ABSTRACT
Objective To establish real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) for human coronaviruses(HCoV)-NL63,HCoV-HKU1,HCoV-OC43 and HCoV-229E,and to investigate the prevalence of the four coronaviruses in children with acute respiratory tract infection(ARTI) in Fuzhou area.Methods Totally of 538 nasopharyngeal swabs were collected from pediatric patients with ARTI,including 289 specimens from children with acute upper respiratory tract infection (AURTI) and 249 from acute lower respiratory tract infection (AURTI) during three consecutive winter-spring seasons from December to April of 2006 - 2009 in Fuzhou area.All the specimens were subjected to FQ-PCR specific for HCoV-NL63,HCoV-HKU1,HCoV-OC43 and HCoV-229E,respectively.The enumeration data were analyzed by chi square test.Results The FQ-PCR methods were established for detecting HCoV-NL63,HCoV-HKU1,HCoV-OCA3 and HCoV-229E.The intraassay coefficient of variation (CV) and interassay CV were both ≤ 1.6％.The coronaviruses were detected in 41 (7.6％) children with ARTI,including HCoV-NL63 in 8 (1.5％)children (1 with AURTI,7 with ALRTI),HCoV-229E in 5 (0.9％; 1 with AURTI,4 with ALRTI),HCoV-HKU1 in 6 (1.1％; 1 with AURTI,5 with ALRTI),and HCoV-OC43 in 22(4.1％; 13 with AURTI,9 with ALRTI).The four coronaviruses were detected during each of the three winter-spring seasons and the positive rates of different periods were not significantly different (P＞0.05).The HCoV-OC43 positive rate was significantly higher than HCoV-NL63,HCoV-229E and HCoV-HKU1 (x2 =6.721,10.979,9.387; respectively; all P＜0.01).ConclusionsIt is suggested that the four coronaviruses might be important virus pathogens in children with ARTI in Fuzhou,China.And detection of them is needed for etiology and epidemiology evaluations for children with ARTI.
ABSTRACT
Objective To investigate the prevalence of human metapneumovirus (HMPV)infection in patients with respiratory infection in Fuzhou area and compare their epidemic features and clinical characteristics with those of infected with respiratory syncytial virus (RSV). Methods A total of 153 sputum or pharyngeal swab samples from patients with respiratory tract infection were collected in Fujian Provincial Hospital in consecutive winter and spring seasons from 2005 to 2007. HMPV was detected by nested reverse transcriptase-polymerase chain reaction (RT-PCR) and RSV was tested by RT-PCR. Parts of PCR products were sequenced and analyzed using DNAMAN software. The clinical symptoms, signs and epidemiology of the respiratory tract infections caused by HMPV and RSV were compared. Results In the 153 specimens, 32 (20.9%) were positive for H MPV, 26 (17.0%) were positive for RSV, and 8 were both HMPV and RSV positive. Nucleotide sequences of three 432-bp PCR products were 100% identical and submitted to GenBank (the accession No. DQ887758).Phylogenetic tree analysis of nucleotide sequences revealed that the three isolates clustered in HMPV belonged to genotype A with part of mutation. Twenty-six samples (26. 7%) were HMPV positive from Dec 2005 to Apr 2006 and 6 (10.7%) were positive from Dec 2006 to Apr 2007. The RSV detection rate was opposite of HMPV. The mean age of RSV infection in children was (2.65±2.65)years old and HMPV infection was (4.58 ±3.35) years old. The main clinical manifestations of both RSV and HMPV infections were cough, sore throat and fever. Conclusions Both HMPV and RSV are the major pathogens of respiratory tract infection in Fuzhou area and HMPV and RSV coinfection could be detected. HMPV infected children are older. The clinical features of HMPV and RSV infections are similar. Single genotype of HMPV is detected in Fuzhou area in this study.