RESUMO
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.
RESUMO
ObjectiveTo perform the analysis of influenza surveillance in Dehong from 2016 to 2020 and determine the epidemic situation of influenza and prevalent virus strains， so as to provide evidence for local influenza prevention and control. MethodsThe influenza surveillance data in Dehong Prefecture was collected from January 2016 to December 2020. Statistical analysis was conducted by descriptive epidemiological methods. ResultsA total of 4 146 samples from influenza-like illness cases were examined. The 502 specimens tested positive for influenza virus， including 311 cases with influenza A virus and 136 cases with influenza B virus， resulting in a positive rate of 12.11%. The positive rate was the highest in 2017， followed by 2019， and the lowest in 2020 （P < 0.05）. It peaked in winter and fall. Furthermore， it was the lowest among children aged 0‒4 years and the highest among adults aged 25‒59 （P < 0.001）. In addition， positive rate did not differ significantly by gender（P>0.05） ConclusionThe positive rate of influenza has decreased in Dehong since January 2020. The influenza epidemic is seasonal， mainly in fall and winter， except 2020. Influenza A virus is predominant， compared to alternating influenza B virus.