Detection And Analysis Of HMPV And HCoV-OC43 In Children With Acute Respiratory Tract Infections By FQ-PCR

ObjectiveThe aim of this study was to establish FQ-PCRs to detect human metapneumovirus(HMPV) and HCoV-OC43 and investigate the prevalence and clinical feature in children with acute respiratory tract infections (ARTL) associated with the viruses in Fuzhou areas.MethodsA total of 176 nasopharyngeal swab samples were collected from children visited Fujian Provincial Hospital with ARTL during the period of Oct.2007 to Apr.2008. Out of the 176 children, 118 were with AURTI, 31 were with bronchiolitis,21 were with pneumonia,6 were with asthma.FQ-PCRs for detection of HMPV and HCoV-OC43, targeting at N genes, were established with evaluation of their sensitivity , specificity and reproducibility. Parts of positive PCR products were randomly selected for DNA sequencing analysis.Results1.The sensitivity of FQ-PCR was 102copies/μl for detecting HMPV.The CV of inter-assay and intra-assay were 0.18% and 1.98% respectively.2.In the 176 samples, 29(16.5%) were positive for HMPV .The nucleotide sequence of the HMPV PCR products was 100% homology with that of the reference strains in the GenBank.3.The positive rate of HMPV infection in AURTI group was 15.3%(18/118),in bronchiolitis group was 19.4%(6/31),in pneumonia group was 19.0%(4/21),in asthma group was 16.7%(1/6). Twenty-one (75.8%) children with HMPV positive were aged≤2 years.The seasonal predominance of HMPV infection was from November to March. It was up to the peak in January. 4.The sensitivity of FQ-PCR was 102copies/μl for detecting HCoV-OC43.The CV of inter-assay and intra-assay were 0.53% and 1.46% respectively.5.In the 176 samples, 8(4.5%) were positive for HCoV-OC43. The nucleotide sequence of HCoV-OC43 PCR products was 100% homology with that of the reference strains in the GenBank.6.The positive rate of HCoV-OC43 infection in AURTI group was 5.9%(7/118),in pneumonia group was 4.8%(1/21).Six (75%) children with HCoV-OC43 positive were aged≤1 year.The seasonal predominance of HCoV-OC43 infection was from October to January. It was up to the peak in December.Conclusions1.Both HMPV and HCoV-OC43 were the important pathogens in children with ARTI in Fuzhou from winter 2007 to spring 2008.2.ARTI associated with HMPV ordinarily showes as bronchiolitis and pneumonia besides AURTI. HMPV tends to be prevelant in children≤2 years old. ARTI related with HCoV-OC43 mostly exhibits as AURTI. HCoV-OC43 is more likely to infect children≤1 year old.3.The method of FQ-PCRs for detecting HMPV and HCoV-OC43 was established with satisfactory senstivity, reproducibility and specificity.4.It is suggested that detection of HMPV and HCoV-OC43 might be the routine work for children with ARTI.