Epidemiological and time series analysis of haemorrhagic fever with renal syndrome from 2004 to 2017 in Shandong Province, China

Chao Zhang,Zhen Ye,Cuifang Nie,Yuanying Zhang,Shuying Yi,Baojia Wang,Haijun Cao,Liu Li,Junmei Wang,Xiao Fu

doi:10.1038/s41598-019-50878-7

Abstract

Shandong Province is an area of China with a high incidence of haemorrhagic fever with renal syndrome (HFRS); however, the general epidemic trend of HFRS in Shandong remains unclear. Therefore, we established a mathematical model to predict the incidence trend of HFRS and used Joinpoint regression analysis, a generalised additive model (GAM), and other methods to evaluate the data. Incidence data from the first half of 2018 were included in a range predicted by a modified sum autoregressive integrated moving average-support vector machine (ARIMA-SVM) combination model. The highest incidence of HFRS occurred in October and November, and the annual mortality rate decreased by 7.3% (p < 0.05) from 2004 to 2017. In cold months, the incidence of HFRS increased by 4%, −1%, and 0.8% for every unit increase in temperature, relative humidity, and rainfall, respectively; in warm months, this incidence changed by 2%, −3%, and 0% respectively. Overall, HFRS incidence and mortality in Shandong showed a downward trend over the past 10 years. In both cold and warm months, the effects of temperature, relative humidity, and rainfall on HFRS incidence varied. A modified ARIMA-SVM combination model could effectively predict the occurrence of HFRS.

Highlights

Haemorrhagic fever with renal syndrome (HFRS) is primarily distributed throughout Eurasia
An epidemiological analysis was conducted on the epidemic characteristics of haemorrhagic fever with renal syndrome (HFRS) in Shandong Province, with an aim to provide a theoretical basis for formulating reasonable disease prevention and control measures
From 2004 to 2017, there were 20,981 cases of HFRS and 247 deaths in Shandong Province, which accounted for 11.7% and 14.1% of the national total, respectively (Shandong accounts for approximately 7.1% of the national population)

Summary

Introduction

Haemorrhagic fever with renal syndrome (HFRS) is primarily distributed throughout Eurasia. China has one of the highest incidence rates of HFRS and is the location for the most serious epidemics. China has the highest number of patients with HFRS in the world[1,2], and Shandong Province is a focal point for HFRS incidence within the country. In Zibo, a prefecture-level city in Shandong Province, hantavirus antigens were detected in 5.2% of rodents, and in residential areas, the brown rat (R. norvegicus) and the house mouse (M. musculus) had infection rates of 5.3% and 2.4%, respectively[10]. Risk factors for hantavirus infection include involvement in outdoor activities, such as working in fields and forests, and exposure to peridomestic rodents. HFRS is transmitted to humans through rodents, and this transmission can be affected by meteorological factors[12]. Our study had the following characteristics: (1) a large number of cases, (2) a long time span, and (3) an increased predictive accuracy owing to twice revising a time series model

Methods

Results

Discussion

Conclusion