Abstract: Objective To analyze the incidence trends of category A and B intestinal infectious diseases in Nanjing City from 2005 to 2022,and to provide a basis for formulating prevention and control strategies. Methods The incidence rate of category A and B intestinal infectious diseases in Nanjing from 2005 to 2022 was analyzed by using Joinpoint software. Results A total of 21 094 cases with 7 categories intestinal infectious diseases were reported in Nanjing from 2005 to 2022,and the median annual incidence was 11.06/100 000. The results of Joinpoint regression analysis showed that the total incidence rate of category A and B intestinal infectious diseases continued to decline at an average annual rate of 13.74%. The incidence rate of category A and B intestinal infectious diseases in male[average annual percent change（AAPC）=-13.86,P<0.05]and female（AAPC=-14.19,P<0.05） both displayed a downward trend. The downward trend of incidence rate also be found on aged 0-<20,20-<40,≥60 years old age groups,with AAPC value of 13.01%,16.98%,12.02%,respectively. There was a statistically significant difference in the downward trend of the incidence rate of the 40-<60 age group from 2005 to 2014[annual percent change（APC）=-18.85,P<0.05]. The total incidence rate of category A and B intestinal infectious diseases in the main urban districts and the suburban districts also showed a downward trend,with AAPC value of 13.54% and 14.11%,respectively（both P<0.05）. Conclusion The incidence rates of category A and B intestinal infectious diseases in Nanjing shows a downward trend,while it is still necessary to continue to take precise prevention and control measures to reduce the incidence rate of various intestinal infectious diseases of different gender,age groups and districts.

Key words: Category A and B intestinal infectious diseases, Incidence, Joinpoint regression model