The purpose was to discuss the infection status of human parainfluenza virus type 3 (HPIV-3) in children with acute respiratory tract infection(ARTI) in Qingdao, Shandong province, and to analyze the gene characteristics of HPIV-3 hemagglutinin-neuraminidase protein (HN). This study was a cross-sectional study. A total of 1 674 throat swab samples were collected randomly from children with ARTI, in the three hospitals (Qingdao Women and Children's Hospital, West Coast Branch of Affiliated Hospital of Qingdao University, Laoshan Branch of Affiliated Hospital of Qingdao University) from January 2018 to December 2019. Multiplex real-time fluorescence RT-PCR was performed to screen HPIV-3 positive specimens. For HPIV-3 positive specimens, nested PCR was used to amplify the full-length HN gene of HPIV-3. The HN gene was sequenced and compared with the representative strains of HPIV-3 in GenBank, and the phylogenetic tree was established. As results, this study collected 1 674 samples, in which there were 90 HPIV-3 positive samples showed and the detection rate was 5.37%. Among positive specimens, the number of samples from children under 6 years old was 88, accounting for 97.78%. HPIV-3 positive cases were mainly distributed in spring and summer. The full-length sequences of 44 HPIV-3 HN genes were obtained by nested PCR method. Sequence alignment and evolutionary analysis showed that the HPIV-3HN gene belonged to the C3a and C3b branches of C3 genotype, with 30 strains of subtype C3a and 14 strains of subtype C3b. The nucleotide and amino acid homology of the amplified 44 strains of the HPIV-3 HN gene in Qingdao were 97.0%-100.0% and 98.5%-100.0%, respectively. In conclusion, from 2018 to 2019, the C3a and C3b branches of HPIV-3 C3 genotype were circulating prevalent in Qingdao, Shandong province. HN gene variation rate was low, but showed certain regional characteristics in evolution.
探讨山东省青岛市地区急性呼吸道感染患儿人副流感病毒3型（HPIV-3）的感染情况，并分析HPIV-3血凝素-神经氨酸酶蛋白（HN）基因特征。本研究为横断面研究，青岛市妇女儿童医院、青岛大学附属医院西海岸院区及崂山院区在2018年1月至2019 年12月期间，每月随机采集急性呼吸道感染（ARTI）儿科患者的咽拭子样本，总共1 674份，采用多重实时荧光逆转录-聚合酶链反应（RT-PCR）方法，筛查HPIV-3阳性样本。采用巢式PCR方法扩增HPIV-3阳性样本HN全长基因并进行序列测定，序列结果与GenBank中HPIV-3的代表株进行对比分析，建立系统进化树。结果显示，1 674份咽拭子样本中，HPIV-3阳性有90份，检出率为5.37%，其中，6岁以下儿童占97.78%（88份）。HPIV-3阳性病例主要分布在春季和夏季。通过巢式PCR方法扩增得到44株HPIV-3 HN基因全长序列，序列比对及进化分析表明，HPIV-3 HN基因属于C3基因亚型的C3a和C3b分支，其中，C3a亚型有30株，C3b亚型有14株。44株青岛分离株之间的核苷酸和氨基酸同源性分别为97.0%~100.0%和98.5%~100.0%。综上，2018至2019年间，HPIV-3 C3基因型的C3a和C3b分支在山东省青岛市地区循环流行，其HN基因型变异较小，进化上具有一定的地域特征。.