Monitoring results of influenza in Xiangxi Autonomous Prefecture, 2018-2022
LI Qi1, QIN Jiabi2, YANG Chan1, MO Yingying1, WU Ge1, YAO Hua1
1. Xiangxi Autonomous Prefecture Center for Disease Control and Prevention, Jishou, Hunan 416000, China; 2. Xiangya School of Public Health, Central South University, Changsha, Hunan 410078,China
Abstract：Objective To analyze the epidemic characteristics and pathogenic monitoring results of influenza in Xiangxi Autonomous Prefecture from 2018 to 2022, and to provide a scientific basis for formulating relevant prevention and control measures in Xiangxi Autonomous Prefecture. Methods Statistical analysis was performed on the monitoring data and pathogen detection results of influenza-like illness (ILI) cases reported by sentinel hospitals in Xiangxi Autonomous Prefecture from 2018 to 2022 based on the China Influenza Surveillance Information System. Results From 2018 to 2022, two sentinel hospitals in Xiangxi Autonomous Prefecture reported a total of 2,050,339 outpatient and emergency visits, including 57,442 ILI cases, accounting for 2.80%. 14,581 respiratory tract samples were collected from ILI cases, and 1,321 samples were positive for influenza virus nucleic acid test, with the positive rate of 9.06%. The detection rates of subtype A H3N2 and subtype B Victoria were higher, with 561 (42.47%) cases and 548 (41.48%) cases respectively. The influenza epidemic in Xiangxi Autonomous Prefecture occurred mainly in winter and spring. The predominant strain of influenza virus in 2018-2019 was influenza A/H1N1. H3N2 and Victoria viruses were co-prevalent in 2019-2020. The dominant strain in 2021-2022 was Victoria, with H3N2 being the prevalent strain after 17 weeks of 2022. Among the population undergoing ILI testing, the positive rate of influenza virus nucleic acid test was found to be the highest in the group aged 5-14 years (13.41%), followed by the group aged 0-4 years (11.23%). There were statistically significant differences in the positive rate of influenza virus nucleic acid test among people in different age groups (P<0.05). Conclusion The high incidence periods of influenza in Xiangxi Autonomous Prefecture were in the winter and spring of 2018-2022, with alternating epidemics of various types of influenza viruses. Children and adolescents are the high incidence population, and influenza prevention and control work should be focused on preschoolers and primary and secondary school students. Clustered outbreaks should be detected in a timely manner, corresponding measures should be actively taken, and timely vaccination should be encouraged to prevent and control the epidemic of influenza.
2024, Vol. 31 
