Temporal trends of scarlet fever in China from1950 to 2022
Objective To analyze the temporal trends of scarlet fever,including long-term trends,seasonality,and periodicity,and to explore the epidemiological patterns of scarlet fever to provide a reference for prevention and control.Methods Based on statutory reported infectious diseases data,the time-varying patterns of scarlet fever incidence in different regions and age groups from 1950 to 2022 were described in segments.Results The incidence of scarlet fever fluctuated dramatically between(0.59-27.51)/100 000 in 1950-1983.The incidence gradually declined and stayed low in 1984-2003,with an average annual incidence of 2.68/100 000.From 2004-2019,the incidence rebounded and saw a sudden rise in 2011,peaking at 5.89/100 000 in 2019.The average annual incidence in 2020-2022 decreased to 1.60/100 000.The case-fatality ratio showed a downward trend,gradually decreasing from 0.084 in 1950 to less than 1/10 000.The average incidence was 11.56/100 000 in the North and 3.12/100 000 in the South in 1950-2019,but both decreased to 2.0/100 000 in 2020-2022.Differences in trends between age groups are reflected in the rising phase in 2004-2019,with the persons aged 3-＜7 years old and 7-＜10 years old rising more than the other age groups,with an 18-fold and 9-fold increase,respectively,relative to 2003.Kinder-garden children and students were the main affected groups,and there was a tendency for the age of onset to be lower.The average interval between annual morbidity peaks was 4.73 years,and the fluctuation risk of incidence and mortality decreased to a lower level after 1979.From 1963 onwards,a stable bimodal seasonal pattern has emerged,with peaks in spring and winter(March to June)and in winter and spring(November to January of the following year).From 1963 to 1984,the winter and spring peaks were higher than the spring and summer peaks,while after 1985,the latter was generally higher.Conclusions Scarlet fever in China has gone through high-level fluctuations,low-level epidemics,rebound,and decline,with a continuous decrease in the case-fatality ratio.The incidence is higher in the North than in the South,and kinder-garden children and students aged 3-＜10 years old are the main incidence groups.A relatively fixed epidemic cycle exists,but the fluctuation risk is low.Since 1963,a stable bimodal seasonal pattern has formed,with the peak gradually shifting from winter-spring to spring-summer.
NETL
NSTL
万方数据
