The Molecular Epidemiology Of Human Rotavirus Among Children In Chongqing, 2015

Objective: To determine the prevalence situation and clinical characteristics of rotavirus,associated acute viral diarrhea in children,and analyze the genotypes in Chongqing, China.,2015. it is important for further explore the RV infection epidemiology regularity, identification of rotavirus infection, and the prevention and treatment for rotaviruses.Methods: Five hundred and fifteen fecal samples, from Jan.2015 to Dec.2015, were collected from children with acute diarrhea at the Children’s Hospital of Chongqing Medical University. All samples were tested for rotavirus A by ELISA, The Rotavirus-positive nucleic acids were detected using reverse transcrip-tion polymerase chain reaction(RT-PCR), to determine the G(VP4)、P(VP7) genotypes.Results: A total of 515 fecal samples were collected(male 293,female 222),The ratio between male and female 1.3:1. In all 515 case, 220 stool samples positive for rotavirus were detected by ELISA,ratio were 42.72%(220/515),of which 112(38.23%) of 293 originated from males and 108(48.65%) of 222 from females(χ2=5.608,P>0.05).RV was found Through the whole year, In January, February, November and December were the peak time,the detection rate of RV was significantly difference between different month(χ2=53.693,P=0.00).The positive rate at the age group between 13-18 month was higher than other groups,and children under 2 years old of the total positive cases accounted for 87.27% and under 5 years old of the total positive cases accounted for 98.18%. the detection rate of RV was significantly difference between age(χ2=53.693,P=0.00). before see a doctor,diarrhoea lasted for 4 days in majority of cases(78.6%).RV enteritis always accompanied by vomiting,vomiting was present in over 60.9% of all rotavirus diarrhoea while vomiting was absent in 39.1% of the cases. Chi-square analysis indicated significant association between rotavirus diarrhea and vomiting( < 0.05). that majorityof the children suffering from rotavirus diarrhoea had either fever(18.6%) or fever and respiratory symptoms(25.5%). The prevalence of rotavirus diarrhoea in children showing respiratory symptoms without fever was 40%. Chisquare analysis did not indicate any significant association between rotavirus diarrhoea and these symptoms(P> 0.05).220 samples RV-positive for both the VP7 and VP4 gene fegments by RT-PCR,of which 110 cases were succeed(50%).G9(50%) was the predominant G-type, followed by G3(17.3%),G1(2.7%),G2(0.9%),untype(29.1%);P[8](95.5%) was the predominant P-type, followed by P[4](4.5%); G/P combination genotype were G9P[8](48.2%),followed by G3P[8](16.4%),G1P[8](2.7%),G9P[4](1.8%),G3P[4](0.9%),G2P[4](0.9%)。Conclusion: The study results showed that RV were the major cause of diarrhea in children, in Chong Qing,2015. that majority of cases were the children under 5 years old, especially with 6 months to 2 years old infants and young children.The RV infection has obvious seasonal, the peak seasons were November, December and January.Vomiting is another relative specificity Symptoms besides diarrhoea, fever and respiratory symptoms did not indicate any significant association between rotavirus diarrhoea.The research indicated that G9 is the advantage popular G –genotype, followed by G3, G1, G2. P[8] is the advantage popular P-genotype, followed by P4], did not check out the P [6].G/P combination genotype G9P[8] was the advantage genotype in Chong Qing,2015, followed by G3 P [8], G1 P [8], G9 P [4], G3 P [4], G2 P [4]. The RV genotyping different from regions and time, especially the G gene has obvious diversity, but P genotypes is relatively stable. The research is important for further explore the RV epidemiology regularity, identification of rotavirus infection, and the prevention and treatment for rotaviruses.