Spatial epidemiology plays an important role in control and prevention of diseases / 中华流行病学杂志

Spatial epidemiology is a new branch of epidemiology that aims to map the spatial distribution and characteristics as well as to explore the associated influencing factors of diseases by using the geographic information system and other spatial technologies. In recent years, with the rapid development of information-related modern technology, improvement of accessibility on health - related services, natural environment, social and economic big data etc., spatial epidemiology has made considerable progress in both theory and practice and played more important roles in the public health area of China.

Epidemiological features of hepatitis C and its related influencing factors in Shandong province, 2007-2016 / 中华流行病学杂志

Objective: To analyze the epidemiological characteristics, dynamic trend of development and related influencing factors of hepatitis C in Shandong, China, 2007-2016, also to provide epidemiological evidence for prevention and control of HCV. Methods: National surveillance data of hepatitis C from 2007 to 2016 in Shandong was used, with distribution and clustering map of hepatitis C drawn at the county level. Panel Poisson regression was used to explore the influencing factors of hepatitis C at the city level. Results: The incidence of hepatitis C in Shandong increased from 1.49/100 000 in 2007 to 4.72/100 000 in 2016, with the high incidence mainly clustered in the urban regions in Jinan, Zibo, Weihai et al. and surrounding vicinities. Majority of the cases were young adults, with 53.16% (14 711/27 671) of them being farmers. Results from the Multiple panel Poisson regression analysis indicated that factors as: population density (aIRR=1.07, 95%CI: 1.05-1.10), number of hospital per hundred thousand people shared (aIRR=1.16, 95%CI: 1.08-1.24), expenditure of medical fee in rural (aIRR=1.21, 95%CI: 1.08-1.37) and the proportion of the tertiary industry (aIRR=1.08, 95%CI: 1.07-1.09) were all correlated to the incidence of hepatitis C. Conclusions: The incidence of hepatitis C had been increasing rapidly in recent years, in Shandong. Prevention and control of HCV should focus on high risk population. In addition, rural, especially in areas with lower economics provision should be under more attentions, so as to find more concealed cases for early treatment.

Analysis on the spatial-temporal characteristics of hand-foot-mouth disease in Shaanxi province, 2009-2013 / 中华流行病学杂志

Objective: To study the spatial-temporal dynamical features of hand-foot-mouth disease (HFMD) in Shaanxi Province, so as to provide evidence for the development of relative prevention and control programs on HFMD. Methods: Surveillance data of HFMD was collected from the China Information System for Diseases Control and Prevention from 2009 to 2013. Related data on population and gross domestic product (GDP) was obtained from Shaanxi Statistical Yearbook. Statistical tools as R3.4.1, ArcGIS 10.2 and SaTScan 9.2 software were used to describe the spatial-temporal distribution of the disease. Power-law method on spatial-temporal-multicomponent model was used to analyze the spatial-temporal evolution of the HFMD epidemics in Shaanxi Province. Results: A total of 229 904 cases of HFMD were reported in Shaanxi Province from 2009 to 2013, with an average annual incidence as 122.50 per 100 000. Obvious seasonal characteristics were noticed, with 71.71% of the total cases identified between April and July. Counties with high incidence were mainly distributed in the mid-and east parts of Guanzhong area. Through temporal and spatial scan statistics, we identified that ClassⅠ clustering area was fixed to the central and southeast regions of Shaanxi province which were around Xi'an City between 2009 and 2013, with the relative risk (RR) as 2.24, ranging from 2.18 to 3.08. Results from Power-law analysis showed that the continuous follow-up impact from the previous HFMD epidemics appeared strong in Tongguan, Pucheng districts of Weinan City and Weiyang district of Xi'an, with autoregressive components as 1.14, 0.97 and 0.89, respectively. The risk of HFMD seemed high in Huayin city, Changan and Yanta districts and with the endemic components as 5.08, 4.12 and 4.08, respectively. Impact of the epidemics on nearby districts was largely seen in Lianhu district of Xi'an, Wugong district of Xianyang and Gaoling district of Xi'an with epidemic components as 2.12, 2.08 and 1.77, respectively. The etiological constituents of HFMD were mainly Enterovirus 71 between 2009 and 2012, while HFMD was mainly caused by other entero-viruses, in 2013. Conclusion: Significant spatial-temporal heterogeneity of HFMD was seen in Shaanxi province, which called for specific strategies to be developed in the highly endemic areas.

Epidemiological characteristics and environmental risk factors of hemorrhagic fever with renal syndrome in Wei River basin, China, 2005-2015 / 中华流行病学杂志

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.

Characteristics on spatial and temporal distribution as well as the driving effect of meteorological factors on brucellosis in Datong city, Shanxi province, 2005-2015 / 中华流行病学杂志

Objective: To explore the spatio-temporal epidemic trends and related driving effects of meteorological factors on brucellosis in Datong city, Shanxi province, from 2005 to 2015. Methods: We collected the surveillance data on brucellosis and related meteorological data in Datong city from 2005 to 2015, to describe the epidemic characteristics of the disease. Quasi-Poisson distribution lag non-liner model (DLNM) was built to explore the driving effect of monthly meteorological data on the disease. Results: From 2005 to 2015, Datong city reported a total of 17 311 cases of brucellosis including one death, with the annual average incidence as 47.43 per 100 000 persons. A rising trend was seen during the study period. The monthly incidence of Brucellosis presented an obvious curve with a major peak from March to June, accounted for 48.40% of the total cases. The high incidence areas in the city gradually expanded from the northeast and southeast to the western areas. Results from the DLNM studies suggested that seasonality of brucellosis in Datong was significantly affected by metrological factors such as evaporation, rainfall and temperature. The peak of delayed effect appeared the highest when the monthly cumulative evaporation capacity was 140-260 mm and the monthly cumulative rainfall was 20-60 mm with lag less than 1 month or the monthly temperature was -13 ℃ with lag of 4-5 months. Conclusions: The incidence of human brucellosis in Datong city increased significantly from 2005 to 2015. Meteorological factors such as evaporation, rainfall, temperature all showed significant driving effects on the disease.