ABSTRACT
@#ObjectiveTo analyze the epidemiological regularity of measles in Jilin Province from 2009 to 2022,so as to provide evidence for measles prevention and control measures.MethodsThe representative strains of measles from 2009 to2022 in Jilin Province were sequenced,the dominant epidemic strains and their variation were analyzed by bioinformatics software Bioedit and Mega 11,and the morbidity,immunization history and age distribution of the confirmed cases were analyzed by descriptive epidemiological method.ResultsA total of 6 560 cases of measles were reported in Jilin Province from 2009 to 2022,of which 50. 17% and 27. 58% were cases with zero doses of measles vaccine and unknown immu-nization history,respectively. Children aged 0 ～ 23 months accounted for 47. 29% of the total number of cases,adult group aged ≥15 years accounted for 37. 41%. The reported incidence reached the elimination level of < 1 per million population in the last 3 years due to the impact of immunization strategies and COVID-19 pandemic. The dominant genotype of measles virus in Jilin Province was still H1a genotype. Molecular epidemiological analysis showed that two large transmission chains continued to be prevalent together,one of which was blocked in 2015.ConclusionFrom 2009 to 2022,the reported incidence of measles in Jilin Province showed a downward trend,and the age of the cases showed a "two-way shift" distribution,which was concentrated in the population with no immunization history and unknown immunization history. The basic vaccination rate should be increased continuously,the targeted enhanced immunization should be carried out,and the molecular epidemiological surveillance should be strengthened to block transmission chains in time.