Epidemiology Of Rotavirus And Molecular Characterization Of G5P[6] Strain In Lulong Hebei

Group A rotaviruses are a major cause of acute gastroenteritis in youngchildren and in a wide variety of domestic animals. Rotavirus infection ofhumans causes diarrhea resulting in significant morbidity and mortality,especially in developing countries. Globally, rotavirus is associated with anestimated 611, 000 deaths in young children every year (range 454, 000～705,000). Epidemiological studies have demonstrated that five rotavirus Gserotypes (G1, G2, G3, G4, and G9) and two P serotypes(P[8] and P[4]) are themost frequent VP7 and VP4 types associated with human rotavirus (RV)infection globally. Some uncommon G/P type and rare G/P combination alsohas the report.Although the incidences of rotavirus infection are similar among childrenin developed and developing countries, the fatalities caused by rotavirusdiarrhea occur almost entirely in lessdevelopedregions. Rotavirus infectionsin developing countries also have other noteworthy characteristics, such asthe elevated prevalence of unusual serotypes in some settings. It is necessity ofcontinuous surveillance to allow identification and characterization of novelstrains. Lulong is a halfmountainoushalfruralcounty remote fromindustrialized areas, Lulong hospital is one of surveillance sites nationwide , continuous surveillance and molecular characteristics are important for thedevelopment of rotavirus vaccines.Objectives1. Determine the epidemiologic and clinical features of rotavirus diarrheain children younger than 5 years of age and provide suggestions for preventionand control efforts of RV diarrhea.2. Conduct a molecular epidemiologic study of human and porcinerotavirus stains to determine RV vaccine development.3. Molecular characteristics identified through full genomic analysis ofunusual human rotaviruses in LulongMethodDiarrhea specimens of acute diarrheal children were collected fromidentifies RV stain characteristics. Medical records resources were used toidentify all children who were diagnosed with gastroenteritis or acute diarrheafrom children less than 5 years old in the county during 2000.1～2007.12.All the diarrhea specimens were tested for rotavirus by enzyme linkedimmunity immunosorbant assay (ELISA) and typed by Reversetranscriptionpolymerasechain reaction (RTPCR)using typespecificprimers,analyzed the epidemiologic information with SPSS software. Amplification offull genes sequences of three unusual human strains and a porcine strain.cloned into the pGEMTEasy vecter (Promega). Cloned sequences weredetermined and analyzed with the DNASTAR software package. Phylogeneticanalyses were conducted with MEGA software program version 3.1. ResultsLulong human Rotavirus accounted for 46.55% of all episodes of diarrhearequiring hospitalization. Among all the RV episodes requiring hospitalization,95.52% of them in children less than 2 years old. Rotavirus presented a markedseasonal peak from November to April similar to that observed in othercounties with temperate climates.Lulong human Rotavirus Gserotypingresults showed that G3 (57.93%)was the most prevalent serotype followed by G1 (25.72%). Among 627samples,P[8], P[4] and P[6] types were found in 67.15%, 6.38% and 1.75% respectively.The most common G/P combination identified in this study was P[8]G3(50.23%), followed by PMIXG3(12.92%),P[8]G1 (11.16%) and G2P[4](4.8%). Seven other combinations of minor frequency were alsoidentified(P[4]G1,P[8]G2,P[4]G3,P[6]G3,P[6]G4,P[6]G9,P[8]G9).Lulong porcine Rotavirus accounted for 26.16% of all tested samples.Gserotypingresults showed that G5 (23.75%) was the most prevalent serotypefollowed by G3 (8.75%),G9 (8.75%) and G4 (8.00%). Among 471 samples,P[13], P[6], P[8] and P[23] types were found in 22.50%, 13.75%, 12.50%and 3.75% respectively. The most common G/P combination identified in thisstudy was P[13]G5 (17.50%), followed by P[8]GNT (8.75%),P[6]G4 (2.50%)and G9P[6](1.25%). Nine other combinations of minor frequency were alsoidentified(G3 P[23],G 1 P[6],G 1 P[8],G 4 P[6],G 4 P[8],G 4 P[23],G 5 P[6],G9 P[6],G9 P[13]和G9 P[23]).Lulong human three unusual strains were characterized to be of G5P[6]genotype. The sequences of the three lulong human G5P[6] strains were closestto counterparts in the lulong porcine G5P[6] strains. Phylogenetic analysis of lulong three unusual human G5P[6] strains sequences clustered with Lulongporcine G5P[6] strain.DiscussionRotavirus infection was the most common cause of severe gastroenteritisamong children younger than 5 years of age. In order to reduce severegastroenteritis and mortality caused by rotavirus, It is important to develop andimplement rotavirus vaccine to prevent and control RV infection in China.Because of the diversity and complexity of RV strains circulating in LulongChina. This research demonstrated that the best time for taking the vaccine isunder 6 months.In addition, we discovered many rare G/P combination porcine RV strainsthrough type determination and gene analysis. It helps us to understand theepidemiology characteristics and the change tendency of porcine RV, and tounderstand the relationship between human RV strains and porcine RV strains,and also, it is of great importance for RV vaccine development.Similary, human rotavirus G5 serotype is the first identification in Asiaand the data presented were the first demonstrating G5P[6] rotavirus at thelevel of nucleotide sequence in the word. Analysis molecular characterizationof Lulong unusual human G5P[6] rotaviruses and porcine G5P[6] rotavirusescorroborate the notion that human and porcine rotaviruses interact with oneanother dynamically leading to the introduction of porcine rotaviral genealleles into human viruses. Moreover G5P[6] strains maybe gradually becomenew RV popular superiority after G9 type, and possible influence for the RVvaccine application and the development, we should carry on the longtermdynamic monitor to trace its popular and the evolution. This study indicates that there is a constant flux of genetic materials among cocirculatinghumanand animal rotaviruses. In this regard, The study also provides new insight onthe diversity of rotavirus strains circulating in human population and hasimplications for rotaviral pathogenesis.