ABSTRACT
Objective:To analyze the non-enterovirus A71 (non-EVA71) and non-coxsackievirus A16 (non-CVA16) enteroviruses causing hand, foot and mouth disease (HFMD) in Kunming and Qujing of Yunnan Province in 2021 by sequencing the VP4/VP2 and VP1 genes and to analyze the phylogenetic characteristics of the VP1 gene of CVA2, aiming to provide reference for the prevention and control of CVA2.Methods:The samples were made and extracted strictly according to the Laboratory Manual for Hand, Foot and Mouth Disease (China Center for Disease Control and Prevention, 2018 Edition). VP4/VP2 junction regions were firstly amplified and sequenced by MD91/OL68-1 primers. These sequences were firstly edited and then "blasted" on the GenBank to determine the virus serotype. To analyze the phylogenetic characteristics of CVA2, the entire VP1 gene sequences were amplified in two segments using enterovirus species A primers. Virus serotype was again confirmed online by "Enterovirus Genotyping Tool Version 0.1". The sequences of the reference virus genotypes/sub-genotypes were downloaded according to the reference. The phylogenetic trees were constructed by Mega5.2 software and the genetic characteristics were analyzed.Results:A total of 749 non-EVA71 and non-CVA16 enteroviruses were detected in the two areas in 2021. Group A enteroviruses were the main pathogens, with CVA16 as the predominant virus, and a small number of group B enteroviruses were reported. Only five strains of CVA2 were detected with a detection rate of 0.67% (5/749), indicating that CVA2 was a rare pathogen for HFMD in the two areas. The sequencing and serotyping results were consistent using the two genomic regions of VP4/VP2 junction region and VP1 region. Phylogenetic analysis showed that three Kunming strains belonged to genotype A, while two Qujing strains belonged to genotype D.Conclusions:The detection rate of CVA2 in Kunming and Qujing was 0.67% in 2021. CVA2 was a rare pathogen for HFMD in the two regions. Phylogenetic analysis showed genotypes A and D spread in Kunming and Qujing, respectively, but had not caused epidemics. To our knowledge, this was the first report of genotype A of CVA2 in China. Strengthening the laboratory surveillance especially molecular epidemiological surveillance is valuable for the monitor and analysis of transmission source for CVA2.
ABSTRACT
We investigated and analyzed the first case of human infection with avian influenza A(H9N2) virus in Yunnan Province,China,so as to provide a better basis for preventing and controlling human infections with viruses of animal origin in the future.We carried out the field epidemiological survey among the patient,close contacts and the live poultry markets,detected and analyzed the samples from patient and the outdoor environment.Results showed that the 9-month-old boy was a case of human infection with avian influenza A(H9N2) virus with the history of live poultry markets exposure and the results of nucleic acid detection and virus isolation.There was a lot of contamination of the avian influenza virus in the live poultry markets.The second generation cases have not occurred.The monitoring of pneumonia of unknown etiology and influenza like cases in medical institutions is the important means to find timely cases of human infected with avian influenza.Regular disinfection and closing-down of live poultry markets are key measures to reduce the exposure opportunity.
ABSTRACT
Objective To investigate the mutation of hemagglutinin gene and amino acid variation of influenza B.Methods Influenza B virus was isolated from throat swab samples in sentinel surveillance of Yunnan province from 2009 to 2014.HA1 gene sequence analysis was applied to determine 12 randomly-selected strains of influenza B virus.The results were analyzed,MEGA software was used to do homology comparison and HA gene phylogenetic tree was established.Results Differences on the serotype and genotype identification of influenza strains were found and it might be caused by inadequate gene mutation accumulation.Amino acid variations were found in 3 important regions of antigenic determinants in HA1 protein:ring 120,ring 150 and ring 160.The amino acid variation of position 131 in ring 120 was N131K,and in position 137 was N137H.Two strains had P187S mutation in position 187.Conclusion There are some important variations in the hemagglutinin gene of influenza B strains in Yunnan Province,with some variations being the same as vaccine strains and some being not.