Epidemiological characteristics and environmental risk factors of hemorrhagic fever with renal syndrome in Wei River basin, China, 2005-2015

Abstract

Objective: To understand the epidemiological characteristics of hemorrhagic fever with renal syndrome (HFRS) in Wei River Basin from 2005 to 2015, and analyze the environmental factors that cause the differences of spatial distribution. Methods: HFRS reported cases in Wei River Basin from 2005 to 2015 were collected form "National Disease Reporting Information System" , and the epidemiological features of HFRS were analyzed. Boosted regression trees (BRT) model was applied to evaluate the environment factors on the geographical distribution of HFRS in Wei River basin at 5 km×5 km gird scale. Results: The number of HFRS cases was 18 629, and the average annual incidence from 2005-2015 in Wei River basin was 7.24/100 000. The highest morbidity was 15.18/100 000 in 2012. The middle and lower reaches of Wei River basin had high incidence of HFRS, such as Xi'an, Weinan city. Patients' age was mainly between 16 to 60, and the largest morbidity occured in people over 60 years old. Boosted regression trees modle identified building land, farmland coverage percentage and altitude had higher contribution to the distribution of HFRS. Conclusions: The epidemiological characteristics of HFRS changed significantly. Patients older than 60 years old were having the highest incidence rates. Environmental factors such as buildup land, farmland and altitude played important roles in the geographical distribution of HFRS in the Wei River basin.