10.7 Modeling the spread of a disease

Main points:

• The S-I-R Model
○ S=the number of susceptibles, the people who are not yet sick but who could become sick
○ I=the number of infecteds, the people who are currently sick
○ R=the number of recovered, or removed, the people who have been sick and can no longer infect others or be reinfected
○ dS/dt=-aSI
○ dI/dt=aSI-bI
○ dR/dt=bI
○ Threshold population = b/a
§ If S0 is above --> epidemic
§ If S0 is below --> no epidemic

Challenges:

I understood the basics of the S-I-R model, but nevertheless had troubles fully understanding it. Part where trajectories in the phase plane were introduced made me confused, because I didn’t completely understand what the trajectories are. I think I will understand the topic better after tomorrow's class.

Reflection:

Even I am not doing biology, I have done it in the past and I do found it interesting to study the patterns of diseases spreading. It is going to be useful for just my general knowledge and also possibly useful as I am interested in international studies. Today's studying was spred over 2 hours which proved to be very unproductive in the end (due to several distractions) so I need to make sure that in future I allocate more specific timeframe for my math studying.