Rotavirus A pathogen surveillance and gene typing analysis in Kunming city of Yunnan province from July 2014 to June 2015 / 中华实验和临床病毒学杂志

ABSTRACT

Objective@#To analyze the infectious status and etiological characteristics of rotavirus A (RVA) from children less than five years old in the Kunming city of Yunnan province from July 2014 to June 2015, to provide basic data and methodological references for the disease surveillance, and controling outbreak cases investigations as well as vaccine research and development.@*Methods@#Stool samples were collected from 1 121 diarrhea cases and 319 healthy controls in four sentinel hospitals and transported to laboratory. Two-step reverse transcriptional polymerase chain reaction (RT-PCR) was used to detect the presence of RVA in each stool specimen. Suspicious positive specimens of gel electrophoresis was further sequenced to make definite diagnosis of RVA infection. Each RVA positive stool specimen was confirmed with sequencing which was conducted the semi-nested multiplex RT-PCR to detect six G genotypes and six P genotypes.@*Results@#Total 244 samples from the 1 212 diarrhea patients were detected positive for RVA and the total positive rate was 21.8%. G typing of group A rotavirus mainly showed G9(66.4%, n=156), G3(18.7%, n=44), G1(8.9%, n=21)and G8(1.7%, n=4). P typing mainly showed P[8](92.8%, n=218)and P[4](4.7%, n=11); G/P combination genotypes were composed mainly of G9P[8](57.0%, n=134), G3P[8](18.3%, n=43) and G1P[8](8.9%, n=21). The detection rate of RVA in diarrhea patients had obvious seasonal distribution (χ2=46.3, P<0.001), with the prevalent peak in winter (31.2%), and the seasonal distribution of G9P[8](χ2=27.3, P<0.001), G1P[8](χ2=8.2, P<0.039)and G3P[8](χ2=10.2, P<0.042) had strong seasonal pattern with a peak in winter equally. In the subjects under five years, the detection rate of G9P[8](14.9%, 2.9%, χ2=18.1, P<0.001) and G3P[8](4.4%, 0.5%, χ2=5.6, P<0.018) from diarrhea cases were higher than that of in healthy controls, respectively.@*Conclusion@#There existed rather high infection rate of RVA in acute diarrhea cases in Yunnan province, which can be divided into a variety of genotypes, G9P[8]was the dominant genotype.