Shigellosis seasonality and transmission characteristics in different areas of China: A modelling study

Zeyu Zhao; Meng Yang; Jinlong Lv; Qingqing Hu; Qiuping Chen; Zhao Lei; Mingzhai Wang; Hao Zhang; Xiongjie Zhai; Benhua Zhao; Yanhua Su; Yong Chen; Xu-Sheng Zhang; Jing-An Cui; Roger Frutos; Tianmu Chen

doi:10.1016/j.idm.2022.05.003

Shigellosis seasonality and transmission characteristics in different areas of China: A modelling study

Infect Dis Model. 2022 May 23;7(2):161-178. doi: 10.1016/j.idm.2022.05.003. eCollection 2022 Jun.

Authors

Zeyu Zhao^{1

2}, Meng Yang¹, Jinlong Lv³, Qingqing Hu⁴, Qiuping Chen², Zhao Lei¹, Mingzhai Wang⁵, Hao Zhang⁶, Xiongjie Zhai⁷, Benhua Zhao¹, Yanhua Su¹, Yong Chen⁸, Xu-Sheng Zhang⁹, Jing-An Cui³, Roger Frutos², Tianmu Chen¹

Affiliations

¹ State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen City, People's Republic of China.
² CIRAD, UMR 17, Intertryp, Montpellier, France.
³ Department of Mathematics, School of Science, Beijing University of Civil Engineering and Architecture, Beijing, 102616, People's Republic of China.
⁴ Division of Public Health, School of Medicine, University of Utah, 201 Presidents Circle, Salt Lake City, 84112, Utah, USA.
⁵ Xiamen Center for Disease Control and Prevention, Xiamen City, Fujian Province, People's Republic of China.
⁶ Yichang Center for Disease Control and Prevention, Yichang City, Hubei Province, People's Republic of China.
⁷ Longde County Center for Disease Control and Prevention, Guyuan City, Ningxia Hui Autonomous Region, People's Republic of China.
⁸ Department of Stomatology, School of Medicine, Xiamen University People's Republic of China.
⁹ Public Health England, London, United Kingdom.

Abstract

Objective: In China, the burden of shigellosis is unevenly distributed, notably across various ages and geographical areas. Shigellosis temporal trends appear to be seasonal. We should clarify seasonal warnings and regional transmission patterns.

Method: This study adopted a Logistic model to assess the seasonality and a dynamics model to compare the transmission in different areas. The next-generation matrix was used to calculate the effective reproduction number (R _eff) to quantify the transmissibility.

Results: In China, the rate of shigellosis fell from 35.12 cases per 100,000 people in 2005 to 7.85 cases per 100,000 people in 2017, peaking in June and August. After simulation by the Logistic model, the 'peak time' is mainly concentrated from mid-June to mid-July. China's 'early warning time' is primarily focused on from April to May. We predict the 'peak time' of shigellosis is the 6.30th month and the 'early warning time' is 3.87th month in 2021. According to the dynamics model results, the water/food transfer pathway has been mostly blocked off. The transmissibility of different regions varies greatly, such as the mean R _eff of Longde County (3.76) is higher than Xiamen City (3.15), higher than Chuxiong City (2.52), and higher than Yichang City (1.70).

Conclusion: The 'early warning time' for shigellosis in China is from April to May every year, and it may continue to advance in the future, such as the early warning time in 2021 is in mid-March. Furthermore, we should focus on preventing and controlling the person-to-person route of shigellosis and stratified deploy prevention and control measures according to the regional transmission.

Keywords: ARIMA, Autoregressive Integrated Moving Average (model); CDC, Center of Chinese Center for Disease Control and Prevention; CI, confidence interval; Early warning; MSM, men who sex with a man; ODE, ordinary differential equation; R0, basic reproductive number; R2, Coefficient of determination; Reff, effective reproduction number; SD, standard deviation; SEIAR, Susceptible–Exposed–Infectious/Asymptomatic–Recovered (model); SEIARW, Susceptible–Exposed–Infectious/Asymptomatic–Recovered-Water/Food (model); Seasonality; Shigellosis; Transmissibility.