Introduction:Measles is the third most common infectious disease,after Smallpox and Polio,and the global health community has committed to eliminating it.Recently,measles recurrence and outbreaks have occurred in seve...Introduction:Measles is the third most common infectious disease,after Smallpox and Polio,and the global health community has committed to eliminating it.Recently,measles recurrence and outbreaks have occurred in several countries,posing a significant challenge for China,which is on the brink of eliminating measles.This study aimed to analyze the genetic characteristics of the D8 genotype of the measles virus(MeV)in Gansu Province in 2024 and provide a scientific basis for measles control and elimination efforts.Methods:Nucleic acid-positive throat swab specimens were collected from measles cases confirmed in 14 municipal measles/rubella network laboratories in Gansu Province in 2024.MeV RNA was directly extracted using a viral nucleic acid extraction kit,and 634 nucleotides at the 3'-terminal of the nucleoprotein gene were amplified using one-step reverse transcription-polymerase chain reaction(RT-PCR).The amplified products were subjected to nucleotide sequencing to characterize the MeV gene.Results:A total of 120 sequences of a 450-nucleotide region within the nucleoprotein gene(N-450)of MeV were obtained from the Measles and Rubella Network Laboratory of Gansu Province in 2024,of which 117 sequences were of the D8 genotype and 3 sequences were of the A genotype.The similarities in nucleotide and amino acid sequences between the D8 genotype sequences were 96.4%–99.1%and 96.7%–98.0%,respectively.The Gansu D8 sequences belonged to the same major branch as the D8 reference strain identified by the World Health Organization(WHO),which further divided into Cluster 1 and Cluster 2.By aligning oligonucleotide sequences using the real-time RT-PCR kit distributed by the Global Measles and Rubella Laboratory Network(GMRLN)with sequences of the D8 genotype from Gansu Province,this study discovered that every sequence in Cluster 1 occurred at the reverse primer annealing site,each containing three T-to-C transitions.Conclusions:The cases detected in Gansu in 2024 were likely imported or linked to importation.It is recommended to continue vaccination programs with measles-containing vaccines in key areas and to carry out highly sensitive etiological monitoring and detection to provide data support for subsequent measles elimination efforts.展开更多
文摘Introduction:Measles is the third most common infectious disease,after Smallpox and Polio,and the global health community has committed to eliminating it.Recently,measles recurrence and outbreaks have occurred in several countries,posing a significant challenge for China,which is on the brink of eliminating measles.This study aimed to analyze the genetic characteristics of the D8 genotype of the measles virus(MeV)in Gansu Province in 2024 and provide a scientific basis for measles control and elimination efforts.Methods:Nucleic acid-positive throat swab specimens were collected from measles cases confirmed in 14 municipal measles/rubella network laboratories in Gansu Province in 2024.MeV RNA was directly extracted using a viral nucleic acid extraction kit,and 634 nucleotides at the 3'-terminal of the nucleoprotein gene were amplified using one-step reverse transcription-polymerase chain reaction(RT-PCR).The amplified products were subjected to nucleotide sequencing to characterize the MeV gene.Results:A total of 120 sequences of a 450-nucleotide region within the nucleoprotein gene(N-450)of MeV were obtained from the Measles and Rubella Network Laboratory of Gansu Province in 2024,of which 117 sequences were of the D8 genotype and 3 sequences were of the A genotype.The similarities in nucleotide and amino acid sequences between the D8 genotype sequences were 96.4%–99.1%and 96.7%–98.0%,respectively.The Gansu D8 sequences belonged to the same major branch as the D8 reference strain identified by the World Health Organization(WHO),which further divided into Cluster 1 and Cluster 2.By aligning oligonucleotide sequences using the real-time RT-PCR kit distributed by the Global Measles and Rubella Laboratory Network(GMRLN)with sequences of the D8 genotype from Gansu Province,this study discovered that every sequence in Cluster 1 occurred at the reverse primer annealing site,each containing three T-to-C transitions.Conclusions:The cases detected in Gansu in 2024 were likely imported or linked to importation.It is recommended to continue vaccination programs with measles-containing vaccines in key areas and to carry out highly sensitive etiological monitoring and detection to provide data support for subsequent measles elimination efforts.
