RESUMEN
Objective To understand the epidemiological characteristics and genotype distribution of enterovirus (EV) in influenza-negative influenza-like illness (ILI) cases in Chongqing, and to provide a scientific basis for EV prevention and control. Methods Throat swab samples of influenza-negative ILI cases were collected from surveillance sites. The samples were detected for EV using real-time RT-PCR. The VP4 regions of positive samples were amplified and sequenced for genotyping. Results A total of 3 960 influenza-negative ILI samples were collected from January to December 2021, and 316 (7.98%) of them were EV-positive. EV could be detected in influenza-negative ILI cases in Chongqing all year round. The months with high EV-positive rates were January (11.60%), April (10.56%), May (11.79%), June (12.62%), and July (10.33%). There was a statistically significant difference in the detection rate of EV in ILI cases in different regions, gender, and age groups (χ2=29.647，χ2=4.192，χ2=69.176，P<0.05). A total of 213 EV-positive cases were successfully genotyped, including 17 genotypes of EV-A, EV-B, and EV-C and 5 genotypes of HRV-B. The dominant genotypes were CV-A4 (32.86%), CV-A2 (23.00%), CA-6 (12.21%), and CA-10 (11.74%). EV-D and novel EV were not identified in this study. Conclusion EV is an important pathogen in ILI cases in Chongqing. The prevalence of EV in ILI cases in Chongqing has typical regional, seasonal and population characteristics. Prevention and control should be carried out in Chongqing according to the epidemic characteristics of EV.