The Epidemiological Study Of Viral Diarrhea In Sentinel Hospitals Of Guangzhou From2011-2012

Acute viral gastroenteritis is the leading cause of infectious diarrhea in the world. A number of childern dying of gastroenteritis are much higher in developing countries than developed countries. With the continuous development of detection technology and the deepening of the research, viral diarrhea is more and more important in the acute nonbacterial diarrhea accounted for60%.Rotavirus is a major cause of acute non-bacterial gastroenteritis in infants and young children followed by noroviruses(NoV),sapoviruses(SaV),astroviruses(AstV), enteric adenoviruses(AdV).According to statistics, about111million children with diarrhea worldwide were caused by group A rotavirus each year, which the main infection object for children under5years of age. About1～20000at the age of five die of rotavirus diarrhea in children every year in our country. After rotavirus virus, calicivirus are worldwide popular, something with waterborne and foodborne outbreak of gastroenteritis and have a close relationship with its own virulent, and the onset of a self-limiting process.But the strong infectious, it can cause patient death if not treatment timely. Diarrhea caused by enteric adenovirus can occur throughout the year, the seasonal rise in some areas are autumn and winter. Ad41is the predominant strain in some areas, Ad40-based in other areas, non-enteric adenovirus induced diarrhea were also reported.Astrovirus infection is widespread throughout the world, vulnerable groups is given priority with2years old children, feces detection rate of Astrovirus was0.6-26%in children with diarrhea, iatrogenic infection and dissemination, outbreaks also have been reported, there were reports that it is also one of agents of diarrhea in adults in distributing popular.At present there is no special effective vaccine to prevent the above several viral diarrhea, but United States Wyeth for rotavirus-Ledcrei company has developed a more positive effect and safe and reliable tetravalent live vaccine of rotavirus. But there is no specific vaccine against other viruses. The epidemiological study of viral diarrhea in recent years at home and abroad has been widely carried out, but most of the research mainly study within5years old children, researches about people above18years old and foating people less reported. Athough the economy, health care industry are rapid development with the reforming and opening, urbanizing the countryside, especially urban fringe are relatively backward of the economy. Due to the composition of the complex mobility, low levels of knowledge, poor economic conditions, the overallimpact of health care service status of the floating population of the city is not optimistic, the incidence rate of diarrheal disease wasn’t low.In order to study the system of guangzhou children under the age of five and adults over the age of18viral diarrhea trendy characteristics and advantages of the change of the strain, this study prospectively collected in June2011to May2012in children with diarrhea and diarrhea in adult specimens were first virus research, all of these benefit for further provide scientific evidence for strategies of prevention and control of viral diarrhea, and also for the future research and development of vaccine to provide comprehensive background information of the system.Objectives:1. To investigate the infected information and the epidemiological situation of diarrhea virus infection among chidren under5years old and adults above18years old in Guangzhou, from June2011to May2012.2. Analyzing the prevalence and genotype of NoV, AdV, SaV and AstV among chidren under5years old and adults above18years old and diacussing the advantage strains 3. To provide systemaic picture of epidemiology of viral diarrhea in GuangzhouMethods:1. a total of360chidren’s stools under5years old,demographic data and epidemiological information were collected from a community health center in Baiyun district, and the third afflicated hospital in Guangzhou, from June2011to May2012.5～10g or5～10ml stools added2ml PBS buffer and mixed befor split charging to keep storage at-80℃.2. The detection methods of the samples:NVs, AdV, AstV and SaV were tested by using RT-PCR and PCR technologies through using primiers of JV12Y/JV13I, Ad1/Ad2, Mon269/Mon270and SLV5317/SLV5749. The positive products were purified and sequenced the nucleic acid. Homologous sequences of these positive sequences were found in GenBank using blast. The sequences aligned viral sequences by using Clustal W, employing MEGA5.0program package to construct the phylogenetic trees,to get the epidemiological data about NVs, AdV, AstV and SaV infection in Guang zhou.3. Statistics analysis was proformed to use SPSS13.0software to analyse the data from the patients, and count data were compared with chi-quuare test. Test standard was0.05.Results:1. A total of360stools and questionnaires were collected from diarrhea patients under5years old in Guangzhou. Education level of children’ guardians were most middle school. Most children’ guardians were in job-waiting.2. A total of127stools and questionnaires were collected from diarrhea patients above18years old in Guangzhou.the mean age was41.91±17.92.The Education level of patients were most middle school50.39%(64/127), illiteracy was0.79%(1/127) at least, career with office workers accounted for most,25.20%(32/127).3. The detecting rate of of RV, NVs, AdV, SaV and AstV under5years old were30%(108/360)、8.9%(32/360)、7.5%(27/360)、1.7%(6/360)、2.5%(9/360), respectively. The detecting rate of RV was the most. The positive case of five viruses almost concentrated on children under the age of3years. The infectious peak of RV, SaV and AstV were in autumn and winter, of which NV and AdV showed in summer.4. The detecting rate of of RV, NVs, AdV, SaV and AstV above18years old were5.51%(7/127),8.66%(11/127),2.36%(3/127),2.36%(3/127),0.79%(1/127), The detecting rate of NVs was the most. The positive case of five viruses almost concentrated on adults above the age of60years. The infectious peak of RV was from February to January in the next year. the peaks of NV were September and December.the number of AdV, SaV and AstV were too small to analysis the character of the season.5. There were32NoV in360stools, and the analysis of phylogenetic trees and identity calculation showed that26strains belonged to GII-4, in which3strains were GII.4-2006a. Besides,3strains were G-13,1strain was GII-5and2strains were GII-6.6sequenced strains belonged to NoV GI, in which4strains were GI-1, and the other two strains was GI-2.the detection of AdV was27,in which18strains were Ad-41. There were9strains belonged to Non-EAd,in which Ad1, Ad2, Ad12, Ad31were2strains respectively,and the other was Ad7. All of astrovirus belonged to AstV-1.6. there were11NVs in127stools above18years old.11positive NV strains showed that8strains belonged to GII-4, besides GII-b,GII-6,GI-1were1strain respectively.All of AdV and AstV belonged to AdV41and AstV-1respectively.the the the positive rate of SaV was2.36%(3/127), in which2strains were GI-2,the other was GIV.Conclusions:1. Children aged less than five years old and adults above18years old are susceptible to diarrea associated virus after exposure, RV is the most common in children associate to diarrhea,but NV is common in adults.the diseas is mainly infected children under the age of3years,and the old above60years old is susceptible to diarrhea, The Peak season of five virus are different,so long-term survery should be needed. 2. GⅡ.4genetype of NoV was the advantage strain among chidren under5years old and adults above18years old in Guangzhou, in which3strains were GⅡ.4-2006a. GⅡ.4-2006b genetype caused lots of events of outbreak diarrhea in many areas of china. The results showed that AdV41was the advantage strain in Guangzhou, meanwhile, other genetypes of AdV infection were existed in our country. AstV-1was the advantage strain among chidren under5years old and adults above18years old in Guangzhou with infectious diarrhea causing by AstV in Guagnzhou,which was accordant with our counties. GⅠ-1genetype of SaV was the advantage strain in children but GⅠ-2was in adult.The genetypes were various in four virals,attention should be paid.