Spatial-temporal distribution of human brucellosis in mainland China from 2004 to 2017 and an analysis of social and environmental factors

Abstract

Background: This study aimed to describe the changing distribution of human brucellosis between 2004 and 2017 in mainland China and seek scientific evidence of the relationship between socioeconomic , environmental, and ecological factors and human brucellosis incidence. Methods: The annual numbers of brucellosis cases and incidence rates from 31 provinces in mainland China between 2004 and 2017 were obtained from the Data-Center for China Public Health Science. The number of monthly brucellosis cases in 2018 was obtained from the Chinese Center for Disease Control and Prevention. The electronic map of the People's Republic of China was downloaded from the National Earth System Science Data Sharing Platform. Human population density, gross domestic product (GDP), and an inventory of cattle and sheep at the end of each year from 2004 to 2017 were obtained from the National Bureau of Statistics of China. Annual rainfall data from 31 provinces in the People's Republic of China from 2004 to 2017 were collected from the China Meteorological Data Service Center. The risk distribution and changing trends of human brucellosis were mapped with ArcGIS. A cluster analysis was employed to identify geographical areas and periods with statistically significant incidence rates. Multivariate linear regression was used to determine possible factors that were significantly correlated with the presence of human brucellosis cases. Results: Human brucellosis cases have spread throughout the whole country. Human brucellosis cases occurred mostly from March to August and were concentrated from April to July. The inventory of sheep, GDP, and climate were significantly correlated with the presence of brucellosis cases in mainland China. Conclusions: The geographical expansion of human brucellosis in mainland China was observed, so did the highincidence clusters between 2004 and 2017. Most of the cases were reported during the early spring to early summer (February-August). Results from the multivariate linear regression suggested that the inventory of sheep, GDP, and climate were significantly associated with the incidence of human brucellosis in mainland China.

Epidemiological Characteristics and Spatiotemporal Trend Analysis of Human Brucellosis in China, 1950–2018

“…Our research showed that in China, the distribution of regions with high incidence of HB had almost no overlap with the distribution of high levels of per capita GDP. This was consistent with the conclusions of many previous studies [15,21]. A global study showed that countries with relatively high per capita GDP tend to have less brucellosis; another study showed that rainfall and per capita GDP in China's temperate regions are low and negatively related to the number of cattle and sheep.…”

“…In other time periods, although the p-value was not statistically significant, the correlation coefficients were all negative. This was similar to the result of another recently published paper [21].…”

“…In addition, the increasing living standards of the population have stimulated the demand for meat, which has led to an increase in the demand for animal husbandry and animal products [56]. However, there are still studies showing that in the subtropical region of China (southern China), the number of cattle and sheep, precipitation, and GDP per capita have hardly affected the occurrence of HB [21]. According to the results of our current research, we cannot give a direct reason for this observation.…”

“…First, the reasons for the development of local animal husbandry, which plays a vital role in the incidence of HB, should be considered. The areas where HB is highly concentrated have similar natural and social environments, which may also increase the risk of HB epidemics in these areas [6,21,39,57]. Another potential reason for the spatial distribution of HB is the relative economic disadvantage of the high-high districts.…”

“…Related articles on the spatiotemporal characteristics of HB have also appeared, but we found that most of these articles were based on a province as the research unit, and provide limited guidance for national HB prevention and control [17][18][19][20]. There have been few studies to date that have used the latest data with a long span [6,21]. Simultaneously, we observed that most studies were retrospective and focused on surveillance and prevention of brucellosis rather than prediction.…”