To analyze the weekend/holiday attenuation and delayed reporting effects of notifiable infectious diseases in Shapingba district, Chongqing from 2015 to 2024, and to provide evidence for improving the quality of infectious disease reporting in medical institutions.

Data on reported notifiable infectious disease cases in Shapingba District from 2015 to 2024 were collected from the National Notifiable Disease Surveillance System of the China Information System for Disease Control and Prevention. Statistical analyses were performed using R 4.4.2. Pearson χ² tests and Wilcoxon rank-sum tests were employed for inter-group comparisons, while negative binomial regression and linear regression were applied to assess attenuation and delayed reporting effects.

Significant weekend/holiday attenuation and delayed reporting effects were observed for notifiable infectious diseases in Shapingba district. The daily average number of reports during weekends, short holidays, and long holidays decreased by 62.15%, 60.37%, and 69.38%, respectively, compared to workdays. The attenuation effect weakened for weekends and short holidays during 2023—2024. Compared with workdays, the time from diagnosis to reporting was prolonged by an average of 2.58 hours, 2.18 hours, and 2.60 hours. The weekend/holiday reporting delay effect weakened from 2020 to 2022, but re-emerged after 2023. Tertiary healthcare institutions exhibited the most pronounced weekend/holiday attenuation and delayed reporting effects.

Significant weekend/holiday attenuation and delayed reporting effects persist in Shapingba district, particularly in tertiary healthcare institutions. Medical institutions should strengthen the management of infectious disease reporting during weekends and holidays.