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Objective:To investigate the epidemiology of pathogens of acute respiratory tract infection (ARTI) in children in Guangzhou area.Methods:A total of 13 610 hospitalized children with ARTI in Guangzhou Women and Children′s Medical Center from January 2018 to December 2021 were enrolled. Throat swab specimens were collected, and fluorescent quantitative polymerase chain reaction (PCR) was performed to detect 11 respiratory pathogens, including respiratory syncytial virus (RSV), adenovirus (ADV), parainfluenza virus (PIV), human rhinovirus (HRV), human bocavirus (HBoV), human metapneumovirus (HMPV), enterovirus (EV), influenza A virus (IFA), influenza B virus (IFB), Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP). Grouping according to age (< one year group, one to < three years group, three to < six years group, six to 14 years group) and season. Chi-square test was used for statistical analysis. Results:At least one pathogen was detected in 6 331 cases among 13 610 patients, and the overall positive rate was 46.52%. The detection rates from high to low were as follows: RSV (13.75%(1 872/13 610)), ADV (4.82%(656/13 610)), PIV (4.82%(656/13 610)), MP (4.54%(618/13 610)), HRV (3.39%(462/13 610)), HBoV (2.64%(359/13 610)), HMPV (2.59%(352/13 610)), EV (1.76%(239/13 610)), IFA (1.29%(176/13 610)), IFB (0.90%(122/13 610)) and CP (0.30%(41/13 610)). The positive rate of viral detection showed significant differences among different age groups ( χ2=49.91, P<0.001), and the highest positive rate was in the age group of one to <three years (50.83%(2 196/4 320)). The positive rate of viral detection showed a significant difference in terms of seasonal distribution ( χ2=13.90, P=0.003), with a peak prevalence in summer (48.76%(1 498/3 072)). Conclusions:RSV, ADV, PIV, MP and HRV are important pathogens causing ARTI in children in Guangzhou area. The distribution of pathogens in children with ARTI is associated with age and season.
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Objective To study the epidemiology of hand,foot,and mouth disease (HFMD) and the spectrum of serotypes in the other enterovirus (EV) (non-EV-A71 and non-Coxsaekievirus group A 16,CV-A 16) from 2016 to 2017 in Guangzhou,to provide the basis for its treatment,prevention and control.Methods Enteroviruses universal type,EV-A71 and CV-A16 were detected by real time reverse transeription-polymerase chain reaction in the specimens from HFMD suspected patients from 2016 to 2017.The positive specimens of non-EV-A71 and non-CV-A16 were amplified and sequenced based on 5'-untranslated region (UTR) region.The spectrum of serotypes was analyzed with BLAST in NCBI on the basis of 5'-UTR region.Results A total of 25779 specimens from HFMD patients were collected during 2016-2017,16 300 (63.23 ％) of which were positive.The positive rates of EV-A71,CV-A16,non-EV-A71 and non-CV-A16 were 4.57％ (1 178/25 779),12.70％ (3 274/25 779) and 45.96％ (11 848/25779),respectively.The average positive rate of non-EV-A71 and non-CV-A16 in 2017 was 55.68％,which was higher than that in 2016.Sequence analysis showed that there were 16 genotypes in 95 non-EV-A71 and non-CV-A16 positive specimen,including CV-A6,CV-A10,CV-A4,CV-A2,CV-A8,CV-A12,CV-A9,Coxsakievirus B5 (CV-B5),CV-B2,CV-B4,CV-B3,Echovirus 1 (E1),E16,E30,E2 and E18.CV-A6 (26.32％),and CV-A10 (15.79％) were the most common genotypes,followed by CV-A4 (6.32％)、CV-A8(4.21％),and CV-A2 (4.21％).Conclusions The infection rate of EV-A71 is very low during 2016-2017.From April to July 2016,there is a small peak of CV-A16 infection.The non-EV-A71 and non-CV-A16 enterovirus becomes the main causative agent of HFMD during 2016 to 2017.CV-A6 and CV-A10 are the most prevalent pathogens of non-EV-A71 and non-CV-A16 enterovirus.Research and monitoring of CV-A6,CV-A10 as the main non-EV-A71and non-CV-A16 virus should be strengthened.
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ObjectiveTo conduct a molecular epidemiological study on human metapneumovirus (hMPV) among pediatric patients in Guangzhou. MethodsA total of 1 840 clinical specimens were obtained from pediatric patients with respiratory infections in Guangzhou Women and Children' s Medical Center in 2010.hMPV was detected by real-time TaqMan RT-PCR in clinical specimens.F gene was amplified and the PCR-products were directly sequenced. ResultsIn 1 840 clinical specimens, 66 werehMPV-positive with a positive rate of 3.59％. hMPV was detected in all specimens except those collected in September and October, and the highest positive hMPV rate occurred in April (6.09％). The F genes of 3 randomly selected strains and hMPVgz01 ( isolated in 2008) were compared with subgroups A1, A2, B1,B2 and C, and the highest homology was with BJ1887 strain of genotype A2b (97％). The F genes of the randomly selected strains and hMPVgz01 were 99％ identical to each other. Sequences and phylogenetics analysis revealed that the epidemical strain in Guangzhou belonged to genotype A2b. ConclusionhMPV is prevalent in spring and summer among children in Guangzhou, and A2b is the predominant genotype.
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Objective To study the genomic molecular organization and genogroup of human metapneumovirus(hMPV) infected infants in Guangzhou of China. Methods Primers were designed on the basis of the genomic sequence of hMPV 00-1 strain(AF371337) in the GenBank, and amplify hMPV genomeby RT-PCR. The PCR-products were cloned to T vector and sequenced, the genomic nucleotide sequences were analyzed with the programs Clustal W/X, DNASTAR and MEGA4. 1. Results The cloned strainhMPVgz01 genome is 13 327 bp in length, the genome contains eight open reading frames in the order 3-N-P-M-F-M2-SH-G-L-5. The genomic sequences of hMPVgz01 strain are compared with those of hMPV in GenBank, revealed that the homology with hMPV group A ranges between 92%-97%, homology with group B is 81%, and with avian metapneumovirus group C is 71%, the highest homology is with BJ1887 strain of genogroup A2b. The N, F, G genes of hMPVgz01 strain are compared with those corresponding genes of hMPV subgroups A1, A2, B1, B2, revealed that the highest homology is also with genogroup A2b. Conclusion The complete nucleotide sequence of hMPVgz01 strain isolated from Guangzhou in China is 13 327 bp in length, GenBank accession No. is GQ153651. Comparison of the genomic sequence and three genes of hMPVgz01 strain with those corresponding sequences of hMPV show the highest homology is with genogroup A2b. Sequence and phylogenetic analysis of the hMPVgz01 strain revegled that this isolate belongs to genogroupA2b.