Spatio-temporal statistical analysis of epidemic situation of typhoid and paratyphoid fever in Chinese mainland from 2004 to 2018

Objective:To analyze the change trend and spatial distribution of typhoid/paratyphoid fever in 31 provinces, municipalities directly under the Central Government and autonomous regions in China from 2004 to 2018, so as to provide a basis for the prevention and control of typhoid/paratyphoid fever.Methods:Based on the typhoid and paratyphoid fever case data reported by the China Public Health Science Data Center platform from 2004 to 2018, the data were described and the spatio-temporal effect of the epidemic was analyzed by Joinpoint regression, spatial autocorrelation and spatial scanning.Results:The incidence of typhoid and paratyphoid fever in Chinese mainland decreased year by year from 2004 to 2018.Children under 5 years old were the main population and the incidence rate increased.The annual percent change (APC) from 2011 to 2018 was 6.5% (P< 0.05).There was a positive spatial correlation between the incidence of typhoid and paratyphoid fever from 2004 to 2018(Moran's I index was 0.087-0.389, Z> 1.960, P< 0.05).Spatio-temporal scanning showed that the aggregation time was from 2004 to 2006(LLR=29, 380.06, RR=2.70, P< 0.001)and the season was from April to September, typhoid fever mainly concentrated in Yunnan, Guangxi and Guizhou(LLR=77, 653.50, RR=4.571, P< 0.001), and paratyphoid fever mainly concentrated in Guangxi, Guizhou, Yunnan, Zhejiang, Jiangxi and Hunan (LLR=54, 280.50, RR=3.455, P< 0.001).Conclusion:The incidence of typhoid and paratyphoid fever in Chinese mainland is decreasing year by year, and children under 5 years old are still the main population.The epidemic situation shows obvious temporal and spatial effect, and is prone to occur in summer and in southern China.