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Brucellosis, a zoonotic disease, has brought about enormous human suffering and tremendous economic burden to animal husbandry in China. However, Inner Mongolia is the hardest hit area of brucellosis in China. A total of 132,037 human cases have been reported from 2010 to 2020. Endogenous mechanisms of brucellosis spreading across Inner Mongolia till remains to be revealed. We propose a periodic epidemic model to investigate the effect of periodic parameter changes on brucellosis epidemics. Then we evaluate the basic reproduction number R 0 and analyze the global dynamics of the model. Furthermore, key parameters related to periodic transmission are estimated based on the monthly data of human brucellosis cases and the trend of newly infected human brucellosis cases are predicted in Inner Mongolia. Our modeling results illustrate that periodical birth and sheep shearing play a significant role in inducing periodical outbreak of brucellosis in Inner Mongolia. Moreover, it is exhibited that the annual peak number and the final scale of human brucellosis cases will be reduced dramatically with the delayed peak time of sheep birth. While the annual peak time will be lagged and the annual peak number will be decreased as the peak time of sheep shearing is postponed. In addition, we discover that it is difficult to stem brucellosis even if all sheep are vaccinated besides ewes. Nevertheless, the detection rate exceed a certain value 0.032 or the decaying rate of Brucella surpass a critical value 0.585, the human brucellosis can be regulated in Inner Mongolia according to the sensitivity analysis of R 0 . The insights shed herein may contribute to the careful implementation of brucellosis control strategies in other regions. [ABSTRACT FROM AUTHOR]

At present, the prevention and control situation of human and animal brucellosis in China is grim and complex. Given the current epidemic situation, prevention and control difficulties, and actual needs of brucellosis, investigating the key environmental factors of human brucellosis is helpful for the effective prevention and control of the disease. The research aims are to understand what factors are driving the changes in human brucellosis. We establish a compartmental model to explain the periodic transmission dynamics of brucellosis, then evaluate the effective reproduction number, and quantify the brucella in the environment of Inner Mongolia from January 2016 to December 2020. The step-wise regression is used to determine the possible factors that are significantly correlated with the incidence of human brucellosis and brucella-contaminated environment, meteorological factors. Machine learning methods random forest and Xgboost are used to capture the relative importance of factors with statistical significance. The results show that multiple driving forces contribute to the transmission of human brucellosis, including the brucella-contaminated environment and meteorological factors. The brucella-contaminated environment accelerates the risk of human brucellosis, and clearly and strongly explains changes in the incidence of human brucellosis in Inner Mongolia. The impact of meteorological factors is indispensable, especially those with time delay. There is a significant correlation between precipitation, relative humidity, atmospheric pressure, and human brucellosis in Inner Mongolia. The proposed models aid surveillance and the early control of human brucellosis outbreaks. • We explore the relationship between environmental factors and human brucellosis (HB). • Indirect contact with environments matters most changes of HB. • Meteorological factors have the indispensable role in HB. • The influence of meteorological factors on HB has time delay. • Total precipitation, relative humidity, atmospheric pressure are correlated with HB. [ABSTRACT FROM AUTHOR]