Objective To analyze the epidemic characteristics of scarlet fever in Pudong New Area, Shanghai from 2010 to 2023, and to grasp the incidence of scarlet fever in time. Methods The information on the registration of scarlet fever in Pudong New Area, Shanghai from January 1, 2010 to December 31, 2023 was collected through the China Disease Prevention and Control Information System, and descriptive epidemiological methods and Joinpoint regression model were used for data analysis. Results From 2010 to 2023, a total of 5 669 cases of scarlet fever were reported in Pudong New Area, Shanghai, and no deaths were reported. The annual reported incidence rate was 7.2/100 000, and the overall trend was decreasing year by year. In terms of time distribution, the incidence peaks were in spring and winter. The incidence rate in males was higher than that in females, and it mainly affected children, especially those aged 2 to 10 years. Joinpoint regression model analysis showed that the annual percentage change (APC) and average annual percentage change (AAPC) of the reported incidence rate of scarlet fever from 2010 to 2023 showed that the incidence rate was fluctuating, and the incidence rate decreased significantly from 2019 to 2023 (APC was -53.7%). Conclusion The reported incidence rate of scarlet fever in Pudong New Area in Shanghai has decreased year by year from 2010 to 2023, and children remain the focus of prevention and control.

Objective To evaluate the possible causes of misdiagnosis of minimal breast carcinoma (MBC). Meth-ods The possible causes of misdiagnosis of 90 cases of MBC confirmed by pathology were retrospective analyzed. Accord-ing to the maximum diameter of the lesion, 90 cases were divided into 0.5-1.0 cm group (n=55) and≤0.5 cm group (n=35). And these two groups were subdivided into correct and misdiagnosed groups. The two-dimensional ultrasound findings were observed by using SIEMENZ S2000, GE vivid7 and GE vivid9 color Doppler ultrasound instruments, and reasons of misdiag-nosis were analyzed. Results There were 32 cases were misdiagnosed in 90 patients with MBC. There was significant differ-ence in boundary of misdiagnosis between diameter 0.5-1.0 cm group and≤0.5 cm group. There were significant differences in boundary and calcification between misdiagnosed group and correct group in diameter 0.5-1.0 cm group (P<0.05). There were also significant differences in A/T ratio and accompanying by multiple benign nodules between misdiagnosed group and correct group in diameter≤0.5 cm group (P<0.05). Conclusion The misdiagnosis in MBC is because of different lesion sizes. The misdiagnosis happens in the maximum diameter of the lesions between 0.5-1.0 cm that showed manifestation of sharp edges, no micro-calcification in sonographic features of benign. The misdiagnosis happens in maximum diameter of le-sions≤0.5 cm that manifested as the aspect A/T ratio<1 and characterized by multiple nodules.