Epidemiology And Clinical Presentation Of Respiratory Syncytial Virus, Parainfluenza Virus And Human Metapneumovirus In Guangzhou

Respiratory tract infections are a leading cause of morbidity and mortalityworldwide. All classes of microorganisms including viruses and bacteria are capableof infecting the respiratory tract. In the past, bacteria were regard as the predominantpathogens found in respiratory diseases, but more and more new emerge viruseschange this mind. Paramyxoviridae are the leading cause of ARTIs in children, elderlyand immunocompromised patients worldwide, which can cause many respiratorydiseases.It is important to obtain Paramyxoviridae isolated strains so that we can dofurther study.And epidemilogy of Paramyxoviridae is a little different in differentregions.few paper report that in Guangzhou.Secondly,hMPV may be underestimatedin the past research.Our aim is to develop culture methods of Paramyxoviridae,andfind out whether hMPV is underestimated or not by compare the epidemilogy,clinicalpresentations of hMPV to RSV and PIVs.MethodsNasopharyngeal swabs were collected from the patients with ARTIs between July2009and September2011testing by real-time reverse transcription–polymerase chainreaction (real time-PCR). The RSV and PIVs positive samples were used to culture byHEp-2and LLC-MK2cell. And hMPV cultured by Vero-E6cell, different to RSV andPIVs, which need to passage three times. Patients’ clinical manifestations wererecorded for further analysis.Results5424nasopharyngeal swabs samples were collected from patients who wereARTIs, and5115patients were enrolled our study. Of5115nasopharyngealsamples(male:female=3094:2027) ranging from1day to91years old were detectedover the whole study period,3089detected from young children(<15years) and2022were from adults.175samples (3.4%) were positive for hMPV, lower than RSV andPIVs,576(10.4%) and205(4.0%).Our study succeed to set up cell culture methods to for RSV, PIVs and hMPV.We get14RSV strains,19PIVs strains and3strains hMPV.92.2%Paramyxoviridae positive samples came from children and28.5%children infected Paramyxoviridae, higher than adults,3.7%(75/2022). Children whowere positive for RSV were younger than those who infected PIVs or hMPV, whilechildren infected hMPV were oldest.hMPV was detected mostly from Januray to May. RSV was the predominant inthe whole study period, two season peak were detected during July to October andDecember to April. The subtypes of PIVs were PIV1and PIV3, mainly focused onsummer and autumn.Influenza, EV, HCoV and MP were the viruses detected frequently in the dualinfection cases. The clinical presentations of patients were similar. The leadingsymptom was fever, followed by cough, expectoration, diarrhea, poor appetite andabnormal pulmonary breathing sound.The clinical characteristics of children weremuch severer than adults, most of them were diagnosed as pneumovirus, and childreninfected hMPV showed fever and abnormal pulmonary breathing sound frequentlythan other two viruses in children. While adults which mainly showed full bodysymptoms, patients who were positive for hMPV seemed much severer than RSV.ConclusionsOur study succeeds to set up methods to culture RSV, PIVs and hMPV. Thedetection rate of hMPV was lower than RSV and PIVs, but we found hMPV is asmuch important as RSV and PIVs by comparing the clinical presentations，especiallyfor children and the elderly.