The Impact of Coinfections and Their Simultaneous Transmission on Antigenic Diversity and Epidemic Cycling of Infectious Diseases

Figure 7

Impact of strain interactions on coexistence and sustained oscillation in incidence of infections. The host population was initially endemic with strain 𝑎 and then challenged with strain 𝑏. Two strains are assumed to be equally transmissible with 𝛽_𝑎=𝛽_𝑏=0.75 day⁻¹ and infectious period (1/𝛾_𝑎=1/𝛾_𝑏) = 2 days (i.e., 𝑅^𝑎₀=𝑅^𝑏₀=1.5). Coinfection can simultaneously transmit at a rate (𝛽_𝑑)=0.375 day⁻¹ and with an infectious period (1/𝛾_𝑑)=2 days. Other parameters are the immunity period (1/𝜎)=3 years and life span (1/𝜇)=55 years.