15. Forecasting the Monkeypox Outbreak: Using a SIR Epidemic Model

Abstract

Abstract Background Monkeypox virus person-to-person transmission mostly occurs by personal contact with an infected individual or surface. We used the classical susceptible-infectious-removed (SIR) epidemic model (Figure 1) to forecast the virus spread in a simulated population. Diagram of the SIR epidemic model Methods SIR model equations (ds/dt = −βsi; di/dt = βsi − µi; dr/dt = µi) were applied. We assumed an infection rate β = 9%; recovery rate µ = 100%; incubation period ranged from 4 to 21 days; length of a timestep = 15 days. Initially 150 infected individuals in a N= 10,000 population were organized in a lattice format (Figure 2) in which everyone has the same number of connections. Schematic infection process: Initial condition with a susceptible population (white circles); we put a few infected individuals (red circles); the infection spreads through the nearest neighbors; then, the previously infected population gets recovered (blue circles) and the virus transmission continues. Results Around 45 days after the transmission started, we obtained a maximum incidence of 2.5% (Figure 3) of infection in the population. At this time, 0.5% of the infected cases will be recovered from monkeypox infection. If the fraction of initially infected cases is smaller than 150/10,000, our simulations show that the outbreak would end in the early days. Numeric simulation of the SIR epidemic model in a lattice format and using β = 9%, µ = 100% and N = 10,000 Conclusion Applying our results to the US population (335 million), almost 10 million people might be affected by monkeypox. Considering that infected people should be isolated for up to 21 days, this could lead to negative impacts on the economy as people would be out of their work environments. In addition, monkeypox could put even more pressure on the health system already worn out by the COVID-19 pandemic. This study might be used by health agencies to plan coordinated actions to contain the spread of monkeypox virus. Disclosures All Authors: No reported disclosures.