Abstract：Objective The impact of imported cases from overseas on the domestic epidemic of SARS-CoV-2 infection is becoming more and more serious; and hence, in-depth theoretical analysis of development of the epidemics in overseas countries will help the researchers have a better understanding of the spread and evolution of the epidemic of SARS-CoV-2 infection so as to better prevent and control the epidemic. Methods A non-extensive correction of the classic susceptible-infected-recovered (SIR) model was made and the q-SIR model was proposed to fit the growth law of confirmed cases over time in the United States, Iran, India, and the UnitedKingdom from the beginning of 2020 to early 2021. Phenomenological analysis on non-extensive statistical physics theory is also performed by combining the specific fitting results. Results The fitting parameters were closely related to the specific development of the epidemic in various countries. The existence of external interference made the original idealized system more complicated, and the non-extensive SIR model could better fit its development trend. For countries with similar epidemic development trends, the corresponding key fitting parameters were very close. More explicitly, the corresponding fitting parameters were: b=0.287, γ=15.546 and q=1.025 for United States, b=0.238, γ=17.793 and q=1.024 for Iran, b=0.753, γ=3.461 and q=1.127 for India, and b=0.745, γ=2.166 and q=1.125 for the United Kingdom. It could be found that the fitting parameters b, γ and q of the United States and Iran as well as those of India and the United Kingdom were relatively close. Conclusion The fitting parameter q can well reflect the degree of external interference received by the system. The more the external intervention, the greater the value of q.
刘洋, 王家乐, 于辰悦, 黄雨杰, 申可明, 刘旭升. 海外新冠感染疫情的非广延模型及其拟合分析[J]. 实用预防医学, 2023, 30(2): 245-249.
LIU Yang, WANG Jia-le, YU Chen-yue, HUANG Yu-jie, SHEN Ke-ming, LIU Xu-sheng. Non-extensive SIR model and its fitting analysis for the SARS-CoV-2 pandemic overseas. , 2023, 30(2): 245-249.
2023, Vol. 30 
