隐性感染的情况。方法 (1)采用间接免疫荧光 (IFA)和ELISA两种方法 ,对北京市恢复期儿童SARS患者 2 1例、与其密切接触的家长 2 3位、与SARS成人患者密切接触的儿童 2 4名和成人 34名 ,分别进行了SARS CoV特异抗体的检测 ,其中IFA检测IgG抗体 ,ELISA检测混合抗体。 (2 )通过入户问卷收集流行病学资料。结果 (1)IFA测定SARS患儿血清SARS CoV IgG阳性者 8例 (38% ) ,同时经ELISA法测定SARS CoV混合抗体阳性者 7例 (33% )。 (2 )有SARS接触史的患儿在抗体阳性组中为 7/8,而在抗体阴性组中为 1/13。 (3)SARS患儿的家长中一位 (患儿的祖母 )经IFA检测SARS CoV IgG和ELISA法检测混合抗体为阳性 (1/2 3,4 % ) ,该患儿的祖父为SARS患者。 (4)对成人SARS患者的密切接触儿童调查结果为 :2 4份受检标本中 1份SARS CoV IgG阳性 (4% ) ;34份受检成人标本中 1份经IFA检测SARS CoV IgG和ELISA法检测混合抗体均为阳性 (3% )。 结论(1)临床诊断的儿童SARS患儿中有 38%经血清学证实为SARS CoV感染。(2 )流行病学资料显示 。

Objective The severe acute re spiratory syndrome (SARS) is a highly contagious infection caused by a newly dis covered strain of coronavirus (SARS-CoV). During the outbreak of SARS in the fi rst half of 2003, children appeared to be less susceptible to the SARS coronavir us and pediatric patients presented with a less aggressive clinical course than adult patients did, demonstrating the traits which were rarely observed in other viral contagious disease. The present study aimed to preliminarily examine the presence of serum specific antibodies against severe acute respiratory syndrome (SARS) -associated coronavirus virus (SARS-CoV) in pediatric SARS patients and explore the possibility of subclinical infection in children/adults through clo se association with SARS cases. Methods (1) Clinicians an d nurses visited families and collected general and epidemiological information about the subjects using a standard questionnaire and took serum specimens. (2) Specific antibodies against SARS-CoV were assayed with two methods, indirect i mmunnofluorescence assay (IFA) for detecting IgG antibodies and enzyme linked im munosorbent assay (ELISA) for mixed antibodies. Serum specimens tested included those from 21 clinically confirmed pediatric SARS cases (aged from 8 months to 14 years, 11 male and 10 female) and their 23 parents who had close contact with the children, 36 adult patients in convalescence stage of SARS , 24 children (a ged 1.5 to 14 years) and other 34 adults who had close contact with infected adu lts. Results (1) The positive rates of specific IgG and mixed antibodies against SARS-Co V were 38% (8/21) and 33%(7/21) in pediatric cases; whereas the rates were 75% ( 27/36) and 69% (25/36) in adult patients. (2) The proportion of the patients who had close contact to SARS patients was 7/8 among the antibody-positive group v s. 1/13 for the antibody-negative group (P<0.05). (3) The IgG antibody emer ged in one of 24 children, whose morther, a nurse, had suffered from SARS (4%). (4) Among 23 parents of children with SARS, one was positive for IgG and the mix ed antibodies, whose grandson and husband suffered from SARS; The IgG antibody a nd the mixed antibodies were also positive in another adult who had close contac t with adult SARS cases (3%). Conclusions (1) SARS-CoV i nfection was confirmed by serological methods in 38.1% of clinically diagnosed p ediatric SARS cases, which leads to the assumption that correct diagnosis of ped iatric SARS requires more accurate and efficient ways, for example, screening fo r antigen or gene of SARS-CoV. (2) The proportion of the patients who had close contact to SARS patients among antibody-positive cases was higher than that in antibody-negative cases. (3) It is possible that subclinical SARS CoV infectio n exists in children and adults, although the rate of occurrence is low. The dat a of the present study did not confirm that SARS had subclinical infection among adults who had close contact to pediatric SARS cases.