Viral infection and epidemiological characteristics of human metapneumovirus in febrile respiratory syndrome cases in nine provinces in China from 2009 to 2021 / 中华实用儿科临床杂志

Objective:To clarify the infection and epidemic characteristics of the human metapneumovirus (HMPV) in Chinese patients with febrile respiratory syndrome (FRS), and to provide important baseline data for clinical diagnosis, treatment, prevention and control of HMPV-induced respiratory tract diseases in China.Methods:FRS cases from January 2009 to June 2021 in 9 provinces in China, including Beijing, Hebei, Jilin, Shandong, Shaanxi, Xinjiang, Anhui, Guangdong, Hunan were retrospectively analyzed for their respiratory samples, clinical and epidemic data.The respiratory samples were detected for HMPV by quantitative real-time PCR.Results:A total of 11 660 cases were tested for HMPV, involving 296 (2.54%) HMPV-positive cases.Among 296 HMPV-positive cases, 218 were single HMPV infection, and 78/296 (26.35%) were co-infected with one or more respiratory viruses.HMPV mainly affected children under 5 years of age (3.10%), and in this population, the proportion of pneumonia in HMPV co-infection cases was significantly higher than that of single HMPV infection.HMPV could be detected all year round, which was more popular in winter and spring, with the peak of HMPV epidemic in March.Conclusions:HMPV is one of the important pathogens causing acute respiratory infection in children, showing a clear seasonal epidemic.HMPV can be infected alone or in combination with other respiratory viruses, which may increase the risk of pneumonia in children.

Viral etiology of acute upper respiratory infection in Hebei Province from 2013 to 2015 / 中华疾病控制杂志

Objective To investigate the viral etiology and the epidemilogy of acute upper respiratory tract infection in Hebei Province from 2013 to 2015,providing scientific basis for diagnosis,prevention and control of the respiratory tract infection.Methods l 551 throat swab samples of the acute upper respiratory infection patients from four hospitals in Hebei Province were collected,Multiplex real-time PCR was used to detect 15 kinds of respiratory tract viruses for all specimens after nucleic acids extraction.Results Totally 714 positive samples were obtained from 1 551 samples,with a positive rate of 46.03％.Human rhinovirus(186,11.99％)was detected as the most common viral species,followed by human parainfluenza 3(167,10.77％),respiratory syncytial virus (122,7.87％),adenovirus (108,6.96％),influenza B virus (56,3.61％),human metapneumovirus(40,2.58％),influenza A virus(39,2.51％),human boca virus (38,2.45％),human parainfluenza 1 (35,2.26％),human coronavirus-229E/NL63 (33,2.13％),human enterovirus (32,2.06％),human parainfluenza 4(31,2.00％),human coronavirus-OC43 (30,1.93％),and human parainfluenza 2(11,0.71％).176 cases (11.35％) were detected as co-infection.The infection rate(56.07％) of under 5 years old group was higher than that of other groups.Conclusions The predominant respiratory viruses,who are responsible for acute upper respiratory tract infections in Hebei Province,are HRV,PIV3,RSV,ADV and IFV.Each virus possess the specific epidemiological feature.

Evolutionary characterization of HA1 gene of influenza A H3N2 viruses from 2003 to 2008 in Hebei / 中华疾病控制杂志

Objective To understand the genetic characterization of HA1 gene of influenza A H3N2 viruses circulated in recent years in Hebei.Methods Viral RNAs of 25 H3N2 strains were extracted and amplified by Reverse Transcription Polymerase Chain Reaction (RT-PCR).The products of PCR were purified and sequenced,and the sequences were analyzed though biometic software.Results Several amino acid substitutions located in antigenic sites or receptor binding sites were found more in the isolates than the current vaccine virus or the isolates from previous year.Amino acid substitution was found in 3,140,142,144,145,158,159,189,192,193,198,204,225,226 and 227 positions in the isolates during 2003-2008,more amino acid substitutions took place in antigenic determinant A,B and receptor binding site (RBS).New phylogenetic branches appeared continuously during 2003-2008.The H3N2 strains of the same year almost clustered in the same group on the phylogenetic tree.Conclusions Amino acid substitutions continuously occurred in the HA1 genes in influenza A H3N2 viruses isolated in Hebei from 2003 to 2008,it is meaningful to pay close attention to the HA1 variation in order to prevent and control influenza.

Virological surveillance and variability of influenza viruses in Hebei,2005～2006 / 中华疾病控制杂志

N)compared with B/HongKong/330/2001.Conclusions H1,H3 and B virus were circulated in Hebei from 2005 to 2006.Recent viruses were changing in genetic characteristics,while influenza B viruses varied more obviously.