Ongoing epidemic of scarlet fever in Shanghai and the emergence of M1UK lineage group A Streptococcus: a 14-year surveillance study across the COVID-19 pandemic period

作者：Jiehao Cai, Xingyu Zhou, Chi Zhang, Yue Jiang, Panpan Lv, Yibin Zhou, Mingliang Chen, Mei Zeng · 发表于：The Lancet Regional Health - Western Pacific · 年份：2025 · DOI：10.1016/j.lanwpc.2025.101576 · 被引用次数：4 · 研究领域：Streptococcal Infections and Treatments、Neonatal and Maternal Infections、Infective Endocarditis Diagnosis and Management

Background The surge of group A Streptococcus (GAS) infections in regional countries warranted attention in the post-COVID-19 era. The resurgence of notifiable scarlet fever in China has been a public health issue since 2011. We conducted a consecutive 14-year surveillance study to analyse dynamic epidemiological profiles of scarlet fever from the perspective of epidemic trend and molecular evolution of GAS strains. Methods From 2011 to 2024, epidemiological data on notifiable cases of scarlet fever and 3370 GAS isolates from children with scarlet fever were analysed. Incidence rates were calculated as the mean rate per 100,000 population with 95% CIs. Whole genome sequencing was performed on 332 emm 12 and 248 emm 1 isolates. Findings From 2011 to 2024, a total of 25,539 cases of scarlet fever were reported in Shanghai. The mean incidence declined from 17.1/100,000 population (95%CI 9.7–24.3, pre-COVID-19 period) to 4.8/100,000 population (2.0–10.1, post-COVID-19 period). Children aged 4–9 years represented 85.6% of cases. Sixteen emm types were identified with predominance of emm 12 (66.4%) and emm 1 (29.8%). The annual proportions of emm 12 and emm 1 alternatively fluctuated with a cycle of six years. GAS isolates displayed >90% resistance rate to erythromycin, clindamycin, and tetracycline. The distribution of emm types, antimicrobial resistance rates and profiles, and differences in superantigen genes carried by the emm 12 and emm 1 isolates were similar in the pre- and ...