儿童急性呼吸道和消化道脑心肌炎病毒感染的检出和临床流行特征

Prevalence and clinical features of encephalomyocarditis virus infection in children with acute respiratory infection or digestive tract infection

目的调查国内儿童急性呼吸道和消化道感染中是否存在脑心肌炎病毒（EMCV）感染。方法对2013年1月至12月天津市儿童医院收集的577份急性呼吸道感染患儿鼻咽抽吸物和384份消化道感染患儿粪便标本，以针对EMCV5’-UTR基因序列设计的特异性引物进行荧光定量PCR扩增，随机挑选阳性扩增产物进行核苷酸序列测定，并将所测序列在GenBank中进行比对。同时对所有标本进行其他多种呼吸道、消化道相关病毒检测。采用直接免疫荧光测定法检测7种常见呼吸道病毒；金标法检测轮状病毒、腺病毒；酶标法检测星状病毒；PCR方法检测鼻病毒、多瘤病毒wu、多瘤病毒Kl、人博卡病毒、诺如病毒、肠道病毒、Aichi病毒及双埃可病毒；实时荧光定量PCR法检测心病毒。结果577份鼻咽抽吸物标本检测出7例EMCV阳性，阳性率为1．2％。患儿年龄均在6个月以内，检出季节为秋季和冬季；384份粪便标本检测出11例EMCV阳性，阳性率为2．9％。患儿集中在1岁以内及4—7岁，除春季外，其他3个季节均有检出。阳性患儿呼吸道及胃肠道症状以发热、腹泻为主，与其他呼吸道及肠道病毒感染类似。88．9％（16／18例）的患儿居住在郊县和农村。其中5例样本存在与合胞病毒、腺病毒、心病毒和诺如病毒的混合感染。混合感染患儿性别、年龄、住院时间、病情严重程度与单纯EMCV感染患儿相比，均无明显差异。结论中国儿童存在EMCV感染，与呼吸道和消化道感染相关，需进一步检查其他感染是否与EMCV有关。

Objective To investigate the possible existence of encephalomyocarditis virus （EMCV） in chil- dren with acute respiratory infection or digestive tract infection. Methods Nasopharyngeal aspirates from 577 children with acute respiratory infection and fecal samples from 384 children with digestive tract infection in Tianjin Children＇s Hospital were collected from January 2013 to December 2013. Viral nucleic acid was extracted, and EMCV infection was determined by using real - time quantitative PCR. Positive PCR products were sequenced. The sequencing results were aligned with known gene sequences of EMCV sequences in GenBank. Other common respiratory tract or digestive tract viruses were also detected. Direct immunofluorescence was used to detect 7 common respiratory viruses;colloidal gold labeled method was used to detect rotavirus and adenovirus;enzyme linked immunosorbent assay was used to detect avastrovirus ; PCR was used to detect human rhinovirus, WU polyomavirus, KI polyomavirus, human bocavirus, norovi- ruses, enteroviruses, Aichi virus and human pareehovirus. Real - time PCR was used to detect saffold virus. Results Seven（ 1.2% ） nasopharyngeal aspirates from children with acute respiratory infection were positive for EMCV. These children aged 1 -6 months. The infection seasons were in autumn and winter. Eleven（ 2.9%v ） fecal samples from chil- dren with digestive tract infection were positive for EMCV. Positive specimens were in patients less than 1 year of age and 4 - 7 years of age. EMCV was identified in other 3 seasons except spring. The clinical diagnosis of the EMCV - po- sitive patients were fever or diarr-hea, which was similar with other respiratory tract or digestive tract viruses. There were 88.9% （ 16/18 cases） of these EMCV infected children lived in suburbs or countryside. There were a few co - infec- tions with EMCV and other respiratory tract or digestive tract viruses. There was no obvious difference in the clinical symptoms between EMCV - positive patients with or without coinfection. Conclusions Infection of EMCV often occurs in children with acute respiratory infection or digestive tract infection in China. Some of acute respiratory infection or digestive tract infection in pediatric patients was related to EMCV.