Respiratory Syncytial Virus And Human Metpneumovirus Infections In Children With Respiratory Tract Inflammation

Part I Respiratory Syncytial Virus Infections in Children with Acute Respiratory Tract InflammationObjective To understand what's the position respiratory syncytial virus (RSV) occupied in the common viruses leading to the respiratory tract infections in children and define its molecular epidemic features in Urumchi. Methods Samples were collected from November 2006 to April 2007 in the People's General Hospital of Xinjiang Uygur Autonomous Region,including 112 respiratory secretions and 280 nasopharyngeal swabs.At first, direct immunofluorescence was done to detect seven common respiratory viruses in 112 respiratory secretions. Then the nucleic acid was extracted from all 392 samples.After that, it was changed into cDNA by reverse transcription. At last the segment of RSV G gene was amplified by nested PCR. The five positive amplicons selected randomly from all positive samples were sequenced and compared with other RSV in GenBank by Blast and DNAstar. Results The results of direct immunofluorescence indicated that RSV accounted for 27.6%(31/112)and the other viruses accounted for 10.7% ,while the cocurrent infections occupied 3%(3/112). Of all 392 spicimens, 68 RSV G gene segments were tested. Among them, lineage A RSV occupied 93.3%,B occupied 6.7%.The identities between them were 63.6-99.4%. Phylogenetic analysis defined that they belonged to two different clusters. Conclusion 1.RSV was the most important viruses during winter and spring from 2006 to 2007.2.Lineage A was the prevalent genotype of RSV in our area during this epidemics. 3. A and B lineages of RSV can coexist in one epidemic season. Part II Human metapneumovirus infections in children with acute respiratory tract inflammationObjective To research whether human metapneumovirus (hMPV) was one of the virus pathogens leading to the children's respiratory infections in Urumchi and its molecular epidemic statement.To know whether RSV and hMPV exist concurrent infection in our area. Methods Extracting nucleic acid and reverse transcription were done as the first part. Then cDNA was used to amplify hMPV M gene by PCR. The positive PCR amplicons were sequenced and compared with other hMPV in GeneBank by Blast and DNAstar. Results Of all 392 samples, two positive were tested. The identities between these two positive amplicons and the other hMPV were 83.8%-99.3%. Phylogenetic analysis showed that they might belong to two different clusters. Conclusion 1. hMPV was one of the virus pathogens leading to the children's respiratory tract infections in Urumchi.2.Two different hMPV groups can exist in one season. 3. Concurrent infections of RSV and hMPV were not found in our research.