All three of these graphs can give us the idea of a population. Logistic graphs are the most realistic!!

What is Epidemiology?

According to National Institute on Deafness and other Disorders (NIDD), epidemiology is a branch of math sciences that can track the spread of an epidemic or a pandemic and investigates the factors that can show a presence or lack of a disease in an area.

How do Epidemiologists Model Epidemics and Who were affected?

Epidemiologists use categories to seperate the affected population into 3 or more groups. The most common models used are the SIR and SEIR models. The SIR model shows the susceptible, infected, and the removed group of the population, and the SEIR model shows the susceptible, exposed, infected, and the removed groups of a population. At any time, the population is split between these groups, meaning we have no population growth. 

These are all examples of the SIR Model where :   

a = infection rate,       b=recovery rate,   and N= total population.

Equation 1 is negative because less people are coming out of being susceptible and going into infected. The infected equation is positive because more people are getting infected and the variable "b" becomes negative because more people will be recovering which takes some people out of the infected population. 

We can represent the SIR model using differential equations and coding to help us understand the spread of disease. 

How chickenpox is spread animation