Epidemiological Study On Viral Diarrhea Among Infants And Young Children In Lanzhou

Background:Gastroenteritis disease is a major cause of childhood morbidity and mortality.Globally almost 2.1 million infants and young children are believed to die of gastroenteritis-related disease or complications every year.Rotavirus and adenovirus,astrovirus,calicivirus virus have been recognized as the most important pathogen of viral diarrhea,rotavirus is recognized to the single most important pathogen associated with severe dehydrating gastroenteritis.Vaccine is the only viable prevention and control of the high morbidity and mortality of the method,different years,different regions have a greater prevalence of variant strains,long-term monitoring system is essentialObjectives:Epidemiological study on common diarrheal viruses was conducted in Lanzhou,China,from 2007 to 2008,that provided the evidences for prevention and treatment to virus diarrhea.Methods:In the first hospital of Lanzhou university from Jul 2007 to Jun 2008,346 stool specimens were collected from children hospitalized with diarrhea and 100 asymptomatic childrens.Rotavirus was detected by ELISA,further strain characterization was carried out by nested PCR.The detection of calicivirus, astrovirus,adenovirus and group B,C rotavirus were detected by RT- multiplex PCR and PCR and the positive specimens were characterized by nucleotide sequencing.Results:There are rotavirus,adenovirus,human calicivirus,and astrovirus were found in 346 specimens,The positive rates is 52.0%(180/346).They are rotavirus 41.9% (145/346),adenovirus 7.2%(25/346),human calicivirus 6.1%(21/346) and astrovirus 5.8%(20/346) respectively,co-infection were found in 8.1%(28/346); Rotavirus G3(64.7%) was the most prevailing serotype followed by G9(19.3%),in the P genotype,P[8](69.7%) was the most common genotype,The most common G-P combination was G3P[8](30.3%) followed by G9P[8](8.1%).The overall prevalence of calicivirus infections indicated that norovirus GII/4(47.6%) was main strains,NV GI/14 and NV GI/5 were the first time detected in Lanzhou,NVGI/14 has not been reported in China.All astrovirus belonged to genotype 1.The percentage of adenovirus increased distinctly in this year,Ad41 were the most prevalent serotype. Nother group B nor C rotavirus was detected.In the 100 samples of control group,there are 1 rotavirus,1 astrovirus and 1 Adenovirus were detected,and their serotype and genotype were coincident with that in the concrol group,viral diarrhea patient occurred in infant under 2 years of age.A peak admission of rotavirus diarrhea was observed from September to December.Conclusion:Rotavirus was also the most important pathogen,but the adenovirus should be given more attention.The predominant rotavirus strain circulated was G3P[8]followed by G9P[8],which was different from the finding in the previous years.NVGI/14 and NV GI/5 were the first time detected in Lanzhou,NV GI/14 has not been reported in China.