The influence of agricultural mechanization progress on epidemiological characteristics of hemorrhagic fever with renal syndrome in Qingdao areas

Abstract

Objective To explore the influence of agricultural mechanization progress on epidemic intensity of hemorrhagic fever with renal syndrome (HFRS) so as to provide reference for prevention and control of HFRS in rural areas. Methods Data of HFRS epidemics and agricultural mechanization progress of Qingdao City and five main epidemic areas of HFRS were collected by retrospective analysis methods. Agricultural mechanization progress, time distribution, incidence rate of HFRS and capture rate of rats were compared, respectively. Risk factors were analyzed by case-control study using simple random sampling method. Cases of case group were selected from HFRS cases of Jiaonan County recovered between 2012 and 2013. The control group was healthy residents with a equal number of the case group. Residential locations, work ways, rodent infestation at work locations and in residential areas and skin injury conditions were surveyed by a household questionnaire survey. Results Agricultural machinery gross power of Qingdao City was developed from 174.76 megawatts of electricity (mwe) in 1985 to 854.00 mwe in 2015. The comprehensive mechanization degree marched from 60.0% in 1994 to 90.2% in 2015. HFRS incidence in Qingdao City declined from the first epidemic peak (1986) of 32.97/100 000 to the third peak (2012) of 3.54/100 000. HFRS incidence in Jiaonan, Jiaozhou, Pingdu, Laixi, Jimo cities reduced from the first epidemic peak (1985 or 1986) of 101.25/100 000, 86.37/100 000, 35.80/100 000, 11.55/100 000, 8.13/100 000 to the third peak (2012) of 14.68/100 000, 4.43/100 000, 2.33/100 000, 6.02/100 000, 3.26/100 000. The platform stage of epidemic peak in autumn and winter shortened from 4 or 5 months to 2 months. The capture rate of rats fluctuated around 2%. The infection risk of small farm implements or handwork was greater than huge mechanization (OR= 0.01, P < 0.01) . Conclusions Agricultural mechanization changes the agricultural activity patterns to a large extent and lowers the HFRS epidemic by minimizing the risk of infection and shortening the platform stage of epidemic peak. The higher the degree of mechanization, the lower the epidemic intensity. Key words: Hemorrhagic fever with renal syndrome; Agricultural machinery gross power; Comprehensive mechanization; Capture rate; Incidence