2007—2011年长沙地区急性下呼吸道感染住院儿童人偏肺病毒的流行状况

Molecular epidemiological and clinical feature of human metapneumovirus in children with acute lower respiratory tract infection in Changsha area from 2007 to 2011

目的了解人偏肺病毒（hMPV）在长沙地区急性下呼吸道感染住院患儿中的流行病学特点。方法收集2007年9月至2011年2月因急性下呼吸道感染在湖南省人民医院儿科医学中心住院儿童的鼻咽抽吸物（nasopharyngealaspirates，NPA）样本2613份，采用逆转录聚合酶链反应法（RT—PCR）检测hMPVM基因，将阳性PCR扩增产物测序并与GenBank中已知的hMPV参考株进行比对、分析。结果2613份标本中hMPV阳性检出数135例，检出率为5．2％，男女之间的检出率比较有统计学差异（x2=8．007，P=0．003），hMPV阳性检出患儿的年龄以1岁以内多见（63．2％）。hMPV阳性检出率在春季呈现高峰，从检出季节分布显示A2b型主要在冬春季节流行，而B2型主要在春夏季流行。135例hMPV长沙株分为A型和B型两个主要的基因型，其中A2b亚型在2007--2008年为优势流行型别，2009--2010年A2b和B2型共同流行，B2亚型在2011年呈优势流行型别。135例hMPV检出阳性患儿中有66例（48．9％）存在混合病毒感染，其中与HBoV混合检出率最高。结论长沙地区部分儿童的急性下呼吸道感染与hMPV有关，且阳性检出患儿年龄主要集中在1岁以下，男多于女，主要流行季节在春季，A2b型和B2型优势基因型在长沙地区共同流行，与其他病毒混合检出率较高。

Objective To understand the epidemiological characteristics of human metapneumovirus （hMPV） infection in children with acute lower respiratory tract infection （ALRTI） in Changsha area, China. Methods A total of 2613 nasopharyngeal aspirate （NPA） specimens were collected from hospitalized children with ARTIs between September 2007 and February 2011 （a period of 3.5 years）in Changsha area,Hunan Province, China. Respiratory specimens were screened for hMPV M gene by reverse-transcription polymerase chain reaction （RT-PCR）. All RT-PCR positive amplification products were confirmed by sequencing or analyzed and compared with those in GenBank known hMPV reference strain. Results hMPV was detected in 135 （5.2%） out of the 2613 children. The detected rate was significantly different between male and female （X2 = 8. 007, P = 0. 003 ）. The majority of the hMPV-positive patients （63.2%） were 0-I year old infants. The majority of hMPV-positive patients were detected during spring season. Seasonal distribution showed that subtype A2b circulated predominantly in winter and spring, subtype B2 circulated predominantly in summer and spring. The most common genotype in 135 hMPV-positive patients were A and B in human subjects in Changsha. The predominant genotype of hMPV changed over the 3.5 year study period from genotype A2b to combined A2b and B2, and to B2.The 66 （48.9%） out of the 135 hMPV-positive patients were found to be co-infected with other respiratory viruses, and human bocavirus （HBoV） was the most common additional respiratory virus. Conclusion These data suggest that some cases of acute lower respiratory infection in young children in Changsha area are related to hMPV and the majority of children infected with hMPV were less than 1 years old, the detected rate of boys was higher than that of girls. It circulated predominantly in spring. The subtype A2b genetic lineage and the subtype B1 genetic lineage of hMPV were revealed ahernately in human subjects in Changsha area and the hMPV exhibited high co-infection rate with other respiratory viruses.