| Objectives To explore the epidemic characteristics of viral diarrhea in children under 5 years of age in Sanjiang,Guangxi province,a population-based surveillance was carried out,aiming to provide scientific basis for the control and prevention of viral diarrhea.Methods 1 From January to December 2013,a population-based surveillance,active and passive monitoring activities were carried out.Clinical information and stool samples were collected from patients under 5 years of age living in 26 villages of 2 townships;2 The virus RNA/DNA was extracted by magnetic bead method,Reverse Transcription-Polymerase Chain Reaction(RT-PCR)method was applied to detect Human Rotavirus,Human Caliciviruses,Human Astrovirus and Picobirnaviruses,Polymerase Chain Reaction(PCR)method was applied to detect Human Enteric Adenovirus.For the positive sample,the PCR product was sent to sequence to confirm the genotype;3 According to the results of laboratory tests combined with demographic data,the molecular epidemiological characteristics of diarrhea patients less than 5 years of age were analyzed.The severities of viral diarrhea were evaluated ground on symptoms and the clinical signs.The relationship between genotype and the clinical symptom severity was judged by clinical signs.Results 1 Basic Results: In January to December 2013,the total number of children under 5 years of age in the monitoring area was 3108,among them,1258 diarrhea occurred,1216 children’s stool samples were collected,318 cases were positive for diarrhea virus,and the total detection rate was 26.15%.The detection rates of rotavirus,calicivirus,enteric adenovirus and astrovirus were 11.8%(144/1216),8.06%(98/1216),6.41%(78/1216)and 1.70%(21 / 1216),Picobirnaviruses was no positive samples.There were 22 cases of mixed infection of two kinds of diarrhea virus.Among them,15 cases of mixed infection were two viruses,of which 10 cases were Hu CV mixed HEAdv,3 cases were Hu CV mixed HRV,2 cases were Hu CV mixed HAst V,and 6 cases were HRV mixed HEAdv.There was 1 case of mixed infection with three virus,which were HRV,Hu CV and HAst V;2 Epidemiological characteristics: HRV,Hu CV,HEAdv diarrhea can occur throughout the year and the peak of incidence mainly concentrated in autumn and winter.HAst V infection has obvious seasonal distribution characteristics,and it mainly distributed in December in winter,accounting for 76.19 %(16/21)positive cases.The incidence of four viral diarrhea among children less than 5 years of age was HRV 46.33/1000(144/3108),Hu CV31.53/1000(98/3108),HEAdv23.03/1000(78/3108),HAst V 6.76/1000(21/3108),and the incidence peak were mainly concentrated in the 6-23 months of age;3 Clinical features: Clinical features of viral diarrhea in children less than 5 years of age mainly diarrha,vomiting,and fever and so on.The number of diarrhea and vomiting in children of HRV,Hu CV,HEAdv and HAst V were 43(29.9%,43/144),19(19.4%,19/98),17(21.8%,17%)and 2(9.5%,2/21)respectively,and the number of fever was 41(28.50%,41/144),22(22.4%,22/98),26(33.3%,26/78)and 3(14.3%,3/21)respectively.The maximum number of diarrhea in 24 hours was 14,13,13 and 7respectively;4 Genotype features: HRV G serotype was successfully typed 130 cases,among which the number of G1 serotype was 49(34%),G2 serotype was 16(11.1%),G3 serotype was 27(18.8%),G9 serotype was 36(25%),and G2+G9 mixed serotype was 2(1.4%).There was no G4 serotype.HRV P genotype was successfully typed 105 cases,among which the number of P[4] genotype was 17(11.8%),and P[8] genotype was 88(61.1%).There was no P[6],P[9]and P[10].The most common genotype of No V was GII.6(45%,24/53),followed by GII.4(43%,23/53);The most common genotype of Sa V was GI.1(30%,11/37),followed by GII.1(22%,8/37);Ad40(51%,40/78)was the most common genotype of HEAdv,followed by Ad5(20%,16/78),Ad41(10%,8/78),Ad1(9%,7/78);As2(47.62%,10/21)was the most common genotype of HAst V,followed by As1(28.57%,6/21).Conclusions HRV is the most commen pathogen of diarrhea in children under 5 year,followed by Hu CV and HEAdv.The main genotypes of children with diarrhea are HRV G1P[8],No V GII6 and HEAdv Ad40;HRV,Hu CV epidemic peaks are autumn and winter,HAst V infection mainly in winter,and HEAdv infection has no obvious seasonal distribution characteristics;children under 2 years of age are at high risk of viral diarrhea;Clinical symptoms of diarrhea in children less than 5 years of age are diarrhea,vomiting and Fever,and rotavirus is the main cause of severe diarrhea. |
