قارن الطرق

	نماذج الحجرات الوبائية المستوطنة (SIS, SIRS, SIRV)	رقم التكاثر (R0 و Rt)
المجال	علم الأوبئة	علم الأوبئة
العائلة	Regression model	Regression model
سنة النشأة	2000	1990
صاحب الطريقة	Herbert Hethcote	Diekmann, Heesterbeek & Metz
النوع	Compartmental ODE model	Threshold parameter for epidemic spread
المصدر التأسيسي	Hethcote, H. W. (2000). The mathematics of infectious diseases. SIAM Review, 42(4), 599–653.	Diekmann, O., Heesterbeek, J. A. P., & Metz, J. A. J. (1990). On the definition and the computation of the basic reproduction ratio R0. Journal of Mathematical Biology, 28(4), 365–382.
الأسماء البديلة	SIS Model, SIRS Model, SIRV Model, Endemic Disease Models	Basic Reproduction Ratio, Effective Reproduction Number, Net Reproduction Number, Temel Üreme Sayısı
ذات صلة	3	2
الملخص	Endemic compartmental models extend the classical SIR framework to capture diseases that persist indefinitely in a population rather than burning out after a single epidemic wave. The SIS model allows recovered individuals to return to susceptibility immediately; SIRS introduces temporary immunity before loss; SIRV adds a vaccinated compartment. Together these models are foundational tools for studying diseases such as influenza, gonorrhea, and seasonal pathogens where reinfection or waning immunity is epidemiologically central.	The basic reproduction number R0 is the expected number of secondary infections produced by a single infectious individual introduced into a fully susceptible population. Formally defined and computationally grounded by Diekmann, Heesterbeek, and Metz in 1990 using the next-generation matrix approach, R0 serves as the central threshold parameter in mathematical epidemiology: if R0 > 1, an epidemic can establish itself; if R0 < 1, the outbreak dies out. The effective reproduction number Rt extends this to partially immune or partially susceptible populations over time.